eLinux.org - User contributions [en]

Real Time Tech Zone 2013

2013-02-23T00:10:43Z

Frowand: /* Presentations */

==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
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To add a link to your new page use the following wiki link format:

<nowiki>[[My New Page]]</nowiki>

[[Real_Time_Tech_Zone_2013#Problems_and_Issues]]

Save this page/section and your new page link will appear in Red. Click it and begin editing your new page.
</div>
----

Welcome to the Real-Time [[Tech Zones|Tech Zone]] for ELC 2013!!

This page is dedicated to preserving information and discussions about Linux Real-time from
the Embedded Linux Conference. You should think of this page like a "scratchpad" to record
your thoughts and discussions from the conference. Most of us take notes at an event, at a talk
that interests us, or after we learn something new and useful from another attendee.
Here's a place to record those notes in public, so that not only you can
access them after the event, but everyone else can as well.

== Discussions ==
What discussions did people have in the tech zone?

=== Problems and Issues ===
What issues do you have with "Real Time"?

* The primary issue that I have with the real-time patch is why its still a patch and not in mainline. We seem to be asymptotically approaching inclusion. But as with any asymptote, you never seem to reach zero. TG and SR and others are working to keep the patch caught up with reasonably recent kernels, but that's a lot of work that detracts from making further progress on the core issues of determinism in Linux.

What are some possible solutions?

* The best thing would be to finally round the corner on the inclusion of the real-time patch into mainline. I realize that there differing views on the future of Linux. But, since the RT patch has seemingly minimal impact on mainline if it's not enabled, maybe 2013 will be the year that it finally makes mainline? One can only hope.

What's going on in the wider community to address these issues?

* Stephen Rostedt had a good presentation on the RT patch and where it stands in his mind. Check out his presentation from the conference. There are many of us who use the RT patch on our systems. But, it's unclear to many of us who don't follow the LKML daily as to what progress is being made in the kernel community. Can anyone enlighten the rest of us?

== People ==
Who at ELC is interested in "Real Time"?

* Frank Rowand
* Tim Bird
* Mike Anderson

== Presentation notes ==
What presentations at ELC, on the subject of "Real Time" did people like? Why?

Put your notes about the "Real Time" presentations from ELC here...

=== Presentations ===

* Wed 2/20 Frank Rowand '''Using and Understanding the Real-Time Cyclictest Benchmark'''
** A conceptual description of the cyclictest algorithm
** How to use cyclictest to understand the real time latency of your system
** What does cyclictest data typically look like for different architectures?
** cyclictest options are very powerful and must be selected with care
** There are several different formats of data, which provide different views of system behavior
** There are debug options to help investigate causes of large latencies
* Wed 2/20 Steven Rostedt '''Understanding PREEMPT-RT (The Real-Time Patch)'''
** Steven is the Stable RT Branches maintainer
** The math of trebuchets
** Definition of real time
** Varying levels of preemption available in Linux
** The technology in the PREEMPT_RT Linux kernel that enable real time
*** Locks
*** Preemption
*** Priority inheritance
*** Threaded interrupts
*** Disabling interrupts
*** percpu
*** nohz
*** user space considerations
** Current issues that are being worked on
* Wed 2/20 Brent Roman '''Making Linux Do Hard Real-Time'''
** An experience of how PREEMPT_RT Linux is used in a scientific context
* Thu 2/21 Yoshitake Kobayashi '''Deadline Miss Detection with SCHED_DEADLINE'''
** SCHED_DEADLINE is being driven by real time use cases
** Definition and description of deadlline scheduler
** Comparison of deadline algorithms
** How to use the deadline scheduler
** Example of how it works
** Granularity improvement
** Deadline miss detectioin
** SCHED_DEADLINE is being driven by real time use cases

=== Presentations that incidentally touched on real time ===

* Thu 2/21 Robert Rose '''Keynote: SpaceX | Moore's Law to Mars'''
** The space vehicles use PREEMPT_RT Linux
* Thu 2/21 Alison Chaiken '''Embedded Linux Takes on the Hard Problems of Automotive'''
** Are real-time IPC guarantees possible with IP?
** CANBUS vs IP networking
* Fri 2/22 Mathieu Poirier '''In Kernel Switcher: A Solution to Suppport ARM's New big, LITTLE Implementation'''
** Power saving and real time are like oil and water. Real time is not yet a consideration in the big, LITTLE world.
* Fri 2/22 Pantelis Antoniou '''Adventures in (Simulated) Asymmetric Scheduling'''
** Q: Is the deadline schedular on the radar as a technology that can assist big.LITTLE scheduling? A: No
* Fri 2/22 Gregoire Gentil '''Lessons Learned In Designing a Self-Video Self-Hovering Nano Copter'''
** PREEMPT_RT is one scheduling solution that was explored

[[Category:ELC]]
[[Category:2013]]
[[Category:Tech Zone]]

Real Time Tech Zone 2013

2013-02-22T23:08:52Z

Frowand: /* Presentations */

==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0 1em 1em 1em; background-color:#ffffcc; align:right; ">
To add a link to your new page use the following wiki link format:

<nowiki>[[My New Page]]</nowiki>

[[Real_Time_Tech_Zone_2013#Problems_and_Issues]]

Save this page/section and your new page link will appear in Red. Click it and begin editing your new page.
</div>
----

Welcome to the Real-Time [[Tech Zones|Tech Zone]] for ELC 2013!!

This page is dedicated to preserving information and discussions about Linux Real-time from
the Embedded Linux Conference. You should think of this page like a "scratchpad" to record
your thoughts and discussions from the conference. Most of us take notes at an event, at a talk
that interests us, or after we learn something new and useful from another attendee.
Here's a place to record those notes in public, so that not only you can
access them after the event, but everyone else can as well.

== Discussions ==
What discussions did people have in the tech zone?

=== Problems and Issues ===
What issues do you have with "Real Time"?

* The primary issue that I have with the real-time patch is why its still a patch and not in mainline. We seem to be asymptotically approaching inclusion. But as with any asymptote, you never seem to reach zero. TG and SR and others are working to keep the patch caught up with reasonably recent kernels, but that's a lot of work that detracts from making further progress on the core issues of determinism in Linux.

What are some possible solutions?

* The best thing would be to finally round the corner on the inclusion of the real-time patch into mainline. I realize that there differing views on the future of Linux. But, since the RT patch has seemingly minimal impact on mainline if it's not enabled, maybe 2013 will be the year that it finally makes mainline? One can only hope.

What's going on in the wider community to address these issues?

* Stephen Rostedt had a good presentation on the RT patch and where it stands in his mind. Check out his presentation from the conference. There are many of us who use the RT patch on our systems. But, it's unclear to many of us who don't follow the LKML daily as to what progress is being made in the kernel community. Can anyone enlighten the rest of us?

== People ==
Who at ELC is interested in "Real Time"?

* Frank Rowand
* Tim Bird
* Mike Anderson

== Presentation notes ==
What presentations at ELC, on the subject of "Real Time" did people like? Why?

Put your notes about the "Real Time" presentations from ELC here...

=== Presentations ===

* Wed 2/20 Frank Rowand '''Using and Understanding the Real-Time Cyclictest Benchmark'''
** A conceptual description of the cyclictest algorithm
** How to use cyclictest to understand the real time latency of your system
** What does cyclictest data typically look like for different architectures?
** cyclictest options are very powerful and must be selected with care
** There are several different formats of data, which provide different views of system behavior
** There are debug options to help investigate causes of large latencies
* Wed 2/20 Steven Rostedt '''Understanding PREEMPT-RT (The Real-Time Patch)'''
** Steven is the Stable RT Branches maintainer
** The math of trebuchets
** Definition of real time
** Varying levels of preemption available in Linux
** The technology in the PREEMPT_RT Linux kernel that enable real time
*** Locks
*** Preemption
*** Priority inheritance
*** Threaded interrupts
*** Disabling interrupts
*** percpu
*** nohz
*** user space considerations
** Current issues that are being worked on
* Wed 2/20 Brent Roman '''Making Linux Do Hard Real-Time'''
** An experience of how PREEMPT_RT Linux is used in a scientific context
* Thu 2/21 Yoshitake Kobayashi '''Deadline Miss Detection with SCHED_DEADLINE'''
** What the deadline scheduler is
** SCHED_DEADLINE is being driven by real time use cases

=== Presentations that incidentally touched on real time ===

* Thu 2/21 Robert Rose '''Keynote: SpaceX | Moore's Law to Mars'''
** The space vehicles use PREEMPT_RT Linux
* Thu 2/21 Alison Chaiken '''Embedded Linux Takes on the Hard Problems of Automotive'''
** Are real-time IPC guarantees possible with IP?
** CANBUS vs IP networking
* Fri 2/22 Mathieu Poirier '''In Kernel Switcher: A Solution to Suppport ARM's New big, LITTLE Implementation'''
** Power saving and real time are like oil and water. Real time is not yet a consideration in the big, LITTLE world.
* Fri 2/22 Pantelis Antoniou '''Adventures in (Simulated) Asymmetric Scheduling'''
** Q: Is the deadline schedular on the radar as a technology that can assist big.LITTLE scheduling? A: No
* Fri 2/22 Gregoire Gentil '''Lessons Learned In Designing a Self-Video Self-Hovering Nano Copter'''
** PREEMPT_RT is one scheduling solution that was explored

[[Category:ELC]]
[[Category:2013]]
[[Category:Tech Zone]]

Real Time Tech Zone 2013

2013-02-22T22:57:16Z

Frowand: /* Presentations that incidentally touched on real time */

==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0 1em 1em 1em; background-color:#ffffcc; align:right; ">
To add a link to your new page use the following wiki link format:

<nowiki>[[My New Page]]</nowiki>

[[Real_Time_Tech_Zone_2013#Problems_and_Issues]]

Save this page/section and your new page link will appear in Red. Click it and begin editing your new page.
</div>
----

Welcome to the Real-Time [[Tech Zones|Tech Zone]] for ELC 2013!!

This page is dedicated to preserving information and discussions about Linux Real-time from
the Embedded Linux Conference. You should think of this page like a "scratchpad" to record
your thoughts and discussions from the conference. Most of us take notes at an event, at a talk
that interests us, or after we learn something new and useful from another attendee.
Here's a place to record those notes in public, so that not only you can
access them after the event, but everyone else can as well.

== Discussions ==
What discussions did people have in the tech zone?

=== Problems and Issues ===
What issues do you have with "Real Time"?

* The primary issue that I have with the real-time patch is why its still a patch and not in mainline. We seem to be asymptotically approaching inclusion. But as with any asymptote, you never seem to reach zero. TG and SR and others are working to keep the patch caught up with reasonably recent kernels, but that's a lot of work that detracts from making further progress on the core issues of determinism in Linux.

What are some possible solutions?

* The best thing would be to finally round the corner on the inclusion of the real-time patch into mainline. I realize that there differing views on the future of Linux. But, since the RT patch has seemingly minimal impact on mainline if it's not enabled, maybe 2013 will be the year that it finally makes mainline? One can only hope.

What's going on in the wider community to address these issues?

* Stephen Rostedt had a good presentation on the RT patch and where it stands in his mind. Check out his presentation from the conference. There are many of us who use the RT patch on our systems. But, it's unclear to many of us who don't follow the LKML daily as to what progress is being made in the kernel community. Can anyone enlighten the rest of us?

== People ==
Who at ELC is interested in "Real Time"?

* Frank Rowand
* Tim Bird
* Mike Anderson

== Presentation notes ==
What presentations at ELC, on the subject of "Real Time" did people like? Why?

Put your notes about the "Real Time" presentations from ELC here...

=== Presentations ===

* Wed 2/20 Frank Rowand '''Using and Understanding the Real-Time Cyclictest Benchmark'''
** A conceptual description of the cyclictest algorithm
** How to use cyclictest to understand the real time latency of your system
** What does cyclictest data typically look like for different architectures?
** cyclictest options are very powerful and must be selected with care
** There are several different formats of data, which provide different views of system behavior
** There are debug options to help investigate causes of large latencies
* Wed 2/20 Steven Rostedt '''Understanding PREEMPT-RT (The Real-Time Patch)'''
** Steven is the Stable RT Branches maintainer
** The math of trebuchets
** The technology in the PREEMPT_RT Linux kernel that enable real time
** Current issues that are being worked on
* Wed 2/20 Brent Roman '''Making Linux Do Hard Real-Time'''
** An experience of how PREEMPT_RT Linux is used in a scientific context
* Thu 2/21 Yoshitake Kobayashi '''Deadline Miss Detection with SCHED_DEADLINE'''
** The deadline scheduler...

=== Presentations that incidentally touched on real time ===

* Thu 2/21 Robert Rose '''Keynote: SpaceX | Moore's Law to Mars'''
** The space vehicles use PREEMPT_RT Linux
* Thu 2/21 Alison Chaiken '''Embedded Linux Takes on the Hard Problems of Automotive'''
** Are real-time IPC guarantees possible with IP?
** CANBUS vs IP networking
* Fri 2/22 Mathieu Poirier '''In Kernel Switcher: A Solution to Suppport ARM's New big, LITTLE Implementation'''
** Power saving and real time are like oil and water. Real time is not yet a consideration in the big, LITTLE world.
* Fri 2/22 Pantelis Antoniou '''Adventures in (Simulated) Asymmetric Scheduling'''
** Q: Is the deadline schedular on the radar as a technology that can assist big.LITTLE scheduling? A: No
* Fri 2/22 Gregoire Gentil '''Lessons Learned In Designing a Self-Video Self-Hovering Nano Copter'''
** PREEMPT_RT is one scheduling solution that was explored

[[Category:ELC]]
[[Category:2013]]
[[Category:Tech Zone]]

Real Time Tech Zone 2013

2013-02-22T22:49:37Z

Frowand: /* Presentations that incidentally touched on real time */

==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0 1em 1em 1em; background-color:#ffffcc; align:right; ">
To add a link to your new page use the following wiki link format:

<nowiki>[[My New Page]]</nowiki>

[[Real_Time_Tech_Zone_2013#Problems_and_Issues]]

Save this page/section and your new page link will appear in Red. Click it and begin editing your new page.
</div>
----

Welcome to the Real-Time [[Tech Zones|Tech Zone]] for ELC 2013!!

This page is dedicated to preserving information and discussions about Linux Real-time from
the Embedded Linux Conference. You should think of this page like a "scratchpad" to record
your thoughts and discussions from the conference. Most of us take notes at an event, at a talk
that interests us, or after we learn something new and useful from another attendee.
Here's a place to record those notes in public, so that not only you can
access them after the event, but everyone else can as well.

== Discussions ==
What discussions did people have in the tech zone?

=== Problems and Issues ===
What issues do you have with "Real Time"?

* The primary issue that I have with the real-time patch is why its still a patch and not in mainline. We seem to be asymptotically approaching inclusion. But as with any asymptote, you never seem to reach zero. TG and SR and others are working to keep the patch caught up with reasonably recent kernels, but that's a lot of work that detracts from making further progress on the core issues of determinism in Linux.

What are some possible solutions?

* The best thing would be to finally round the corner on the inclusion of the real-time patch into mainline. I realize that there differing views on the future of Linux. But, since the RT patch has seemingly minimal impact on mainline if it's not enabled, maybe 2013 will be the year that it finally makes mainline? One can only hope.

What's going on in the wider community to address these issues?

* Stephen Rostedt had a good presentation on the RT patch and where it stands in his mind. Check out his presentation from the conference. There are many of us who use the RT patch on our systems. But, it's unclear to many of us who don't follow the LKML daily as to what progress is being made in the kernel community. Can anyone enlighten the rest of us?

== People ==
Who at ELC is interested in "Real Time"?

* Frank Rowand
* Tim Bird
* Mike Anderson

== Presentation notes ==
What presentations at ELC, on the subject of "Real Time" did people like? Why?

Put your notes about the "Real Time" presentations from ELC here...

=== Presentations ===

* Wed 2/20 Frank Rowand '''Using and Understanding the Real-Time Cyclictest Benchmark'''
** A conceptual description of the cyclictest algorithm
** How to use cyclictest to understand the real time latency of your system
** What does cyclictest data typically look like for different architectures?
** cyclictest options are very powerful and must be selected with care
** There are several different formats of data, which provide different views of system behavior
** There are debug options to help investigate causes of large latencies
* Wed 2/20 Steven Rostedt '''Understanding PREEMPT-RT (The Real-Time Patch)'''
** Steven is the Stable RT Branches maintainer
** The math of trebuchets
** The technology in the PREEMPT_RT Linux kernel that enable real time
** Current issues that are being worked on
* Wed 2/20 Brent Roman '''Making Linux Do Hard Real-Time'''
** An experience of how PREEMPT_RT Linux is used in a scientific context
* Thu 2/21 Yoshitake Kobayashi '''Deadline Miss Detection with SCHED_DEADLINE'''
** The deadline scheduler...

=== Presentations that incidentally touched on real time ===

* Thu 2/21 Robert Rose '''Keynote: SpaceX | Moore's Law to Mars'''
** The space vehicles use PREEMPT_RT Linux
* Fri 2/22 Mathieu Poirier '''In Kernel Switcher: A Solution to Suppport ARM's New big, LITTLE Implementation'''
** Power saving and real time are like oil and water. Real time is not yet a consideration in the big, LITTLE world.
* Fri 2/22 Pantelis Antoniou '''Adventures in (Simulated) Asymmetric Scheduling'''
** Q: Is the deadline schedular on the radar as a technology that can assist big.LITTLE scheduling? A: No
* Fri 2/22 Gregoire Gentil '''Lessons Learned In Designing a Self-Video Self-Hovering Nano Copter'''
** PREEMPT_RT is one scheduling solution that was explored

[[Category:ELC]]
[[Category:2013]]
[[Category:Tech Zone]]

Real Time Tech Zone 2013

2013-02-22T22:35:36Z

Frowand: /* Presentations that incidentally touched on real time */

==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0 1em 1em 1em; background-color:#ffffcc; align:right; ">
To add a link to your new page use the following wiki link format:

<nowiki>[[My New Page]]</nowiki>

[[Real_Time_Tech_Zone_2013#Problems_and_Issues]]

Save this page/section and your new page link will appear in Red. Click it and begin editing your new page.
</div>
----

Welcome to the Real-Time [[Tech Zones|Tech Zone]] for ELC 2013!!

This page is dedicated to preserving information and discussions about Linux Real-time from
the Embedded Linux Conference. You should think of this page like a "scratchpad" to record
your thoughts and discussions from the conference. Most of us take notes at an event, at a talk
that interests us, or after we learn something new and useful from another attendee.
Here's a place to record those notes in public, so that not only you can
access them after the event, but everyone else can as well.

== Discussions ==
What discussions did people have in the tech zone?

=== Problems and Issues ===
What issues do you have with "Real Time"?

* The primary issue that I have with the real-time patch is why its still a patch and not in mainline. We seem to be asymptotically approaching inclusion. But as with any asymptote, you never seem to reach zero. TG and SR and others are working to keep the patch caught up with reasonably recent kernels, but that's a lot of work that detracts from making further progress on the core issues of determinism in Linux.

What are some possible solutions?

* The best thing would be to finally round the corner on the inclusion of the real-time patch into mainline. I realize that there differing views on the future of Linux. But, since the RT patch has seemingly minimal impact on mainline if it's not enabled, maybe 2013 will be the year that it finally makes mainline? One can only hope.

What's going on in the wider community to address these issues?

* Stephen Rostedt had a good presentation on the RT patch and where it stands in his mind. Check out his presentation from the conference. There are many of us who use the RT patch on our systems. But, it's unclear to many of us who don't follow the LKML daily as to what progress is being made in the kernel community. Can anyone enlighten the rest of us?

== People ==
Who at ELC is interested in "Real Time"?

* Frank Rowand
* Tim Bird
* Mike Anderson

== Presentation notes ==
What presentations at ELC, on the subject of "Real Time" did people like? Why?

Put your notes about the "Real Time" presentations from ELC here...

=== Presentations ===

* Wed 2/20 Frank Rowand '''Using and Understanding the Real-Time Cyclictest Benchmark'''
** A conceptual description of the cyclictest algorithm
** How to use cyclictest to understand the real time latency of your system
** What does cyclictest data typically look like for different architectures?
** cyclictest options are very powerful and must be selected with care
** There are several different formats of data, which provide different views of system behavior
** There are debug options to help investigate causes of large latencies
* Wed 2/20 Steven Rostedt '''Understanding PREEMPT-RT (The Real-Time Patch)'''
** Steven is the Stable RT Branches maintainer
** The math of trebuchets
** The technology in the PREEMPT_RT Linux kernel that enable real time
** Current issues that are being worked on
* Wed 2/20 Brent Roman '''Making Linux Do Hard Real-Time'''
** An experience of how PREEMPT_RT Linux is used in a scientific context
* Thu 2/21 Yoshitake Kobayashi '''Deadline Miss Detection with SCHED_DEADLINE'''
** The deadline scheduler...

=== Presentations that incidentally touched on real time ===

* Thu 2/21 Robert Rose '''Keynote: SpaceX | Moore's Law to Mars'''
** The space vehicles use PREEMPT_RT Linux
* Fri 2/22 Mathieu Poirier '''In Kernel Switcher: A Solution to Suppport ARM's New big, LITTLE Implementation'''
** Power saving and real time are like oil and water. Real time is not yet a consideration in the big, LITTLE world.
* Fri 2/22 Gregoire Gentil '''Lessons Learned In Designing a Self-Video Self-Hovering Nano Copter'''
** PREEMPT_RT is one scheduling solution that was explored

[[Category:ELC]]
[[Category:2013]]
[[Category:Tech Zone]]

Real Time Tech Zone 2013

2013-02-22T22:35:06Z

Frowand: /* Presentations */

==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0 1em 1em 1em; background-color:#ffffcc; align:right; ">
To add a link to your new page use the following wiki link format:

<nowiki>[[My New Page]]</nowiki>

[[http://www.elinux.org/Real_Time_Tech_Zone_2013#Problems_and_Issues]]

Save this page/section and your new page link will appear in Red. Click it and begin editing your new page.
</div>
----

Welcome to the Real-Time [[Tech Zones|Tech Zone]] for ELC 2013!!

This page is dedicated to preserving information and discussions about Linux Real-time from
the Embedded Linux Conference. You should think of this page like a "scratchpad" to record
your thoughts and discussions from the conference. Most of us take notes at an event, at a talk
that interests us, or after we learn something new and useful from another attendee.
Here's a place to record those notes in public, so that not only you can
access them after the event, but everyone else can as well.

== Discussions ==
What discussions did people have in the tech zone?

=== Problems and Issues ===
What issues do you have with "Real Time"?

* The primary issue that I have with the real-time patch is why its still a patch and not in mainline. We seem to be asymptotically approaching inclusion. But as with any asymptote, you never seem to reach zero. TG and SR and others are working to keep the patch caught up with reasonably recent kernels, but that's a lot of work that detracts from making further progress on the core issues of determinism in Linux.

What are some possible solutions?

* The best thing would be to finally round the corner on the inclusion of the real-time patch into mainline. I realize that there differing views on the future of Linux. But, since the RT patch has seemingly minimal impact on mainline if it's not enabled, maybe 2013 will be the year that it finally makes mainline? One can only hope.

What's going on in the wider community to address these issues?

* Stephen Rostedt had a good presentation on the RT patch and where it stands in his mind. Check out his presentation from the conference. There are many of us who use the RT patch on our systems. But, it's unclear to many of us who don't follow the LKML daily as to what progress is being made in the kernel community. Can anyone enlighten the rest of us?

== People ==
Who at ELC is interested in "Real Time"?

* Frank Rowand
* Tim Bird
* Mike Anderson

== Presentation notes ==
What presentations at ELC, on the subject of "Real Time" did people like? Why?

Put your notes about the "Real Time" presentations from ELC here...

=== Presentations ===

* Wed 2/20 Frank Rowand '''Using and Understanding the Real-Time Cyclictest Benchmark'''
** A conceptual description of the cyclictest algorithm
** How to use cyclictest to understand the real time latency of your system
** What does cyclictest data typically look like for different architectures?
** cyclictest options are very powerful and must be selected with care
** There are several different formats of data, which provide different views of system behavior
** There are debug options to help investigate causes of large latencies
* Wed 2/20 Steven Rostedt '''Understanding PREEMPT-RT (The Real-Time Patch)'''
** Steven is the Stable RT Branches maintainer
** The math of trebuchets
** The technology in the PREEMPT_RT Linux kernel that enable real time
** Current issues that are being worked on
* Wed 2/20 Brent Roman '''Making Linux Do Hard Real-Time'''
** An experience of how PREEMPT_RT Linux is used in a scientific context
* Thu 2/21 Yoshitake Kobayashi '''Deadline Miss Detection with SCHED_DEADLINE'''
** The deadline scheduler...

=== Presentations that incidentally touched on real time ===

* Thu 2/21 Robert Rose '''Keynote: SpaceX | Moore's Law to Mars'''
* The space vehicles use PREEMPT_RT Linux
* Fri 2/22 Mathieu Poirier '''In Kernel Switcher: A Solution to Suppport ARM's New big, LITTLE Implementation'''
* Power saving and real time are like oil and water. Real time is not yet a consideration in the big, LITTLE world.
* Fri 2/22 Gregoire Gentil '''Lessons Learned In Designing a Self-Video Self-Hovering Nano Copter'''
* PREEMPT_RT is one scheduling solution that was explored

[[Category:ELC]]
[[Category:2013]]
[[Category:Tech Zone]]

Real Time Tech Zone 2013

2013-02-22T22:25:33Z

Frowand: /* Presentations that incidentally touched on real time */

Real Time Tech Zone 2013

2013-02-22T22:25:13Z

Frowand: /* Presentations */

Real Time Tech Zone 2013

2013-02-22T22:24:18Z

Frowand: /* Presentation notes */

Tech Zones

2013-02-13T23:53:43Z

Frowand: remove Test Portal

== ELC 2013 Tech Zones Contest ==

For ELC 2013's traditional wiki editing contest, participants are encouraged to contribute to the section of the wiki that
best corresponds to their specific presentation given, or to a presentation attended. Here's how:

These pages are dedicated to preserving information and discussions about specific topic areas from the Embedded Linux Conference. You should think of these pages like "scratchpads" to record your thoughts and discussions from the conference. Most of us take notes at an event, at a talk that interests us, or after we learn something new and useful from another attendee. Here's a place to record those notes in public, so that not only you can access them after the event, but everyone else can as well.

[edit]
# [[Special:UserLogin | Login]] or [[Special:RequestAccount | Request an Account]] to the wiki. Account Requests are being monitored in real time throughout the conference and will be approved immediately. If you get impatient, find [[User:Wmat | Bill Traynor]] and nag him a little.
# From this page, select the Tech Zone icon that you'd like to contribute to, either as a presenter or as an interested party.
# At the top of each Tech Zone page you'll find a section entitled '''ELC2013 Tech Zone Contest'''. Edit this section and either create a wikilink to your new page, or click through to a page already created and contribute appropriately.
# For Tech Zone discussions, add material to the Discussions section on the page. To record notes about a presentation, put those in the appropriate section of the page as well.

== ELC 2013 Tech Zones ==
{| width="100%"
|-
|style="vertical-align:top" |
<div style="margin: 0; margin-top:10px; margin-right:10px; padding: 0 1em 1em 1em; align:right;">
<div style="margin-left: 25px;">

{|style="width: 100%; margin:0; padding:0; border-collapse: collapse;"
| style="width: 25%;" |[[image:clockface.jpg|link=Real Time Tech Zone 2013]] [[Real Time Tech Zone 2013|Real Time Tech Zone]]
| style="width: 25%;" | [[image:Welly1.jpg|link=Boot Time Tech Zone 2013]] [[Boot Time Tech Zone 2013|Boot Time Tech Zone]]
| style="width: 25%;" | [[image:Padlock2.jpg|link=Security Tech Zone 2013]] [[Security Tech Zone 2013|Security Tech Zone]]
| style="width: 25%;" | [[image:Power.png|link=Power Management Tech Zone 2013]] [[Power Management Tech Zone 2013|Power Management Tech Zone]]
|-
| style="width: 25%;" | [[image:Multimedia.png|link=Multimedia Tech Zone 2013]] [[Multimedia Tech Zone 2013|Multimedia Tech Zone]]
| style="width: 25%;" | [[image:Blimp.jpg|link=System Size Tech Zone 2013]] [[System Size Tech Zone 2013|System Size Tech Zone]]
| style="width: 25%;" | [[image:Filecab.jpg|link=File Systems Tech Zone 2013]] [[File Systems Tech Zone 2013|File Systems Tech Zone]]
| style="width: 25%;" | [[image:Icon-network.png|link=Networking Tech Zone 2013]] [[Networking Tech Zone 2013|Networking Tech Zone]]
| <br />
|}

</div>
</div>

== Prizes ==

All prizes will be awarded at the closing ceremonies. You do not have to be present to win, however make sure you have a valid email address associated to your wiki account so the [[User:Wmat | Administrator]] can track you down to deliver the prize at a later date.

===First Prize===
'''Sony Digital Camera'''
===Secondary Prizes===
'''LWN gift certificates'''

Tech Zones

2013-02-13T23:53:15Z

Frowand: /* Test portal */

Real Time Tech Zone 2013

2013-02-13T23:49:59Z

Frowand: /* People */

Japan Technical Jamboree 42

2012-09-19T23:52:08Z

Frowand: /* Agenda */

{| cellpadding="0" cellspacing="0" border="0"
|-
|[[Image:HeadTitle.gif]]
|-
| style="text-align:right" |<span style="font-size:large">Date: September 20th/ 日付: 9月20日（'''木'''）</span>
* At Nakano Sunplaza / 於、中野サンプラザ
* Please join "celinux-dev" mailinglist to get the latest announcement.
* "celinux-dev" メーリングリストにこのイベント関係のアナウンスが流れます。ぜひ参加してください。
** [http://lists.celinuxforum.org/mailman/listinfo/celinux-dev How to join.]

|-
|[[Image:J_Jam_SessionProp.gif]]
|-
|style="text-align:right" |[[Japan TJ Session Proposal|<span style="color:red">Session proposal how-to. / 提案の方法</span>]]
|}
= Introduction / はじめに =
* The Japan Technical Jamboree is a forum-wide technical meeting of the CE Workgroup of the Linux Foundation. This meeting will be located conveniently in Japan and use Japanese as the native language of the event.
* A general guidance page is available. / 初めての方はこちらもお読みください。
** [http://tree.celinuxforum.org/CelfPubWiki/JapanTechnicalJamboreeGuidance JapanTechnicalJamboreeGuidance] (Japanese/English)
== Special remarks for non Japanese speakers ==
* This page is Japanese/English bilingual. Please allow some contents on this page are not translated into English because of this event is Japan regional one, though we try to place English translation.
* If you would like to perform your presentation in English, we also welcome you to join! We hope you to speak slowly without any complicated expressions. Most Japanese developers are capable to understand plain English.
== Previous Jamboree ==
* Please look into the wiki page. / 下記のWikiページをご覧ください。
** [[Japan Technical Jamboree 41]]

= Date and venue... / 日付・場所... =
{|
|+
|-
| style="vertical-align:top" |
[[Image:Nakano Sunplaza.jpg]]
| style="vertical-align:top; background-color:#F0F0F0" width=90% |
* Date '''September 20th, 2012'''
** '''Starting at 10 am'''
* At '''''Nakano Sunplaza / 8F Training Room 2''''' / 会場 '''''中野サンプラザ / 8階・研修室２'''''
** Nakano Sunplaza is located just close to '''Nakano''' station (JR/Tokyo Metoro ).
** http://www.sunplaza.jp/ (Japanese)
* Admission: '''''Free of charge''''' / 参加費用: '''''無料'''''
* Not limited for CELF members. / CELF会員以外も参加・セッション持ち込み共に可能
* Coordinators / 世話役 (Your inquiries in English welcome)
** Hisao Munakata / 宗像尚郎 (hisao_dot_munakata_dot_vt(a)renesas_dot_com)
** Satoru Ueda / 上田理 (Satoru_dot_Ueda(a)jp_dot_sony_dot_com)
|}
== Registration / 参加登録 ==
* No registration required / 参加登録は要りません。

= Main Topics =
* It is just after the Kernel Summit and final Jamboree before ELC Europe.

= Agenda / 進行 =
== Agenda ==

{|
|+
! style="text-align:left; background-color:#B0FFB0; width:50" | Time
! style="text-align:left; background-color:#B0FFB0; width:70%" | Title and presenter
! style="text-align:left; background-color:#B0FFB0" | Notes
Presentation Materials
|-
| style="vertical-align:top; background-color:#F0F0F0" | 10:00..
| style="vertical-align:top; background-color:#F0F0F0" |
* Opening / 連絡事項
| style="vertical-align:top; background-color:#F0F0F0" |

|-
| style="vertical-align:top; background-color:#F0F0F0" | 10:15am..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Embedded Linux status update'''
* '''Tim Bird''' (Connect from USA)
** Latest Community topics update - quick update.
** Latest CE WG project updates
| style="vertical-align:top; background-color:#F0F0F0" |
(In English / 英語のセッションです)
|-
| style="vertical-align:top; background-color:#F0F0F0" | 12:00..
| style="vertical-align:top; background-color:#F0F0F0" |
Lunch
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 1:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Status of Linux 3.x Realtime and Changes From 2.6'''
* '''Frank Rowand''' (Connect from USA)
| style="vertical-align:top; background-color:#F0F0F0" |
(In English / 英語のセッションです)
https://events.linuxfoundation.org/events/linuxcon-japan/rowand
* [[File:Status_of_real_time.pdf]]
|-
| style="vertical-align:top; background-color:#F0F0F0" | 2:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''The latest status of LTSI project'''
* '''S. Ueda''' (On behalf of Shibata san and Munakata san)
| style="vertical-align:top; background-color:#F0F0F0" |
* [[File:Ltsi2012lcna.pdf]]‎
|-
| style="vertical-align:top; background-color:#F0F0F0" | 2:30pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''コミュニティーデビューの体験をゆる～く'''
* How to post patch
* '''Tetsuyuki Kobayashi'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 3:15pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Evaluation of Flash Filesystems Update'''
* SFTL (Simple Flash Translation Layer)
* '''K. Uwatoko'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 4:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Developing Embedded Linux by Poky'''
* '''K.Hayashi''', TOSHIBA
* ビルドシステムPokyを使用して、オリジナルのLinux環境を構築する方法についてご説明します
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 4:45pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''A little complicated issue / Legal Complianse'''
* Introduction of Open Compliance Summit
* '''S. Ueda'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 5:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
* '''''Calling for your session proposals'''''
| style="vertical-align:top; background-color:#F0F0F0" |
* [[Japan TJ Session Proposal|<span style="color:red">Session proposal how-to. / 提案の方法</span>]]
|-
| style="vertical-align:top; background-color:#F0F0F0" | 6:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Japan OSS Promotion Forum / Embedded System Sub-Group Meeting'''
* '''S. Ueda'''
** It is the work group meeting though open to everyone to attend.
** 日本OSS推進フォーラム、組込みシステム部会のミーティングですが、どなたでも参加可能です。
| style="vertical-align:top; background-color:#F0F0F0" |
|-
|}

* Please be noted above time table is just a guideline and may be shifted. / 上記の時間割は目安です。かなり前後する可能性がありますので、あらかじめご承知おきください。

== Special Remarks ==
* Please place some detail descriptions about each presentation topics.
: こちらに各プレゼンテーションの詳細などを記載してください。

= Ask for your help / お願い =
== Presentation Materials ==
* We wish you to prepare the materials in English. / 出来るだけプレゼンテーション資料は英語で表記してください。絶対ではありませんが、日本語が理解できない方に対しての配慮が出来ればと思います。
* Please leave your material in this wiki site after the event. / ジャンボリー終了後、プレゼンテーション資料はこのWikiに残してください。
== English Translation Volunteer ==
* If you can help the translation volunteer from Japanese to English, we would be very much appreciated! / 日本語を英訳していただくボランティアを大歓迎します！

[[Category:Japan Technical Jamboree]]
[[Category:Events]]

Japan Technical Jamboree 42

2012-09-19T04:26:46Z

Frowand: /* Agenda */

{| cellpadding="0" cellspacing="0" border="0"
|-
|[[Image:HeadTitle.gif]]
|-
| style="text-align:right" |<span style="font-size:large">Date: September 20th/ 日付: 9月20日（'''木'''）</span>
* At Nakano Sunplaza / 於、中野サンプラザ
* Please join "celinux-dev" mailinglist to get the latest announcement.
* "celinux-dev" メーリングリストにこのイベント関係のアナウンスが流れます。ぜひ参加してください。
** [http://lists.celinuxforum.org/mailman/listinfo/celinux-dev How to join.]

|-
|[[Image:J_Jam_SessionProp.gif]]
|-
|style="text-align:right" |[[Japan TJ Session Proposal|<span style="color:red">Session proposal how-to. / 提案の方法</span>]]
|}
= Introduction / はじめに =
* The Japan Technical Jamboree is a forum-wide technical meeting of the CE Workgroup of the Linux Foundation. This meeting will be located conveniently in Japan and use Japanese as the native language of the event.
* A general guidance page is available. / 初めての方はこちらもお読みください。
** [http://tree.celinuxforum.org/CelfPubWiki/JapanTechnicalJamboreeGuidance JapanTechnicalJamboreeGuidance] (Japanese/English)
== Special remarks for non Japanese speakers ==
* This page is Japanese/English bilingual. Please allow some contents on this page are not translated into English because of this event is Japan regional one, though we try to place English translation.
* If you would like to perform your presentation in English, we also welcome you to join! We hope you to speak slowly without any complicated expressions. Most Japanese developers are capable to understand plain English.
== Previous Jamboree ==
* Please look into the wiki page. / 下記のWikiページをご覧ください。
** [[Japan Technical Jamboree 41]]

= Date and venue... / 日付・場所... =
{|
|+
|-
| style="vertical-align:top" |
[[Image:Nakano Sunplaza.jpg]]
| style="vertical-align:top; background-color:#F0F0F0" width=90% |
* Date '''September 20th, 2012'''
** '''Starting at 10 am'''
* At '''''Nakano Sunplaza / 8F Training Room 2''''' / 会場 '''''中野サンプラザ / 8階・研修室２'''''
** Nakano Sunplaza is located just close to '''Nakano''' station (JR/Tokyo Metoro ).
** http://www.sunplaza.jp/ (Japanese)
* Admission: '''''Free of charge''''' / 参加費用: '''''無料'''''
* Not limited for CELF members. / CELF会員以外も参加・セッション持ち込み共に可能
* Coordinators / 世話役 (Your inquiries in English welcome)
** Hisao Munakata / 宗像尚郎 (hisao_dot_munakata_dot_vt(a)renesas_dot_com)
** Satoru Ueda / 上田理 (Satoru_dot_Ueda(a)jp_dot_sony_dot_com)
|}
== Registration / 参加登録 ==
* No registration required / 参加登録は要りません。

= Main Topics =
* It is just after the Kernel Summit and final Jamboree before ELC Europe.

= Agenda / 進行 =
== Agenda ==

{|
|+
! style="text-align:left; background-color:#B0FFB0; width:50" | Time
! style="text-align:left; background-color:#B0FFB0; width:70%" | Title and presenter
! style="text-align:left; background-color:#B0FFB0" | Notes
Presentation Materials
|-
| style="vertical-align:top; background-color:#F0F0F0" | 10:00..
| style="vertical-align:top; background-color:#F0F0F0" |
* Opening / 連絡事項
| style="vertical-align:top; background-color:#F0F0F0" |

|-
| style="vertical-align:top; background-color:#F0F0F0" | 10:15am..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Embedded Linux status update'''
* '''Tim Bird''' (Connect from USA)
** Latest Community topics update - quick update.
** Latest CE WG project updates
| style="vertical-align:top; background-color:#F0F0F0" |
(In English / 英語のセッションです)
|-
| style="vertical-align:top; background-color:#F0F0F0" | 12:00..
| style="vertical-align:top; background-color:#F0F0F0" |
Lunch
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 1:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Status of Linux 3.x Realtime and Changes From 2.6'''
* '''Frank Rowand''' (Connect from USA)
| style="vertical-align:top; background-color:#F0F0F0" |
(In English / 英語のセッションです)
https://events.linuxfoundation.org/events/linuxcon-japan/rowand
[[File:Status_of_real_time.pdf]]
|-
| style="vertical-align:top; background-color:#F0F0F0" | 2:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''The latest status of LTSI project'''
* '''S. Ueda''' (On behalf of Shibata san and Munakata san)
| style="vertical-align:top; background-color:#F0F0F0" |
* [[File:Ltsi2012lcna.pdf]]‎
|-
| style="vertical-align:top; background-color:#F0F0F0" | 2:30pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''コミュニティーデビューの体験をゆる～く'''
* How to post patch
* '''Tetsuyuki Kobayashi'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 3:15pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Evaluation of Flash Filesystems Update'''
* SFTL (Simple Flash Translation Layer)
* '''K. Uwatoko'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 4:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Developing Embedded Linux by Poky'''
* '''K.Hayashi''', TOSHIBA
* ビルドシステムPokyを使用して、オリジナルのLinux環境を構築する方法についてご説明します
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 4:45pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''A little complicated issue / Legal Complianse'''
* Introduction of Open Compliance Summit
* '''S. Ueda'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 5:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
* '''''Calling for your session proposals'''''
| style="vertical-align:top; background-color:#F0F0F0" |
* [[Japan TJ Session Proposal|<span style="color:red">Session proposal how-to. / 提案の方法</span>]]
|-
| style="vertical-align:top; background-color:#F0F0F0" | 6:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Japan OSS Promotion Forum / Embedded System Sub-Group Meeting'''
* '''S. Ueda'''
** It is the work group meeting though open to everyone to attend.
** 日本OSS推進フォーラム、組込みシステム部会のミーティングですが、どなたでも参加可能です。
| style="vertical-align:top; background-color:#F0F0F0" |
|-
|}

* Please be noted above time table is just a guideline and may be shifted. / 上記の時間割は目安です。かなり前後する可能性がありますので、あらかじめご承知おきください。

== Special Remarks ==
* Please place some detail descriptions about each presentation topics.
: こちらに各プレゼンテーションの詳細などを記載してください。

= Ask for your help / お願い =
== Presentation Materials ==
* We wish you to prepare the materials in English. / 出来るだけプレゼンテーション資料は英語で表記してください。絶対ではありませんが、日本語が理解できない方に対しての配慮が出来ればと思います。
* Please leave your material in this wiki site after the event. / ジャンボリー終了後、プレゼンテーション資料はこのWikiに残してください。
== English Translation Volunteer ==
* If you can help the translation volunteer from Japanese to English, we would be very much appreciated! / 日本語を英訳していただくボランティアを大歓迎します！

[[Category:Japan Technical Jamboree]]
[[Category:Events]]

File:Status of real time.pdf

2012-09-19T04:23:02Z

Frowand:

ELC 2012 Presentations

2012-09-04T22:05:28Z

Frowand: /* Presenters */

Presenters, Demo-ers, Participants:
Thanks very much for your participation in Linux Foundation's [https://events.linuxfoundation.org/events/embedded-linux-conference Embedded Linux Conference 2012].

This page is for collecting the presentations that were made at the conference. During and
after the conference we will collect materials from the presenters and place them here.
Please watch this page if you are interested in a particular presentation - and if it
doesn't show up, please [[Special:EmailUser/Wmat | send me and email]] and we'll try to track it down.

== Videos ==

Videos for ELC2012 from the Linux Foundation can be found at [http://video.linux.com/categories/2012-embedded-linux-conference ELC2012 Videos]. Free Electrons also took video recordings of the talks, and plans to make them available shortly.

In addition to the latter, Free Electrons has also provided video of Andoid builders Summit talks, and ELC talks:

[http://free-electrons.com/blog/abs-2012-videos/ Android Builders Summit]<br/>
[http://free-electrons.com/blog/elc-2012-videos/ ELC]

== Instructions ==
'''Presenters:''' Please post your technical conference presentations on this page.
(See Instructions below the tables)

= Table of Presentations =

NOTE: If you add a wikilink to your presentation and attempt to upload it via the link, it may fail. If it does, use the [[Special:Upload]] page to upload your file.

== Keynotes ==
{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Keynotes'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
| Jon Corbett, Editor at LWN.net
| The Kernel Report
| [[Media:lf_elc12_corbet.pdf | The Kernel Report ELC2012]]
|-
| Mike Anderson, CTO at The PTR Group
| The Internet of Things
| [[Media:anderson.pdf | The Internet of Things]]
|}

<br />

== Presenters ==
{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Presentations'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 1, 9:30am
|-
| Loïc Pallardy
| Saving the Power Consumption of the Unused Memory
| [[Media:lf_elc12_pallardy.pdf|PDF]]
|-
| Bernhard Rosenkränzer, Linaro
| What Android and Embedded Linux Can Learn From Each Other
| [[Media:lf_elc12_rosenkranzer.pdf|PDF]]
|-
| Ricardo Salveti de Araujo, Linaro
| Ubuntu on ARM: Improvements and Optimizations Done By Linaro
| [[Media:Ubuntu_on_ARM-_Improvements_and_Optimizations_Done_By_Linaro.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 1, 11:30am
|-
| Zach Pfeffer, Linaro
| Binary Blobs Attack
| [[Media:lf_elc12_pfeffer.pdf|PDF]]
|-
| Hisao Munakata, Renesas Electronics
| Close Encounters of the Upstream Resource
| [[Media:lf_elc12_munakata.pdf|PDF]]
|-
| Daniel Hursh, IBM
| Open Source Automated Test Framework
| [[Media:lf_elc12_hursh.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 1, 2:00pm
|-
| Saul Wold, Intel
| The Yocto Project Overview and Update
| [[Media:The Yocto Project Overview and Update.pdf|PDF]]
|-
| Sean Hudson, Mentor Graphics, Inc.
| Embedded Linux Pitfalls
| [[Media:Embedded Linux Pitfalls.pdf|PDF]]
|-
| Vincent Guittot, Linaro
| Comparing Power Saving Techniques For Multicore ARM Platforms
| [[Media:Comparing Power Saving Techniques For Multicore ARM Platforms.pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 1, 3:00pm
|-
|-
| Tim Bird, Sony Network Entertainment
| Status of Embedded Linux
| [[Media:Status-of-embedded-Linux-2012-02-ELC-v2.pdf|PDF]]
|-
| Bruce Ashfield, Wind River
| A View From the Trenches: Embedded Functionality and How It Impacts Multi-Arch Kernel Maintenance
| [[Media:A_View_From_the_Trenches-_Embedded_Functionality_and_How_It_Impacts_Multi-Arch_Kernel_Maintenance.pdf‎|PDF]]
|-
| R Durgadoss, Intel
| PeakCurrent Management in x86-Based Smartphones
| [[Media:PeakCurrent Management in x86-Based Smartphones.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 1, 4:15pm
|-
| Matt Porter, Texas Instruments
| Passing Time With SPI Framebuffer Driver
| [[Media:Passing Time With SPI Framebuffer Driver.pdf|PDF]]
|-
| Wookey, Linaro
| Multiarch and Why You Should Care: Running, Installing and Crossbuilding With Multiple Architectures
| [[Media:Multiarch_and_Why_You_Should_Care-_Running,_Installing_and_Crossbuilding_With_Multiple_Architectures.pdf|PDF]] [[Media:SourceCode.tgz|SOURCE]]
|-
| Amit Daniel Kachhap, Linaro/Samsung
| A New Simplified Thermal Framework For ARM Platforms
| [[Media:A New Simplified Thermal Framework For ARM Platforms.pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 1, 5:15pm
|-
|-
| Tsugikazu Shibata, NEC
| On The Road: To Provide the Long-Term Stable Linux For The Industry
| [[media:On_The_Road-_To_Provide_the_Long-Term_Stable_Linux_For_The_Industry.pdf|PDF]]
|-
| Thomas P. Abraham, Samsung Electronics
| Experiences With Device Tree Support Development For ARM-Based SOC's
| [[Media:Experiences With Device Tree Support Development For ARM-Based SOC's.pdf|PDF]]
|-
| Paul E. McKenney, IBM
| Making RCU Safe For Battery-Powered Devices
| [[media:Making RCU Safe For Battery-Powered Devices.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 2, 10:30am
|-
| Thomas Petazzoni, Free Electrons
| Buildroot: A Nice, Simple, and Efficient Embedded Linux Build System
| [[Media:Buildroot2.pdf|PDF]]
|-
| Steven Rostedt, Red Hat
| Automated Testing with ktest.pl (Embedded Edition)
| [[Media: Automated Testing with ktest.pl (Embedded Edition).pdf|PDF]]
|-
| David VomLehn, Cisco
| Intricacies of a MIPS Stack Backtrace Implementation
| [[Media:Intricacies of a MIPS Stack Backtrace Implementation.pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 2, 11:30am
|-
| Edward Hervey, Collabora
| GStreamer 1.0: No Longer Compromise Flexibility For Performance
| [[Media:GStreamer_1.0-_No_Longer_Compromise_Flexibility_For_Performance.pdf|PDF]]
|-
| Steven Rostedt, Red Hat
| Automated Testing with ktest.pl (Embedded Edition) (Cont.)
| [[Media: Automated Testing with ktest.pl (Embedded Edition).pdf|PDF]]
|-
| Tim Bird, Sony Network Entertainment
| Embedded-Appropriate Crash Handling in Linux
| [[Media:Embedded-Appropriate Crash Handling in Linux.pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 2, 2:00pm
|-
| Arnd Bergmann, Linaro
| ARM Subarchitecture Status
| [[Media:ARM Subarchitecture Status.pdf|PDF]]
|-
| Mark Gisi, Wind River Systems
| The Power of SPDX - Sharing Critical Licensing Information Within a Linux Device Supply Chain
| [[Media:The Power of SPDX - Sharing Critical Licensing Information Within a Linux Device Supply Chain.pdf|PDF]]
|-
| Yoshitake Kobayashi, Toshiba
| Ineffective and Effective Ways To Find Out Latency Bottlenecks With Ftrace
| [[Media:Ineffective and Effective Ways To Find Out Latency Bottlenecks With Ftrace.pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 2, 3:00pm
|-
| Ohad Ben-Cohen, Wizery / Texas Instruments
| Using virtio to Talk With Remote Processors
| [[Media:Using virtio to Talk With Remote Processors.pdf|PDF]]
|-
| Elizabeth Flanagan, Intel
| Embedded License Compliance Patterns and Antipatterns
| [[Media:Embedded License Compliance Patterns and Antipatterns.pdf|PDF]]
|-
| David Anders, Texas Instruments
| Board Bringup: LCD and Display Interfaces
| [[elc-lcd|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 2, 4:15pm
|-
| Rob Clark, Texas Instruments
| DMA Buffer Sharing: An Introduction
| [[Media:DMA_Buffer_Sharing-_An_Introduction.pdf|PDF]]
|-
| Ken Tough, Intrinsyc
| Linux on eMMC: Optimizing For Performance
| [[Media:Linux_on_eMMC-_Optimizing_For_Performance.pdf|PDF]]
|-
| Paul Larson, Linaro
| LAVA Project Update
| [[Media:LAVA Project Update.pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 2, 5:15pm
|-
| Jeff Osier-Mixon, Intel
| Yocto Project Community (BoFs)
| No Slides
|-
| Frank Rowand, Sony Network Entertainment
| Real Time (BoFs)
| [[Media:Real Time (BoFs).pdf|PDF]]
|-
| Mike Turquette, Texas Instruments
| Common Clock Framework (BoFs)
| [[Media:Common Clock Framework (BoFs).pdf|PDF]]
|-
|- bgcolor="#a0c0c0"
| colspan="3" | Day 3, 9:00am
|-
| Hunyue Yau, HY Research LLC
| Userland Tools and Techniques For Linux Board Bring-Up and Systems Integration
| [[Media:Userland Tools and Techniques For Linux Board Bring-Up and Systems Integration.pdf|PDF]]
|-
| Matt Weber, Rockwell Collins Inc.
| Optimizing the Embedded Platform Using OpenCV
| [[Media:Optimizing the Embedded Platform Using OpenCV.pdf|PDF]]
|-
| Greg Ungerer, McAfee
| M68K: Life in the Old Architecture
| [[Media:M68K-_Life_in_the_Old_Architecture.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 3, 10:00am
|-
| Gary Bisson, Adeneo Embedded
| Useful USB Gadgets on Linux
| [[Media:Useful USB Gadgets on Linux.pdf|PDF]]
|-
| Jason Kridner, Texas Instruments
| GUIs: Coming To Uncommon Goods Near You
| [[Media:Guis_coming_to_uncommon_goods.pdf|PDF]]
|-
| Mike Anderson, The PTR Group
| Adapting Your Network Code For IPv6 Support
| [[Media:Adapting Your Network Code For IPv6 Support.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 3,11:30pm
|-
| Koen Kooi, The Angstrom Distribution
| Producing the Beaglebone and Supporting It
| No Paper - see video
|-
| Danny Bennett, basysKom GmbH
| HTML5 in a Plasma-Active World
| [[Media:HTML5 in a Plasma-Active World.pdf|PDF]]
|-
| Marcin Mielczarczyk, Tieto
| Getting the First Open Source GSM Stack in Linux
| [[Media:Getting the First Open Source GSM Stack in Linux.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 3, 2:00pm
|-
|-
| Pierre Tardy, Intel
| PyTimechart Practical
|[[Media:PyTimechart Practical.pdf|PDF]]
|-
| Linus Walleij, ST-Ericsson
| Pin Control Subsystem Overview
| [[Media:Pin Control Subsystem Overview.pdf|PDF]]
|-
| Khem Raj, OpenEmbedded Project
| OpenEmbedded - A Layered Approach
| [[Media:OpenEmbedded - A Layered Approach.pdf|PDF]]
|- bgcolor="#a0c0c0"
| colspan="3" | Day 3, 3:00pm
|-
| Lucas De Marchi, ProFUSION Embedded Systems
| Managing Kernel Modules With kmod
| [[Media:Managing Kernel Modules With kmod.pdf|PDF]]
|-
| Jean Pihet, NewOldBits
| A New Model for the System and Devices Latency
| [[Media:A New Model for the System and Devices Latency.pdf|PDF]]
|-
| Pintu Kumar, Samsung
| Controlling Linux Memory Fragmentation and Higher Order Allocation Failure: Analysis, Observations and Results
| [[Media:Controlling_Linux_Memory_Fragmentation_and_Higher_Order_Allocation_Failure-_Analysis,_Observations_and_Results.pdf|PDF]]
|}

<br />

== Workshops ==
{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Workshops'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|-
| Karim J. Yaghmour
| Embedded Android Workshop
| [[Media:Android Workshop.pdf|PDF]]
|-

|}

<br />

== Instructions for Presenters ==
Please create a link in the table for your presentation, copying the style of other links.
(You may need to create an account in order to edit the wiki or upload files.)

When you have created the link, click on it to upload the file containing your slides.
[[Category:ELC]]
[[Category:2012]]
[[Category:Events]]
[[Category:Presentations]]

Mainline Android logger project

2012-03-26T19:38:47Z

Frowand: /* [8] ttyprintk driver */

This page is for managing information related to the "Mainline Android Logger" project
of the CE Workgroup. This is part of the [[Android Mainlining Project]].

== Android logger issues ==
This section describes some attributes of the Android logger code, which are
relevant for mainlining the code into Linux. Let's use a modified SWOT (Strengths,
Weaknesses, Opportunities, Threats) analysis for strategic planning to mainline
this code.

To find the logger's strengths and weaknesses, lets research and provide information
and hard numbers for how it compares with existing logging alternatives.

=== Alternatives ===
What are the alternatives to the Android logger?
* logbuf (the kernel log buffer)
** apparently, systemd uses this
* syslog
* "the journal" - a new logging system for systemd (by Lennart Poettering)
** see [https://docs.google.com/document/pub?id=1IC9yOXj7j6cdLLxWEBAGRL6wl97tFxgjLUEHIX3MSTs&pli=1 systemd journal] for a good discussion of problems with syslog
* Neil Brown's log-pipe idea
** I thought this one was interesting. See: [http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/02484.html Neil Brown's message about this on LKML]
* Arnd Bergmann's tmpfs idea
** See [http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/02737.html this message]

What are the pros and cons of each system (see feature matrix below)

=== Existence ===
Does the system or proposed alternative currently exist?

How much work would it be to create it?

How much work would it be to test it to confirm that it had the same semantics as current Android logger?

=== Performance ===
How much overhead does each logging system have?

How long does it take to write 1 million messages, for each of the above systems?

How many context switches are required to log a single message?

How long is each message, on average?

How many data copies are performed for each message?

What is the average time to write each message, from the caller's perspective?

=== Size ===
What are the space requirements for each logging system?

what is the code footprint in the kernel?

What is the data footprint in the kernel?

What is the code footprint in user-space?

What is the data footprint in user-space?

Are any other modules are required solely to support logging?

What is the size required in persistent storage?

Can the size be limited (at compile-time?, at boot-time?, at run-time?)

Can the size be adjusted (at boot-time?, at run-time?)

Given default sizes, and expected logging rates, how much time does each system record?

=== Maintainability ===
How much does each system need to be maintained?

How many changes have been made to the each system in the last 3 years?

Are any significant changes expected in the future?

=== Configurability ===
What things can be configured at compile-time and run-time for each system?

=== Features ===
What features does each of the log systems have?

{| border="1" cellspacing="0" cellpadding="5"
|-bgcolor="#80c0d0"
!Attribute!!logger!!logbuf!!syslog!!Notes
|-
|multiple channels||yes||no||no?||allows for separation of data to prevent overrun
|-
|can limit space used||yes||yes||?||
|-
|cost to write 1M messages||?||?||?||need to benchmark
|-
|average cost to write a message||?||?||?||need to measure
|-
|average message size||?||?||?||need to measure
|-
|RAM required for complete logger system||?||?||?||need to measure (should include code space)
|-
|amount of flash or disk required for complete logger system||?||?||?||need to measure (should include code space)
|-
|user daemon required?||no||no||yes||syslog requires syslogd
|-
|networking required||no||no||no*||syslog requires network for some remote features
|-
|number of context switches per message||?||?||?||need to measure
|-
|logs both kernel and user messages?||no||no||yes?||klogd puts logbuf messages into syslog?
|-
|ability to store messages persistently on target||no||no*||yes||klogd puts logbuf messages into syslog?
|-
|ability to store messages persistently on host||yes*||no||yes
|
* adb logcat is builtin command for android
* you can use 'remote shell:dmesg >log.txt' on most embedded systems, but it's not really a design principle of logbuf
* syslog is built with remote message access integrated into the system
|-
|integrated into existing debug tools||yes||no?||no?||I don't know of anything but target-side tools (dmesg, cat /var/log) that "know" about logbuf and syslog
|-
|ability to filter messages by tag||yes||no||?||does syslog require tagging, is grep used for syslog tagging?
|-
|ease of use||high||low ||medium
|
* Android has facilities for logging available throughout the system (CLI, C/C++, Java), as well as good tool integration for readout and filtering
* klogd has 'echo >/dev/kmsg', but nothing else integrated into user-space stack
* syslog has logger, and libc calls (openlog, syslog, closelog)
|-
|tool support
|toolbox, adb
|busybox, standalone dmesg, klogd
|busybox, standalone logger, syslogd
|
|-
|API stability
|high*
|high
|high
|One change, to add 'system' channel in Android, in last 3 years. System channel separates system log messages from application log messages to prevent buffer exhaustion in case of a chatty application.
|}

=== Extension questions ===
Here are some questions about how the systems could be integrated:

* What features ''could'' each log system have, if extended?
* Would extension to an existing system interfere with it's current primary purpose?
* For each change contemplated, can it be implemented to minimize the impact to existing code?

=== Barriers to entry as is (Weaknesses) ===
Does logger duplicate functionality that exists elsewhere?
Does it make sense to extend an existing system, rather than implement a new system?

What are barriers to entry:
* use of ioctl?
* hardcoded number of log channels
* other style issues?
* longterm maintainer?

=== Attractive features of logger as is (Strengths) ===
What are the differentiating features of logger, compared to alternatives?

* minimal context switches for logging
* use of ring buffer automatically limits log size
* log is in memory (no cost to store unused log messages)
* all messages are tagged
* all messages have priority
* all messages have timestamp
* user-space program to filter messages by tag
* channel selection by user-space policy

== Discussions ==
This section has notes about discussions with the community kernel developers and with Google engineers,
with regards to mainlining this code

=== Google engineer requests/questions ===
* Google doesn't want to change their class libraries or debug system
** These have already shipped to developers and are integrated into other tools (eclipse log viewer)
** the Android system and over 200,000 applications already use the existing classes
** (So, can changes be made "under the hood" without changing the existing user interface?)

* Google requests that any changes submitted to mainline also be placed in their kernel repository (or Gerrit review queue), so they can see them when they do merges and are not caught off guard.
** I'm not sure the detailed steps required to perform this

* Question: Why did Google write their own code, instead of using syslog?
** Was it simply expedience, lack of familiarity with syslog, or are there specific reasons they wrote a new system (missing features, etc.)?

=== Community feedback/input/questions ===
* Greg KH - [http://driverdev.linuxdriverproject.org/pipermail/devel/2011-May/016658.html "At worse case, all of the code could go away and the normal logging interface be used, after it would be fixed up to handle the special needs that warranted the creation of the android logger code in the first place."]

* Alessio - In my opinion syslog shouldn't be compared with neither Android's logger nor logbuf because:
# Buggy syslog implementation (or future changes) could shutdown the entire log infrastructure (logger and logbuf aren't supposed to change a lot in future)
# Logbuf and logger don't require writeable file system access which is mandatory for syslog. A no-writeable files-system (or a file-system which allow only few writes) is a common situation in embedded world.
# Logbuf and logger don't require maintenance work (no rotate, compress or purge old log files). A mandatory feature in consumer devices.
The advantages of logger over logbuf are:
# Logger's logs are shared among a unknown number of user space programs
# <del>logbuf are writable only by kernel itself</del>
# Logger's log are separated: An wild user space program couldn't fill up all logs.
# Write path in logger is optimized over all else

=== December 2011 LKML discussion ===
Here is the thread:
* [http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/index.html#02419 on lkml.indiana.edu]
* [https://lkml.org/lkml/2011/12/21/477 on lkml.org]

Notes on specific issues:
==== [1] seems redundant with logbug/syslog(2) ====
* [1] logbuf/syslog(2) code seems to do this now (Greg KH, Kay Sievers)
** see systemd usage, which appears to coalesce stuff into /dev/kmsg
*** adding warts to logbuf doesn't seem like a great idea, it's already got realtime issues that were never solved
*** but integration with user and kernel messages could be nice
*** integration also requires some oddities
**** do you convert the log message fields (pid and priority) to structured text, and parse them out again later
**** note that systemd added support for priorities and/or tags to logbuf (Kay Seivers) see
** the ioctl for logger looks a lot like syslog(2), any way to consolidate?
*** you'd have to add channels to syslog(2), if you wanted to have separate channels

==== [2] hardcoded names and number of logs in user-space and the kernel ====
* [2] hardcoded names and number of logs in user-space and the kernel (David Brown, Neil Brown, Andrew Morton)
** no argument there (Brian Swetland)

==== [3] logbuf filesystem idea ====
* [3] logbuf filesystem idea (Neil Brown)
<pre>
If you created a 'logbuf' filesystem that used libfs to provide a single
directory in which privileged processes could create files then you wouldn't
need the kernel to "know" the allowed logs: radio, events, main, system.
The size could be set by ftruncate() (by privileged used again) rather than
being hardcoded.

You would define 'read' and 'write' much like you currently do to create a list of
datagrams in a circular buffer and replace the ioctls by more standard
interfaces:

LOGGER_GET_LOG_BUG_SIZE would use 'stat' and the st_blocks field
LOGGER_GET_LOG_LEN would use 'stat' and the st_size field
LOGGER_GET_NEXT_ENTRY_LEN could use the FIONREAD ioctl
LOGGER_FLUSH_LOG could use ftruncate
</pre>

** this fixes (2) by allowing arbitrary logs created by user space
*** unfortunately, the log channels don't exist until after user space is up a while
*** maybe could hardcode a mechanism for a default system log at startup, with other to follow
** Greg KH also asks why we need a new interface for this rather than logbuf/syslog(2)

==== [4] features, requirements and wishlist ====
* [4] features, requirements and wishlist (Brian Swetland)
** avoid hardcoding the names and sizes of the logs
** adjust permissions so that some apps can only read back their own log messages (security by pid or by channel?)
** allow logs to survive reboot
** allow an app to create it's own log, up to a specified size limit, but in a way that wouldn't
consume too much memory systemwide
<pre>
The goals behind the logger driver have been:
- keep userland and kernel logging separate (so that spammy userland
logging doesn't make us lose critical kernel logs or the other way
round)
- make log writing very inexpensive -- avoid having to pass messages
between processes (more critical on ARM9 platforms where this implied
extra cache flushing), avoid having to make several syscalls to write
a log message (getting time of day, etc), and so on
- make log writing reliable -- don't trust userland to report its
timestamp, PID, or to correctly format the datagrams, etc
- allow a log watching process (logcat) to easily pull data from all
logs at once
- avoid committing a vast amount of memory to logging
- try to prevent clients from spamming each other out of log space
(only successful on a coarse granularity right now with the
main/system/radio/events logs)
- ensure logs are not lost at the moment an app crashes
</pre>

==== [6] separate log channels are not needed ====
* [6] separate log channels are not needed or desirable (Kay Sievers)
** for early boot and debug, you want interleaving

==== [7] write cost is not a problem ====
* [7] write cost is not a problem (Kay Sievers, David Lang)
** I have no numbers, but suspect there is no problem

==== [8] ttyprintk driver ====
* [8] userspace printk tty (ttyprintk) driver (Greg KH, Kay Sievers mentioned it)
** I never heard of it - need to do some research I guess
** see linux/drivers/char/ttyprintk.c
** Feature was added in August 2010 (kernel version 2.6.36?)
** Results: ttyprintk allows user-space to submit messages to the kernel log buffer
*** ttyprintk features:
*** convert CR to LF,
*** adds '[U]' tag in front of each message
*** splits long messages into fragments no longer than 508 bytes
** (How is this different from /dev/kmsg???)
*** purpose appears to be to automatically grab messages from programs stdout that would normally be written to the system console
*** see thread about "console logging detour via printk" here: http://lkml.indiana.edu/hypermail/linux/kernel/1005.0/00009.html
*** I'm not sure how this is installed. (maybe with console=ttyprintk on the command line?)

** See http://www.kerneltrap.org/mailarchive/linux-kernel/2010/8/25/4611115 for Alan Cox's justification for this, compared to systemd on Fedora 14, or Kay Seiver's 'exec </dev/console >/dev/kmsg 2>&1'
*** '''CAUTION: 'exec </dev/console >/dev/kmsg 2>&1' crashes the Xserver on my Fedora 14 system (frowand)'''
*** answering the question - what's different about this from /dev/kmsg
*** also: http://www.kerneltrap.org/mailarchive/linux-kernel/2010/8/25/4611254
*** A user-space program can do this message transfer (see Kay's thing above), but /dev/kmsg can't be a console because it's missing some ioctls that are expected for a tty device
*** this appears to be targetted at deeply embedded, and solely at interleaving klog and console messages (not separate channels like logger)
Alan Cox said (explaining why a user-space solution wasn't sufficient):
On a lot of embedded systems you don't have all the stuff Fedora carts
around. No modules, initrds, magic front end processes, graphical startup
daemons etc, all of which work to produce that feature IFF you have pty
support in your kernel, and for the current code also glibc.
** How to use /dev/ttyprintk:
*** use 'setconsole /dev/ttyprintk < /dev/console' (see man setconsole(8))
*** write your own program to redirect this with a tty ioctl (see man tty_ioctl(4), section TIOCCONS)
Here is some sample code which should cause console messages to go to the printk log buffer:

/*Send console output through ttyprintk.*/
if ((fd = open("/dev/ttyprintk", O_WRONLY)) > 0) {
ioctl(fd, TIOCCONS, NULL);
close(fd);
}

==== [9] no need to switch to something new ====
* [9] Google doesn't see a need to invest in switching (Brian Swetland)
<pre>
Having a bunch of people suggest how we can just rewrite our userspace
to get something similar but not really the same as the functionality
we already have registers as "big waste of our time."

Replacing a tiny, self-contained, and reliable driver that's worked
for us for five-ish years with a pile of userspace surgery is
uninteresting to me.
</pre>

==== [10] Kay Siever's wishlist ====
* [10] Kay Siever's wishlist - kmsg with structured data (Kay Sievers - who else?)
** supports structured data, that can be used with current tools
** each record has timestamp, log facility, log level, string (no pid)
** timestamp converted on output (not saved as text in log)
** record dictionary (key=value pairs)
** single channel
** systemd has ASCII-like stream format for structured data
** on top of existing logbuf code

==== [11] avoid malicious log overruns ====
* [11] avoid log spam (Brian Swetland)
** logger could use separate channel per pid
** systemd journal maintains separate journal per uid (Kay)
** rate-limiting per uid or gid, is one way to handle this
*** this adds complexity, but consumes less space than having per-process logs

==== [12] per-process log security ====
* [12] allow for eventual per-process log security (Brian Swetland)
** logger could use multiple channels
** systemd journal maintains separate journal per uid (Kay)

==== [13] code cleanups for current driver ====
* [13] Specific code fixes in current driver (Andrew Morton, see https://lkml.org/lkml/2011/12/28/165)
** [13.1] ** MAINLINED in 3.4 - logger_offset macro depends on local 'log' variable
** [13.2] ** MAINLINED in 3.4 - should document endian-ness of numeric values in buffer
** [13.3] ** MAINLINED in 3.4 - do get_entry_len more neatly (possibly using packed_struct.h)
** [13.4] ** FIXED in 3.4 - use get_unaligned() instead of current get_entry_len() code??
** [13.5] ** MAINLINED in 3.4 - change order of prepare_to_wait and mutex_lock lines in logger_read()
** [13.6] ** MAINLINED in 3.4 - make clock_interval function more obvious
** [13.7] don't make clock_interval explicitly inline (gcc should figure it out)
** [13.8] ** MAINLINED in 3.4 - in do_write_log_from_user, update log->w_off ??
** [13.9] resolve pid, tgid confusion
** [13.10] consider access control for logs, especially in container context
** [13.11] ** MAINLINED in 3.4 - does reader->list need to be locked, in logger_release?
** [13.12] get rid of ioctl?
** [13.13] get rid of hardcoded minor names in get_log_from_minor()

== Project task list ==
* Get needed hardware
* Make sure contractors have all required source code:
** AOSP, Android kernels, and logger code
* Identify and review code before submission
** identify possible mainline objections to code, and plan how to respond
** compare with alternatives
*** compare and contrast logger code with kernel log buffer (e.g. dmesg vs. logcat)
**** performance, features, size,
*** compare and contrast logger code with syslog (syslogd, /var/log)
* Submit code to LKML
* Respond to feedback received
* Add logger code to busybox?
** Should this be done first?
** log
** logwrapper
** logsync
** What about logd_write.c code
*** included in bionic - should be included in busybox directly, because it's missing in glibc?
* what about udev?
** should mainline Linux automatically create logger devices nodes?
** they are created by 'init' in Android systems

== Volunteers ==
* Sisir Koppaka

== History ==
The proposals that led to this project are at:
* First proposal: [[Mainline Android kernel functionality]]
* Second proposal (more focused on just the logger): [[Mainline Android logger]]

[[Category:Android]]

Mainline Android logger project

2012-03-26T19:38:04Z

Frowand: /* [8] ttyprintk driver */

This page is for managing information related to the "Mainline Android Logger" project
of the CE Workgroup. This is part of the [[Android Mainlining Project]].

== Android logger issues ==
This section describes some attributes of the Android logger code, which are
relevant for mainlining the code into Linux. Let's use a modified SWOT (Strengths,
Weaknesses, Opportunities, Threats) analysis for strategic planning to mainline
this code.

To find the logger's strengths and weaknesses, lets research and provide information
and hard numbers for how it compares with existing logging alternatives.

=== Alternatives ===
What are the alternatives to the Android logger?
* logbuf (the kernel log buffer)
** apparently, systemd uses this
* syslog
* "the journal" - a new logging system for systemd (by Lennart Poettering)
** see [https://docs.google.com/document/pub?id=1IC9yOXj7j6cdLLxWEBAGRL6wl97tFxgjLUEHIX3MSTs&pli=1 systemd journal] for a good discussion of problems with syslog
* Neil Brown's log-pipe idea
** I thought this one was interesting. See: [http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/02484.html Neil Brown's message about this on LKML]
* Arnd Bergmann's tmpfs idea
** See [http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/02737.html this message]

What are the pros and cons of each system (see feature matrix below)

=== Existence ===
Does the system or proposed alternative currently exist?

How much work would it be to create it?

How much work would it be to test it to confirm that it had the same semantics as current Android logger?

=== Performance ===
How much overhead does each logging system have?

How long does it take to write 1 million messages, for each of the above systems?

How many context switches are required to log a single message?

How long is each message, on average?

How many data copies are performed for each message?

What is the average time to write each message, from the caller's perspective?

=== Size ===
What are the space requirements for each logging system?

what is the code footprint in the kernel?

What is the data footprint in the kernel?

What is the code footprint in user-space?

What is the data footprint in user-space?

Are any other modules are required solely to support logging?

What is the size required in persistent storage?

Can the size be limited (at compile-time?, at boot-time?, at run-time?)

Can the size be adjusted (at boot-time?, at run-time?)

Given default sizes, and expected logging rates, how much time does each system record?

=== Maintainability ===
How much does each system need to be maintained?

How many changes have been made to the each system in the last 3 years?

Are any significant changes expected in the future?

=== Configurability ===
What things can be configured at compile-time and run-time for each system?

=== Features ===
What features does each of the log systems have?

{| border="1" cellspacing="0" cellpadding="5"
|-bgcolor="#80c0d0"
!Attribute!!logger!!logbuf!!syslog!!Notes
|-
|multiple channels||yes||no||no?||allows for separation of data to prevent overrun
|-
|can limit space used||yes||yes||?||
|-
|cost to write 1M messages||?||?||?||need to benchmark
|-
|average cost to write a message||?||?||?||need to measure
|-
|average message size||?||?||?||need to measure
|-
|RAM required for complete logger system||?||?||?||need to measure (should include code space)
|-
|amount of flash or disk required for complete logger system||?||?||?||need to measure (should include code space)
|-
|user daemon required?||no||no||yes||syslog requires syslogd
|-
|networking required||no||no||no*||syslog requires network for some remote features
|-
|number of context switches per message||?||?||?||need to measure
|-
|logs both kernel and user messages?||no||no||yes?||klogd puts logbuf messages into syslog?
|-
|ability to store messages persistently on target||no||no*||yes||klogd puts logbuf messages into syslog?
|-
|ability to store messages persistently on host||yes*||no||yes
|
* adb logcat is builtin command for android
* you can use 'remote shell:dmesg >log.txt' on most embedded systems, but it's not really a design principle of logbuf
* syslog is built with remote message access integrated into the system
|-
|integrated into existing debug tools||yes||no?||no?||I don't know of anything but target-side tools (dmesg, cat /var/log) that "know" about logbuf and syslog
|-
|ability to filter messages by tag||yes||no||?||does syslog require tagging, is grep used for syslog tagging?
|-
|ease of use||high||low ||medium
|
* Android has facilities for logging available throughout the system (CLI, C/C++, Java), as well as good tool integration for readout and filtering
* klogd has 'echo >/dev/kmsg', but nothing else integrated into user-space stack
* syslog has logger, and libc calls (openlog, syslog, closelog)
|-
|tool support
|toolbox, adb
|busybox, standalone dmesg, klogd
|busybox, standalone logger, syslogd
|
|-
|API stability
|high*
|high
|high
|One change, to add 'system' channel in Android, in last 3 years. System channel separates system log messages from application log messages to prevent buffer exhaustion in case of a chatty application.
|}

=== Extension questions ===
Here are some questions about how the systems could be integrated:

* What features ''could'' each log system have, if extended?
* Would extension to an existing system interfere with it's current primary purpose?
* For each change contemplated, can it be implemented to minimize the impact to existing code?

=== Barriers to entry as is (Weaknesses) ===
Does logger duplicate functionality that exists elsewhere?
Does it make sense to extend an existing system, rather than implement a new system?

What are barriers to entry:
* use of ioctl?
* hardcoded number of log channels
* other style issues?
* longterm maintainer?

=== Attractive features of logger as is (Strengths) ===
What are the differentiating features of logger, compared to alternatives?

* minimal context switches for logging
* use of ring buffer automatically limits log size
* log is in memory (no cost to store unused log messages)
* all messages are tagged
* all messages have priority
* all messages have timestamp
* user-space program to filter messages by tag
* channel selection by user-space policy

== Discussions ==
This section has notes about discussions with the community kernel developers and with Google engineers,
with regards to mainlining this code

=== Google engineer requests/questions ===
* Google doesn't want to change their class libraries or debug system
** These have already shipped to developers and are integrated into other tools (eclipse log viewer)
** the Android system and over 200,000 applications already use the existing classes
** (So, can changes be made "under the hood" without changing the existing user interface?)

* Google requests that any changes submitted to mainline also be placed in their kernel repository (or Gerrit review queue), so they can see them when they do merges and are not caught off guard.
** I'm not sure the detailed steps required to perform this

* Question: Why did Google write their own code, instead of using syslog?
** Was it simply expedience, lack of familiarity with syslog, or are there specific reasons they wrote a new system (missing features, etc.)?

=== Community feedback/input/questions ===
* Greg KH - [http://driverdev.linuxdriverproject.org/pipermail/devel/2011-May/016658.html "At worse case, all of the code could go away and the normal logging interface be used, after it would be fixed up to handle the special needs that warranted the creation of the android logger code in the first place."]

* Alessio - In my opinion syslog shouldn't be compared with neither Android's logger nor logbuf because:
# Buggy syslog implementation (or future changes) could shutdown the entire log infrastructure (logger and logbuf aren't supposed to change a lot in future)
# Logbuf and logger don't require writeable file system access which is mandatory for syslog. A no-writeable files-system (or a file-system which allow only few writes) is a common situation in embedded world.
# Logbuf and logger don't require maintenance work (no rotate, compress or purge old log files). A mandatory feature in consumer devices.
The advantages of logger over logbuf are:
# Logger's logs are shared among a unknown number of user space programs
# <del>logbuf are writable only by kernel itself</del>
# Logger's log are separated: An wild user space program couldn't fill up all logs.
# Write path in logger is optimized over all else

=== December 2011 LKML discussion ===
Here is the thread:
* [http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/index.html#02419 on lkml.indiana.edu]
* [https://lkml.org/lkml/2011/12/21/477 on lkml.org]

Notes on specific issues:
==== [1] seems redundant with logbug/syslog(2) ====
* [1] logbuf/syslog(2) code seems to do this now (Greg KH, Kay Sievers)
** see systemd usage, which appears to coalesce stuff into /dev/kmsg
*** adding warts to logbuf doesn't seem like a great idea, it's already got realtime issues that were never solved
*** but integration with user and kernel messages could be nice
*** integration also requires some oddities
**** do you convert the log message fields (pid and priority) to structured text, and parse them out again later
**** note that systemd added support for priorities and/or tags to logbuf (Kay Seivers) see
** the ioctl for logger looks a lot like syslog(2), any way to consolidate?
*** you'd have to add channels to syslog(2), if you wanted to have separate channels

==== [2] hardcoded names and number of logs in user-space and the kernel ====
* [2] hardcoded names and number of logs in user-space and the kernel (David Brown, Neil Brown, Andrew Morton)
** no argument there (Brian Swetland)

==== [3] logbuf filesystem idea ====
* [3] logbuf filesystem idea (Neil Brown)
<pre>
If you created a 'logbuf' filesystem that used libfs to provide a single
directory in which privileged processes could create files then you wouldn't
need the kernel to "know" the allowed logs: radio, events, main, system.
The size could be set by ftruncate() (by privileged used again) rather than
being hardcoded.

You would define 'read' and 'write' much like you currently do to create a list of
datagrams in a circular buffer and replace the ioctls by more standard
interfaces:

LOGGER_GET_LOG_BUG_SIZE would use 'stat' and the st_blocks field
LOGGER_GET_LOG_LEN would use 'stat' and the st_size field
LOGGER_GET_NEXT_ENTRY_LEN could use the FIONREAD ioctl
LOGGER_FLUSH_LOG could use ftruncate
</pre>

** this fixes (2) by allowing arbitrary logs created by user space
*** unfortunately, the log channels don't exist until after user space is up a while
*** maybe could hardcode a mechanism for a default system log at startup, with other to follow
** Greg KH also asks why we need a new interface for this rather than logbuf/syslog(2)

==== [4] features, requirements and wishlist ====
* [4] features, requirements and wishlist (Brian Swetland)
** avoid hardcoding the names and sizes of the logs
** adjust permissions so that some apps can only read back their own log messages (security by pid or by channel?)
** allow logs to survive reboot
** allow an app to create it's own log, up to a specified size limit, but in a way that wouldn't
consume too much memory systemwide
<pre>
The goals behind the logger driver have been:
- keep userland and kernel logging separate (so that spammy userland
logging doesn't make us lose critical kernel logs or the other way
round)
- make log writing very inexpensive -- avoid having to pass messages
between processes (more critical on ARM9 platforms where this implied
extra cache flushing), avoid having to make several syscalls to write
a log message (getting time of day, etc), and so on
- make log writing reliable -- don't trust userland to report its
timestamp, PID, or to correctly format the datagrams, etc
- allow a log watching process (logcat) to easily pull data from all
logs at once
- avoid committing a vast amount of memory to logging
- try to prevent clients from spamming each other out of log space
(only successful on a coarse granularity right now with the
main/system/radio/events logs)
- ensure logs are not lost at the moment an app crashes
</pre>

==== [6] separate log channels are not needed ====
* [6] separate log channels are not needed or desirable (Kay Sievers)
** for early boot and debug, you want interleaving

==== [7] write cost is not a problem ====
* [7] write cost is not a problem (Kay Sievers, David Lang)
** I have no numbers, but suspect there is no problem

==== [8] ttyprintk driver ====
* [8] userspace printk tty (ttyprintk) driver (Greg KH, Kay Sievers mentioned it)
** I never heard of it - need to do some research I guess
** see linux/drivers/char/ttyprintk.c
** Feature was added in August 2010 (kernel version 2.6.36?)
** Results: ttyprintk allows user-space to submit messages to the kernel log buffer
*** ttyprintk features:
*** convert CR to LF,
*** adds '[U]' tag in front of each message
*** splits long messages into fragments no longer than 508 bytes
** (How is this different from /dev/kmsg???)
*** purpose appears to be to automatically grab messages from programs stdout that would normally be written to the system console
*** see thread about "console logging detour via printk" here: http://lkml.indiana.edu/hypermail/linux/kernel/1005.0/00009.html
*** I'm not sure how this is installed. (maybe with console=ttyprintk on the command line?)

** See http://www.kerneltrap.org/mailarchive/linux-kernel/2010/8/25/4611115 for Alan Cox's justification for this, compared to systemd on Fedora 14, or Kay Seiver's 'exec </dev/console >/dev/kmsg 2>&1'
*** '''CAUTION: 'exec </dev/console >/dev/kmsg 2>&1' crashes the Xserver on my Fedora 14 system'''
*** answering the question - what's different about this from /dev/kmsg
*** also: http://www.kerneltrap.org/mailarchive/linux-kernel/2010/8/25/4611254
*** A user-space program can do this message transfer (see Kay's thing above), but /dev/kmsg can't be a console because it's missing some ioctls that are expected for a tty device
*** this appears to be targetted at deeply embedded, and solely at interleaving klog and console messages (not separate channels like logger)
Alan Cox said (explaining why a user-space solution wasn't sufficient):
On a lot of embedded systems you don't have all the stuff Fedora carts
around. No modules, initrds, magic front end processes, graphical startup
daemons etc, all of which work to produce that feature IFF you have pty
support in your kernel, and for the current code also glibc.
** How to use /dev/ttyprintk:
*** use 'setconsole /dev/ttyprintk < /dev/console' (see man setconsole(8))
*** write your own program to redirect this with a tty ioctl (see man tty_ioctl(4), section TIOCCONS)
Here is some sample code which should cause console messages to go to the printk log buffer:

/*Send console output through ttyprintk.*/
if ((fd = open("/dev/ttyprintk", O_WRONLY)) > 0) {
ioctl(fd, TIOCCONS, NULL);
close(fd);
}

==== [9] no need to switch to something new ====
* [9] Google doesn't see a need to invest in switching (Brian Swetland)
<pre>
Having a bunch of people suggest how we can just rewrite our userspace
to get something similar but not really the same as the functionality
we already have registers as "big waste of our time."

Replacing a tiny, self-contained, and reliable driver that's worked
for us for five-ish years with a pile of userspace surgery is
uninteresting to me.
</pre>

==== [10] Kay Siever's wishlist ====
* [10] Kay Siever's wishlist - kmsg with structured data (Kay Sievers - who else?)
** supports structured data, that can be used with current tools
** each record has timestamp, log facility, log level, string (no pid)
** timestamp converted on output (not saved as text in log)
** record dictionary (key=value pairs)
** single channel
** systemd has ASCII-like stream format for structured data
** on top of existing logbuf code

==== [11] avoid malicious log overruns ====
* [11] avoid log spam (Brian Swetland)
** logger could use separate channel per pid
** systemd journal maintains separate journal per uid (Kay)
** rate-limiting per uid or gid, is one way to handle this
*** this adds complexity, but consumes less space than having per-process logs

==== [12] per-process log security ====
* [12] allow for eventual per-process log security (Brian Swetland)
** logger could use multiple channels
** systemd journal maintains separate journal per uid (Kay)

==== [13] code cleanups for current driver ====
* [13] Specific code fixes in current driver (Andrew Morton, see https://lkml.org/lkml/2011/12/28/165)
** [13.1] ** MAINLINED in 3.4 - logger_offset macro depends on local 'log' variable
** [13.2] ** MAINLINED in 3.4 - should document endian-ness of numeric values in buffer
** [13.3] ** MAINLINED in 3.4 - do get_entry_len more neatly (possibly using packed_struct.h)
** [13.4] ** FIXED in 3.4 - use get_unaligned() instead of current get_entry_len() code??
** [13.5] ** MAINLINED in 3.4 - change order of prepare_to_wait and mutex_lock lines in logger_read()
** [13.6] ** MAINLINED in 3.4 - make clock_interval function more obvious
** [13.7] don't make clock_interval explicitly inline (gcc should figure it out)
** [13.8] ** MAINLINED in 3.4 - in do_write_log_from_user, update log->w_off ??
** [13.9] resolve pid, tgid confusion
** [13.10] consider access control for logs, especially in container context
** [13.11] ** MAINLINED in 3.4 - does reader->list need to be locked, in logger_release?
** [13.12] get rid of ioctl?
** [13.13] get rid of hardcoded minor names in get_log_from_minor()

== Project task list ==
* Get needed hardware
* Make sure contractors have all required source code:
** AOSP, Android kernels, and logger code
* Identify and review code before submission
** identify possible mainline objections to code, and plan how to respond
** compare with alternatives
*** compare and contrast logger code with kernel log buffer (e.g. dmesg vs. logcat)
**** performance, features, size,
*** compare and contrast logger code with syslog (syslogd, /var/log)
* Submit code to LKML
* Respond to feedback received
* Add logger code to busybox?
** Should this be done first?
** log
** logwrapper
** logsync
** What about logd_write.c code
*** included in bionic - should be included in busybox directly, because it's missing in glibc?
* what about udev?
** should mainline Linux automatically create logger devices nodes?
** they are created by 'init' in Android systems

== Volunteers ==
* Sisir Koppaka

== History ==
The proposals that led to this project are at:
* First proposal: [[Mainline Android kernel functionality]]
* Second proposal (more focused on just the logger): [[Mainline Android logger]]

[[Category:Android]]

File:Real Time (BoFs).pdf

2012-02-23T21:21:40Z

Frowand:

PgpKey

2012-02-08T20:12:50Z

Frowand:

{|
| nowrap style="vertical-align: top; font: bold xx-large sans-serif;" |
PGP key web of trust
|}

The Linux kernel developers have become more interested in creating a pgp key based web of trust, following the recent kernel.org systems compromise.

H. Peter Anvin wrote an informative email on the subject. [https://lwn.net/Articles/461236/ copy on lwn] [https://lkml.org/lkml/2011/9/30/421 copy on lkml.org]

= Cheat sheet for creating a key, and signing other keys with it. =

More detailed instructions can be found at:

http://cryptnet.net/fdp/crypto/keysigning_party/en/keysigning_party.html#prep

== Before the key signing event ==

Generate a key:

$ gpg --gen-key

Here is a sample key generation dialogue:

<pre>
Please select what kind of key you want:
(1) RSA and RSA (default)
(2) DSA and Elgamal
(3) DSA (sign only)
(4) RSA (sign only)
Your selection? 1
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 5y
Key expires at Sun Feb 5 20:25:38 2017 PST
Is this correct? (y/N) y

You need a user ID to identify your key; the software constructs the user ID
from the Real Name, Comment and Email Address in this form:
"Heinrich Heine (Der Dichter) <heinrichh@duesseldorf.de>"

Real name: John Doe
Email address: jdoe@example.com
Comment:
You selected this USER-ID:
"John Doe <jdoe@example.com>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
You need a Passphrase to protect your secret key.

Enter Passphrase:
Repeat passphrase:

# You may be prompted to create some randomness. One way to do so is to
# use another shell to type: ls -lR >/dev/null

gpg: key 59E066B1 marked as ultimately trusted
public and secret key created and signed.

gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 2 signed: 36 trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: depth: 1 valid: 36 signed: 10 trust: 36-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2013-10-05
pub 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
Key fingerprint = 33E6 B4F8 F7E8 4C1B 4214 EEB3 DDE4 4949 59E0 66B1
uid John Doe <jdoe@example.com>
sub 4096R/DE192E71 2012-02-08 [expires: 2017-02-06]
</pre>

The key generated above is: 59E066B1

If you do not remember your key, get it:

$ gpg --list-secret-keys

<pre>
sec 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
uid John Doe <jdoe@example.com>
ssb 4096R/DE192E71 2012-02-08
</pre>

Put your key in a shell variable for use in the following commands
(replace xxxxxxxx with your key):

$ export MY_KEY="xxxxxxxx"

Send your signed key upstream, so others can download and sign it:

$ gpg --keyserver pgp.mit.edu --send-key ${MY_KEY}

Print the fingerprint for your key. Write this down to share with anyone
you want to sign your key. Bring this to the key signing event. If you
write this on the back of your badge, others can take a picture of it or
copy it by hand. Or you may wish to print many copies of the fingerprint
to give to others.

$ gpg --fingerprint ${MY_KEY}

Here is a sample fingerprint:

<pre>
gpg --fingerprint 59E066B1
pub 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
Key fingerprint = 33E6 B4F8 F7E8 4C1B 4214 EEB3 DDE4 4949 59E0 66B1
uid John Doe <jdoe@example.com>
sub 4096R/DE192E71 2012-02-08 [expires: 2017-02-06]
</pre>

== At the key signing event ==

* Collect the key finger print for each key you want to sign.
* Verify with the key owner that the fingerprint is correct.
* Verify the identity of the key owner. For example, check a difficult to forge photo ID. Or you may choose to rely on an extensive history of personal contact.

== At your convenience, sign the keys ==

Create a space separated list of keys:

$ export KEY_LIST="the keys I want to sign"

For example, the keys for Frank Rowand and Tim Bird are:

<pre>
$ export KEY_LIST="0CB2D395 793815d2"
</pre>

Download the keys from the server:

$ gpg --keyserver pgp.mit.edu --recv-keys ${KEY_LIST}

Manually verify that the fingerprints from this command match the fingerprints
that you collected for the keys:

$ gpg --fingerprint ${KEY_LIST}

Sign the keys (you will be prompted for your pass phrase):

$ for k in ${KEY_LIST} ; do gpg --default-key ${MY_KEY} --sign-key ${k} ; done

Send the signed keys to the server:

$ gpg --keyserver pgp.mit.edu --send-key ${KEY_LIST}

[[Category:Tools]]
[[Category:Development Tools]]

Source Management Tools

2012-02-08T19:58:32Z

Frowand:

Here are some different source management tools commonly used with Linux:

== Overview ==
* David Wheeler has an excellent breakdown of various SCM tools at: http://www.dwheeler.com/essays/scm.html
* IBM has an good overview of available tools at: http://www-128.ibm.com/developerworks/linux/library/l-vercon/
* There is a comparison of several different tools at: http://better-scm.berlios.de/comparison/comparison.html

== Patch Management Tools ==
* diff - to create patches
** use 'man diff' on your local system for information
* [http://wikipedia.org/wiki/Patch_%28Unix%29 patch] - to apply patches
** use 'man patch' on your local system for information
* [[Quilt]] is good for managing a group of patches relative to a single source base.
* diffstat reads a patch file (or standard input) and displays a histogram of the insertions, deletions, and modifications per-file. It is useful for reviewing large, complex patch files. It reads from one or more input files or from standard input. If an input filename ends with .bz2, .Z or .gz, diffstat will read the uncompressed data via a pipe from the corresponding program.
** diffstat is included in most Linux distributions
** [http://invisible-island.net/diffstat/diffstat.html diffstat home page]
** [http://www.die.net/doc/linux/man/man1/diffstat.1.html diffstat man page]
* [[Tim's patch management tools]] - diffinfo and friends - a more verbose diffstat, with splitting, joining and comparing of patches
* See also [[Diff And Patch Tricks]]

== Version Control Systems ==
* [[Git]]
* [[Subversion]]
* [[BitKeeper]]

== Identity Verification, text validation ==

* [[PgpKey]]

[[Category:Development Tools]]

Tools

2012-02-08T19:58:22Z

Frowand:

* [[addr2line for kernel debugging]]
* [[ioctl| decode an ioctl]]
* [[Exception Analysis tools]]
** This includes things like oops emitters, exception monitors, coredump analysis, etc.
* [[PgpKey]]

PgpKey

2012-02-08T19:57:21Z

Frowand:

{|
| nowrap style="vertical-align: top; font: bold xx-large sans-serif;" |
PGP key web of trust
|}

The Linux kernel developers have become more interested in creating a pgp key based web of trust, following the recent kernel.org systems compromise.

H. Peter Anvin wrote an informative email on the subject. [https://lwn.net/Articles/461236/ copy on lwn] [https://lkml.org/lkml/2011/9/30/421 copy on lkml.org]

= Cheat sheet for creating a key, and signing other keys with it. =

More detailed instructions can be found at:

http://cryptnet.net/fdp/crypto/keysigning_party/en/keysigning_party.html#prep

== Before the key signing event ==

Generate a key:

$ gpg --gen-key

Here is a sample key generation dialogue:

<pre>
Please select what kind of key you want:
(1) RSA and RSA (default)
(2) DSA and Elgamal
(3) DSA (sign only)
(4) RSA (sign only)
Your selection? 1
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 5y
Key expires at Sun Feb 5 20:25:38 2017 PST
Is this correct? (y/N) y

You need a user ID to identify your key; the software constructs the user ID
from the Real Name, Comment and Email Address in this form:
"Heinrich Heine (Der Dichter) <heinrichh@duesseldorf.de>"

Real name: John Doe
Email address: jdoe@example.com
Comment:
You selected this USER-ID:
"John Doe <jdoe@example.com>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
You need a Passphrase to protect your secret key.

Enter Passphrase:
Repeat passphrase:

# You may be prompted to create some randomness. One way to do so is to
# use another shell to type: ls -lR >/dev/null

gpg: key 59E066B1 marked as ultimately trusted
public and secret key created and signed.

gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 2 signed: 36 trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: depth: 1 valid: 36 signed: 10 trust: 36-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2013-10-05
pub 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
Key fingerprint = 33E6 B4F8 F7E8 4C1B 4214 EEB3 DDE4 4949 59E0 66B1
uid John Doe <jdoe@example.com>
sub 4096R/DE192E71 2012-02-08 [expires: 2017-02-06]
</pre>

The key generated above is: 59E066B1

If you do not remember your key, get it:

$ gpg --list-secret-keys

<pre>
sec 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
uid John Doe <jdoe@example.com>
ssb 4096R/DE192E71 2012-02-08
</pre>

Put your key in a shell variable for use in the following commands
(replace xxxxxxxx with your key):

$ export MY_KEY="xxxxxxxx"

Send your signed key upstream, so others can download and sign it:

$ gpg --keyserver pgp.mit.edu --send-key ${MY_KEY}

Print the fingerprint for your key. Write this down to share with anyone
you want to sign your key. Bring this to the key signing event. If you
write this on the back of your badge, others can take a picture of it or
copy it by hand. Or you may wish to print many copies of the fingerprint
to give to others.

$ gpg --fingerprint ${MY_KEY}

Here is a sample fingerprint:

<pre>
gpg --fingerprint 59E066B1
pub 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
Key fingerprint = 33E6 B4F8 F7E8 4C1B 4214 EEB3 DDE4 4949 59E0 66B1
uid John Doe <jdoe@example.com>
sub 4096R/DE192E71 2012-02-08 [expires: 2017-02-06]
</pre>

== At the key signing event ==

* Collect the key finger print for each key you want to sign.
* Verify with the key owner that the fingerprint is correct.
* Verify the identity of the key owner. For example, check a difficult to forge photo ID. Or you may choose to rely on an extensive history of personal contact.

== At your convenience, sign the keys ==

Create a space separated list of keys:

$ export KEY_LIST="the keys I want to sign"

Download the keys from the server:

$ gpg --keyserver pgp.mit.edu --recv-keys ${KEY_LIST}

Manually verify that the fingerprints from this command match the fingerprints
that you collected for the keys:

$ gpg --fingerprint ${KEY_LIST}

Sign the keys (you will be prompted for your pass phrase):

$ for k in ${KEY_LIST} ; do gpg --default-key ${MY_KEY} --sign-key ${k} ; done

Send the signed keys to the server:

$ gpg --keyserver pgp.mit.edu --send-key ${KEY_LIST}

[[Category:Tools]]
[[Category:Development Tools]]

PgpKey

2012-02-08T19:52:14Z

Frowand: Creating a pgp key. Signing keys to create a web of trust.

{|
| nowrap style="vertical-align: top; font: bold xx-large sans-serif;" |
PGP key web of trust
|}

The Linux kernel developers have become more interested in creating a pgp key based web of trust, following the recent kernel.org systems compromise.

H. Peter Anvin wrote an informative email on the subject. [https://lwn.net/Articles/461236/ copy on lwn] [https://lkml.org/lkml/2011/9/30/421 copy on lkml.org]

= Cheat sheet for creating a key, and signing other keys with it. =

More detailed instructions can be found at:

http://cryptnet.net/fdp/crypto/keysigning_party/en/keysigning_party.html#prep

== Before the key signing event ==

Generate a key:

$ gpg --gen-key

Here is a sample key generation dialogue:

<pre>
Please select what kind of key you want:
(1) RSA and RSA (default)
(2) DSA and Elgamal
(3) DSA (sign only)
(4) RSA (sign only)
Your selection? 1
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
0 = key does not expire
<n> = key expires in n days
<n>w = key expires in n weeks
<n>m = key expires in n months
<n>y = key expires in n years
Key is valid for? (0) 5y
Key expires at Sun Feb 5 20:25:38 2017 PST
Is this correct? (y/N) y

You need a user ID to identify your key; the software constructs the user ID
from the Real Name, Comment and Email Address in this form:
"Heinrich Heine (Der Dichter) <heinrichh@duesseldorf.de>"

Real name: John Doe
Email address: jdoe@example.com
Comment:
You selected this USER-ID:
"John Doe <jdoe@example.com>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
You need a Passphrase to protect your secret key.

Enter Passphrase:
Repeat passphrase:

# You may be prompted to create some randomness. One way to do so is to
# use another shell to type: ls -lR >/dev/null

gpg: key 59E066B1 marked as ultimately trusted
public and secret key created and signed.

gpg: checking the trustdb
gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model
gpg: depth: 0 valid: 2 signed: 36 trust: 0-, 0q, 0n, 0m, 0f, 2u
gpg: depth: 1 valid: 36 signed: 10 trust: 36-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2013-10-05
pub 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
Key fingerprint = 33E6 B4F8 F7E8 4C1B 4214 EEB3 DDE4 4949 59E0 66B1
uid John Doe <jdoe@example.com>
sub 4096R/DE192E71 2012-02-08 [expires: 2017-02-06]
</pre>

The key generated above is: 59E066B1

If you do not remember your key, get it:

$ gpg --list-secret-keys

<pre>
sec 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
uid John Doe <jdoe@example.com>
ssb 4096R/DE192E71 2012-02-08
</pre>

Put your key in a shell variable for use in the following commands
(replace xxxxxxxx with your key):

$ export MY_KEY="xxxxxxxx"

Send your signed key upstream, so others can download and sign it:

$ gpg --keyserver pgp.mit.edu --send-key ${MY_KEY}

Print the fingerprint for your key. Write this down to share with anyone
you want to sign your key. Bring this to the key signing event. If you
write this on the back of your badge, others can take a picture of it or
copy it by hand. Or you may wish to print many copies of the fingerprint
to give to others.

$ gpg --fingerprint ${MY_KEY}

Here is a sample fingerprint:

<pre>
gpg --fingerprint 59E066B1
pub 4096R/59E066B1 2012-02-08 [expires: 2017-02-06]
Key fingerprint = 33E6 B4F8 F7E8 4C1B 4214 EEB3 DDE4 4949 59E0 66B1
uid John Doe <jdoe@example.com>
sub 4096R/DE192E71 2012-02-08 [expires: 2017-02-06]
</pre>

== At the key signing event ==

* Collect the key finger print for each key you want to sign.
* Verify with the key owner that the fingerprint is correct.
* Verify the identity of the key owner. For example, check a difficult to forge photo ID. Or you may choose to rely on an extensive history of personal contact.

== At your convenience, sign the keys ==

Create a space separated list of keys:

$ export KEY_LIST="the keys I want to sign"

Download the keys from the server:

$ gpg --keyserver pgp.mit.edu --recv-keys ${KEY_LIST}

Manually verify that the fingerprints from this command match the fingerprints
that you collected for the keys:

$ gpg --fingerprint ${KEY_LIST}

Sign the keys (you will be prompted for your pass phrase):

$ for k in ${KEY_LIST} ; do gpg --default-key ${MY_KEY} --sign-key ${k} ; done

Send the signed keys to the server:

$ gpg --keyserver pgp.mit.edu --send-key ${KEY_LIST}

[[Category:Tools]]

Help:Starting a new page

2012-02-08T19:51:49Z

Frowand:

{{PD Help Page}}
There are several ways to start a new page. These can vary based on the type of page started, as well as the wiki and namespace.

== Using Wikilinks ==
MediaWiki makes it very easy to link wiki pages using a standard syntax (see [[Help:Links|Links]]). If you (or anyone else) create a link to an article that doesn't exist yet, the link will be coloured red, <span style="color: #ba0000">like this</span>.

Clicking a red link will take you to the edit page for the new article. Simply type your text, click save and the new page will be created.

Once the page has been created, the link will change from <span style="color: #ba0000">red</span> to <span style="color: #002bb8;">blue</span> (<span style="color: #5a3696;">purple</span> for pages you've visited) indicating that the article now exists.

Usually this is the best way to create a new page, because it means that right from the start, the page will be linked from at least one other place on the wiki (and typically you will want to mesh it into other related pages later). If you are creating a new page without creating any link to it, you may need to ask yourself: Does this page really fit in with the topics already covered in the wiki? Also, how are you expecting visitors to find this page? Normally there is no reason to create a page without first creating a red link to it.

== From the search page ==
If you search for a page that doesn't exist (using the search box and “{{int:go}}” button on the left of the page) then you will be provided with a link to create the new page.

== Using the URL ==
You can use the wiki's URL for creating a new page. The URL to an article of the wiki is usually something like this:
*<code><nowiki>http://www.example.net/index.php/</nowiki>'''ARTICLE'''</code>    or
*<code><nowiki>http://www.example.net/wiki/</nowiki>'''ARTICLE'''</code>

If you replace <code>'''ARTICLE'''</code> with the name of the page you wish to create, you will be taken to a blank page which indicates that no article of that name exists yet. Clicking the "{{int:edit}}" [[Help:Navigation#Page Tabs|page tab]] at the top of the page will take you to the edit page for that article, where you can create the new page by typing your text, and clicking submit.

== Create redirects to your new page ==
Don't forget to set up redirects when you create a page. If you think another person may search for the page you've created by using a different name or spelling, please create the proper redirect(s). See [[Help:Redirects]]

== Add your new page to a category ==

See [[Help:Categories]]

== Protecting your new page ==
Normally a new wiki page can be edited by other people (that is one of the main ideas of a wiki!) However, a sysop could '[[Help:Protected pages|protect]]' the page, if desired, to prevent normal users from editing it.

{{Languages}}

[[Category:Help|Starting a new page]]

ELC 2012 Technical Showcase

2012-02-08T03:01:02Z

Frowand: /* Criteria */

[[image:elc2006-showcase1.jpg|Embedded Linux Conference 2006 Technical Showcase]]

= Embedded Linux Conference 2012 Technical Showcase =

We are happy to be planning a technical showcase again this year at Embedded Linux Conference. This Wiki page will guide you in giving your demonstration. For conference details, please follow this link to the conference website:
* http://events.linuxfoundation.org/events/embedded-linux-conference/

[[image:elc2006-showcase2.jpg|Embedded Linux Conference 2006 Technical Showcase]]
[[image:elc2006-showcase3.jpg|Embedded Linux Conference 2006 Technical Showcase]]

== Details ==
The demo session will be on Thursday, February 16th, between 6:30 and 8:00 pm in the Grand Salon.

The demo room will be available starting at '' '''6:00 pm''' '' for demo setup.

== Objective ==
"Seeing is believing!" Unlike in Desktop or Server applications of Linux, in embedded systems Linux technology is usually unseen. Although it is a challenge, we want to expose Linux software and techniques so that other developers who are interested in this technology can learn, and become potential contributors themselves. We hope that through opening up technical details and projects (in the way of Open Source development), these demonstrations will provide insights that are helpful to developers.

== Criteria ==
* No ''purely'' commercial demonstrations.
* The Embedded Linux Conference should not be used for a pure sales pitch.
* You can show off a product, if there are features or aspects of the product you are displaying that are open source.
* Demonstrations should be of software that is available under an open source license.

== Coordinator ==

Tim Bird - Sony Network Entertainment
* e-Mail : tim (dot) bird (a) am (dot) sony (dot) com
* Please replace (a) to "@" and (dot) to "."

= What will be prepared by the Linux Foundation =

The Linux Foundation will provide the following '''FREE OF CHARGE''' :
* A Demonstration desk, which is half of a table <br />If you need special arrangements, please contact the coordinator.
[[image:elc2006-showcase-desksample.jpg|Desk sample from ELC 2006]]
* Power supply: US standard, possibly shared with other demo on table - assume no more than 2 plugs available, which you may split further if needed.
* Assume the power is less than 750W. If your demonstration will exceed that, please consult the coordinator.
* A large-format printed poster, based on the file you submit.
* Please note that a dedicated (wired) Internet connection will '''NOT''' be prepared. However, wireless Internet may be available via the hotel wireless network. We cannot, however, guarantee Internet access.
* Logistics Support
* Details will be given to the demonstrators

== Dimension of the desk ==
* Please refer to the attached photo.

== Poster ==
All demonstrators are requested to prepare a poster to explain the technical outline of the demonstration. You can download the template from this page. CELF will print them out on large size paper. The document should be sent to the coordinator by February 8th.
* [[Media:ELC-2012_PosterForm.odp|ELC-2012_PosterForm.odp]]
* [[Media:ELC-2012_PosterForm.ppt|ELC-2012_PosterForm.ppt]]

'''Caution''': Do not change the paper size. It is intentionally set to a big size.

== Some tips ==
The demo consists of a poster (printed by the Linux Foundation), with
a few sentences talking about a tool, technology or distribution
and a table top where you can place anything from:

# nothing at all, just have a person sitting there to talk to people about what's on the poster, or ...
# something on a laptop - like a program running or a even a static chart showing some result
# something running on a board or a device
# something on an actual CE product

You can also put some flyers there for people to grab, if you'd like.

If you can put charts and graphs on the poster, that's nice
but it is NOT required. Neither the poster nor the
hardware (if any) needs to be elaborate or require lots of setup.
One year I showed up with a camcorder and just talked to
people about it's bootup time (which I had worked on).

If you are a presenter, the demo session is a good chance to talk to people
one-on-one about your session topic. This gives you more time for interactive
Q&A, and a chance to show something hands-on, if that applies to your subject.

= How to apply =
# Send an e-mail to the coordinator with the following information:
## The contact person, the company name or the project name, the outline of the demonstration.
## The coordinator will acknowledge your application by e-mail.
## Please send your application for the demo session no later than '''February 6th'''.
# Prepare the poster and send the data to the demonstration coordinator by '''February 8th'''. It will be printed out by the conference organizers on big size paper.
## Prepare the demonstration equipment
## You can bring the equipment yourself, or ship it.
## If you do not have a consignee which will be convenient for you, send them to the following address: ''Address not available yet'' (ask Tim for the Address if you are shipping something separately.)

= FAQ =
* '''Q''': Is this opportunity limited to CE Workgroup or Linux Foundation members?'''
* '''A''': No. You do not have to be a forum member to have a demo at the conference. However, each demo should be associated with a paid conference attendee.
* '''Q''': Is the demonstrator required to make a presentation at the conference?'''
* '''A''': No, this is not required. However, we believe there will be many people who will to be interested in details of the technology, so we hope that you can have a session. Please note that the due date for a session proposal is earlier than the due date for demo sign-up.
* '''Q''': Should I assign some dedicated staff to carry on the demonstration?'''
* '''A''': No, this is not necessary. There will be a dedicated time slot for the demos that will be separate from the other technical sessions. So there should be no conflict between the demo session and the other technical sessions.
* '''Q''': Is there any fee to demo something in this session?'''
* '''A''': No, the demo session is completely free.
* '''Q''': Can an non-attendee help present the demo?
* '''A''': If you have someone coming who will ONLY run or assist with your demo, and not attend any sessions, then that person may be admitted for free, for just the demo session (and setup and take down). However, each demo should be associated with at least one registered attendee.

[[Category:ELC]]
[[Category:2012]]
[[Category:Events]]

Japan Technical Jamboree 39

2011-12-08T02:19:17Z

Frowand: /* Agenda */

{| cellpadding="0" cellspacing="0" border="0"
|-
|[[Image:HeadTitle.gif]]
|-
| style="text-align:right" |<span style="font-size:large">Date: December 9th/ 日付: 12月9日（金）</span>
At Nakano Sunplaza / 於、中野サンプラザ
|-
|[[Image:J_Jam_SessionProp.gif]]
|-
|style="text-align:right" |[[Japan TJ Session Proposal|<span style="color:red">Session proposal how-to. / 提案の方法</span>]]
|}

= Introduction / はじめに =
* The Japan Technical Jamboree is a forum-wide technical meeting of the CE Linux Forum. This meeting will be located conveniently in Japan and use Japanese as the native language of the event.
* A general guidance page is available. / 初めての方はこちらもお読みください。
** [http://tree.celinuxforum.org/CelfPubWiki/JapanTechnicalJamboreeGuidance JapanTechnicalJamboreeGuidance] (Japanese/English)
== Special remarks for non Japanese speakers ==
* This page is Japanese/English bilingual. Please allow some contents on this page are not translated into English because of this event is Japan regional one, though we try to place English translation.
* If you would like to perform your presentation in English, we also welcome you to join! We hope you to speak slowly without any complicated expressions. Most Japanese developers are capable to understand plain English.
== Previous Jamboree ==
* Please look into the wiki page. / 下記のWikiページをご覧ください。
** [[Japan Technical Jamboree 38]]

= Date and venue... / 日付・場所... =
{|
|+
|-
| style="vertical-align:top" |
[[Image:Nakano Sunplaza.jpg]]
| style="vertical-align:top; background-color:#F0F0F0" width=90% |
* Date '''December 9th, 2011'''
** '''Starting at 10 am'''
* At '''''Nakano Sunplaza''''' / 会場 '''''中野サンプラザ'''''
** Nakano Sunplaza is located just close to '''Nakano''' station (JR/Tokyo Metoro ).
** http://www.sunplaza.jp/ (Japanese)
* Admission: '''''Free of charge''''' / 参加費用: '''''無料'''''
* Not limited for CELF members. / CELF会員以外も参加・セッション持ち込み共に可能
* Coordinators / 世話役 (Your inquiries in English welcome)
** Hisao Munakata / 宗像尚郎 (hisao_dot_munakata_dot_vt(a)renesas_dot_com)
** Satoru Ueda / 上田理 (Satoru_dot_Ueda(a)jp_dot_sony_dot_com)
|}
== Registration / 参加登録 ==
* No registration required / 参加登録は要りません。

= Main Topics =
* It is just after the ELC Europe!
: Embedded Lunux Conference まであと二ヶ月のタイミングです！

= Agenda / 進行 =
== Agenda ==

{|
|+
! style="text-align:left; background-color:#B0FFB0; width:50" | Time
! style="text-align:left; background-color:#B0FFB0; width:70%" | Title and presenter
! style="text-align:left; background-color:#B0FFB0" | Notes
Presentation Materials
|-
| style="vertical-align:top; background-color:#F0F0F0" | 10:00..
| style="vertical-align:top; background-color:#F0F0F0" |
* Opening / 連絡事項
* '''CE Linux Forum to go with The Linux Foundation (S. Ueda, CELF Marketing Gp. Chair)'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 10:30am..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Connected from USA'''
* '''Tim Bird'''
** Latest Community topics update
** Latest CE WG project updates
| style="vertical-align:top; background-color:#F0F0F0" |
* (In English / 英語のセッションです)
|-
| style="vertical-align:top; background-color:#F0F0F0" | 12:00..
| style="vertical-align:top; background-color:#F0F0F0" |
Lunch
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 1:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Repeat! ELC-E 2011: Contributing to the Community? Does your manager support you?'''
* '''S. Ueda'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 2:00pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Repeat! ELC-E 2011: How Linux-RT Works'''
* '''Frank Rowand'''
* '''Connected from USA'''
| style="vertical-align:top; background-color:#F0F0F0" |
* [[File:How_linux_preempt_rt_works_111207_1100.pdf‎]]
* (In English / 英語のセッションです)
|-
| style="vertical-align:top; background-color:#F0F0F0" | 2:45pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''A topics about Android Compatibility Definition'''
* '''Shinsuke Kato (Panasonic)'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 3:30pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Status of LTSI project'''
* '''Hisao Munakata'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 4:30pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Evaluation of IEEE802.3az on Linux Ethernet Driver'''
* '''Hiroo MATSUMOTO, FUJITSU COMPUTER TECHNOLOGIES LIMITED'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 4:50pm..
| style="vertical-align:top; background-color:#F0F0F0" |
'''Evaluation of IEEE1588 on Linux Ethernet Driver'''
* '''Akio MORI, FUJITSU COMPUTER TECHNOLOGIES LIMITED'''
| style="vertical-align:top; background-color:#F0F0F0" |
|-
| style="vertical-align:top; background-color:#F0F0F0" | 5:10pm..
| style="vertical-align:top; background-color:#F0F0F0" |
* '''''Calling for your session proposals'''''
| style="vertical-align:top; background-color:#F0F0F0" |
* [[Japan TJ Session Proposal|<span style="color:red">Session proposal how-to. / 提案の方法</span>]]
| style="vertical-align:top; background-color:#F0F0F0" |
| style="vertical-align:top; background-color:#F0F0F0" |
|}

* Please be noted above time table is just a guideline and may be shifted. / 上記の時間割は目安です。かなり前後する可能性がありますので、あらかじめご承知おきください。

== Special Remarks ==
* Please place some detail descriptions about each presentation topics.
: こちらに各プレゼンテーションの詳細などを記載してください。
* Tweets in Japanese.http://togetter.com/li/138027

= Ask for your help / お願い =
== Presentation Materials ==
* We wish you to prepare the materials in English. / 出来るだけプレゼンテーション資料は英語で表記してください。絶対ではありませんが、日本語が理解できない方に対しての配慮が出来ればと思います。
* Please leave your material in this wiki site after the event. / ジャンボリー終了後、プレゼンテーション資料はこのWikiに残してください。
== English Translation Volunteer ==
* If you can help the translation volunteer from Japanese to English, we would be very much appreciated! / 日本語を英訳していただくボランティアを大歓迎します！

[[Category:Japan Technical Jamboree]]
[[Category:Events]]

File:How linux preempt rt works 111207 1100.pdf

2011-12-08T02:16:14Z

Frowand:

File:Elce11 rowand.pdf

2011-10-29T08:03:30Z

Frowand: uploaded a new version of "File:Elce11 rowand.pdf": The actual version that was presented.

File:Elce11 rowand.pdf

2011-10-27T21:05:49Z

Frowand: uploaded a new version of "File:Elce11 rowand.pdf"

Real Time

2011-10-27T11:36:19Z

Frowand: /* Documents */

This page has information about Real-time usage of Linux. Also this page has information about timing systems for Linux. This is of interest to CE Linux Forum members, because many consumer electronics products have realtime requirements (e.g. in the areas of multi-media presentation, or communications)

== Real Time Wiki ==
* Please note that the primary source of information for Real Time Linux information is the new [http://rt.wiki.kernel.org/ RTWiki].

== Technology/Project pages ==
* [[Realtime Preemption]] - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
* [[Kernel Timer Systems]] - Various new proposals for changing the kernel timing system
* [[Soft IRQ Threads]] - Technology to put SoftIRQs in threads so they can be preempted.
** '' '''NOTE:''' Soft IRQ threads are now (Oct 2007) incorporated into the [[Realtime Preemption]] patch ''
* [[High Resolution Timers]] - A system to support timers with sub-jiffy resolution
* [[Variable Scheduling Timeouts]] - A system to support variable timeouts for periodic system activities (also known as Tickless)

== Documents ==
* [http://www.amazon.com/Building-Embedded-Linux-Systems-Yaghmour/dp/0596529686 Building Embedded Linux Systems, 2nd edition] discusses the realtime preemption patch.
* [http://tree.celinuxforum.org/CelfPubWiki/RTSpecDraft_5fR2 CELF Realtime Specification] (from 2004, so it's pretty old)
*Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - [[Media:Real-Time-Preemption-Patchset.pdf]]
* [[Realtime Testing Best Practices]] - a document to show recent testing results, and give hints for how different tests are conducted and what pitfalls to avoid.
* [http://free-electrons.com/articles/realtime/ Real time in embedded Linux systems]
* [http://www.celinux.org/elc08_presentations/Using_Real-Time_Linux.KlaasVanGend.ELC2008.pdf Using Real-Time Linux] - Presentation by Klaas van Gends at the ELC 2008. The [http://free-electrons.com/pub/video/2008/elc/elc2008-klaas-van-gend-using-real-time-linux.ogg video] is available
* Frank Rowand's series of talks
** ''Adventures in real-time performance tuning''
*** Part 1, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_1-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part1.ogv video] ELCE 2008 version
*** Part 2, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_2-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part2.ogv video] ELCE 2008 version
** Musings On Analysis of Measurements of a Real-Time Workload [http://tree.celinuxforum.org/CelfPubWiki/ELC2009Presentations?action=AttachFile&do=get&target=musings_on_analysis_of_measurements_of_a_real-time_workload.pdf slides] ELC 2009 version and [http://free-electrons.com/pub/video/2009/elce/elce2009-rowand-measurement-diagnostic-tools.ogv video]
** Real-Time Linux Failure [[Media:Real_time_linux_failure.pdf|slides]] ELC 2010 version and [http://free-electrons.com/pub/video/2011/elc/elc-2011-rowand-real-time-issues-i-cache-locks.webm full HD video] and [http://free-electrons.com/pub/video/2011/elc/elc-2011-rowand-real-time-issues-i-cache-locks-x450p.webm 450x800 video]
** How Linux PREEMPT_RT Works [[Media:elce11_rowand.pdf|slides]] ELCE 2011 version
* ''Real-time vs real-fast, how to choose'', conference given by Paul E. McKenney at the Ottawa Linux Symposium 2008. [http://ols.fedoraproject.org/OLS/Reprints-2008/mckenney-reprint.pdf Paper] and [http://free-electrons.com/pub/video/2008/ols/ols2008-paul-mckenney-real-time-vs-real-fast.ogg video]

* Paper: "[http://www.reliableembeddedsystems.com/pdfs/2010_03_04_rt_linux.pdf Embedded GNU/Linux and Real-Time an executive summary]", 2010 by Robert Berger
** This papers, prepared for the Embedded World Conference 2010, compares different real-time approaches (including PREEMPT_RT and dual-kernel approaches).
** The paper has an extensive list of references.
* Tutorial [[RT-Preempt Tutorial]]
* [https://www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html OSADL Realtime Page] with realtime latency [https://www.osadl.org/Continuous-latency-monitoring.qa-farm-monitoring.0.html testing] farm.

== Further Open Source Projects ==
* [http://www.xenomai.org Xenomai] - Real-time development framework, closely cooperating with the Linux kernel. Among other features, it provides a migration path from various RTOSes like VxWorks, PSOS+, etc. to Linux based on so-called skins.

[[Category:Real Time]]

Real Time

2011-10-27T11:27:06Z

Frowand: /* Documents */

This page has information about Real-time usage of Linux. Also this page has information about timing systems for Linux. This is of interest to CE Linux Forum members, because many consumer electronics products have realtime requirements (e.g. in the areas of multi-media presentation, or communications)

== Real Time Wiki ==
* Please note that the primary source of information for Real Time Linux information is the new [http://rt.wiki.kernel.org/ RTWiki].

== Technology/Project pages ==
* [[Realtime Preemption]] - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
* [[Kernel Timer Systems]] - Various new proposals for changing the kernel timing system
* [[Soft IRQ Threads]] - Technology to put SoftIRQs in threads so they can be preempted.
** '' '''NOTE:''' Soft IRQ threads are now (Oct 2007) incorporated into the [[Realtime Preemption]] patch ''
* [[High Resolution Timers]] - A system to support timers with sub-jiffy resolution
* [[Variable Scheduling Timeouts]] - A system to support variable timeouts for periodic system activities (also known as Tickless)

== Documents ==
* [http://www.amazon.com/Building-Embedded-Linux-Systems-Yaghmour/dp/0596529686 Building Embedded Linux Systems, 2nd edition] discusses the realtime preemption patch.
* [http://tree.celinuxforum.org/CelfPubWiki/RTSpecDraft_5fR2 CELF Realtime Specification] (from 2004, so it's pretty old)
*Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - [[Media:Real-Time-Preemption-Patchset.pdf]]
* [[Realtime Testing Best Practices]] - a document to show recent testing results, and give hints for how different tests are conducted and what pitfalls to avoid.
* [http://free-electrons.com/articles/realtime/ Real time in embedded Linux systems]
* [http://www.celinux.org/elc08_presentations/Using_Real-Time_Linux.KlaasVanGend.ELC2008.pdf Using Real-Time Linux] - Presentation by Klaas van Gends at the ELC 2008. The [http://free-electrons.com/pub/video/2008/elc/elc2008-klaas-van-gend-using-real-time-linux.ogg video] is available
* Frank Rowand's series of talks
** ''Adventures in real-time performance tuning''
*** Part 1, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_1-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part1.ogv video] ELCE 2008 version
*** Part 2, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_2-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part2.ogv video] ELCE 2008 version
** Musings On Analysis of Measurements of a Real-Time Workload [http://tree.celinuxforum.org/CelfPubWiki/ELC2009Presentations?action=AttachFile&do=get&target=musings_on_analysis_of_measurements_of_a_real-time_workload.pdf slides] ELC 2009 version and [http://free-electrons.com/pub/video/2009/elce/elce2009-rowand-measurement-diagnostic-tools.ogv video]
** Real-Time Linux Failure [[Media:Real_time_linux_failure.pdf|slides]] ELC 2010 version
** How Linux PREEMPT_RT Works [[Media:elce11_rowand.pdf|slides]] ELCE 2011 version
* ''Real-time vs real-fast, how to choose'', conference given by Paul E. McKenney at the Ottawa Linux Symposium 2008. [http://ols.fedoraproject.org/OLS/Reprints-2008/mckenney-reprint.pdf Paper] and [http://free-electrons.com/pub/video/2008/ols/ols2008-paul-mckenney-real-time-vs-real-fast.ogg video]

* Paper: "[http://www.reliableembeddedsystems.com/pdfs/2010_03_04_rt_linux.pdf Embedded GNU/Linux and Real-Time an executive summary]", 2010 by Robert Berger
** This papers, prepared for the Embedded World Conference 2010, compares different real-time approaches (including PREEMPT_RT and dual-kernel approaches).
** The paper has an extensive list of references.
* Tutorial [[RT-Preempt Tutorial]]
* [https://www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html OSADL Realtime Page] with realtime latency [https://www.osadl.org/Continuous-latency-monitoring.qa-farm-monitoring.0.html testing] farm.

== Further Open Source Projects ==
* [http://www.xenomai.org Xenomai] - Real-time development framework, closely cooperating with the Linux kernel. Among other features, it provides a migration path from various RTOSes like VxWorks, PSOS+, etc. to Linux based on so-called skins.

[[Category:Real Time]]

ELC Europe 2010 Presentations

2010-10-28T15:32:17Z

Frowand: /* Table of Presentations */

Presenters, Demo-ers, Participants:
Thanks very much for your participation in CELF's [http://www.embeddedlinuxconference.com/elc_europe10/index.html Embedded Linux Conference Europe 2010].

This page is for collecting the presentations that were made at the conference. During and
after the conference we will collect materials from the presenters and place them here.
Please watch this page if you are interested in a particular presentation - and it if
doesn't show up, please send me an e-mail and we'll try to track it down.

== Videos ==

Videos from the conference were recorded by [http://free-electrons.com/ Free Electrons]
These will be made available as soon as they have time to transcode them for Internet
download. An announcement will be made, and a link placed here, when these are ready.

== Instructions ==
'''Presenters:''' Please post your technical conference presentations on this page.
(See Instructions below the tables)

== Table of Presentations ==

{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Keynotes'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|Ralf Baechle
|Embedded Linux - The State of the Nation
|
|-
|Ari Rauch
|The Dynamic Role of Open Linux Architectures in Today's Mobile Landscape
|
|}

<br />

{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Presentations'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|Andrew Murray
|The Right Approach to Minimal Boot Times
|
|-
|Andrey Fedotov
|Linux Application in Safety-Critical Environment: A Real-Life Example
|
|-
|Anna Dushistova
|Eclipse and Embedded Linux Developers: What It Can and What It Cannot Do For You
|
|-
|Armijn Hemel
|Introducing the Binary Analysis Tool
|
|-
|[mailto:arnout@mind.be Arnout Vandecappelle]
|[http://www.mind.be/?page=embedded-software-testing Practical Testing of Open Source Embedded Systems]
|[[Media:Embedded_software_testing.pdf|PDF]], [[Media:Embedded_software_testing.odp|Editable (odp)]]
|-
|Arun Raghavan
|PulseAudio In The Embedded World
|
|-
|Benjamin Gaignard
|Android and GStreamer
|[[Media:Android_and_Gstreamer.ppt|Android_and_GStreamer.ppt]]
|-
|Benjamin Zores
|State of Multimedia in 2010's Embedded Linux Devices
|[[Media:State_of_Multimedia_in_2010_Embedded_Linux_Devices.pdf|State_of_Multimedia.pdf]]
|-
|Carmelo Amoroso and Rosario Contarino
|Lightweight Prelinker for Kernel Modules
|
|-
|David Anders
|Board Bringup: Methods and Utilities
|
|-
|Frank Rowand
|Identifying Embedded Real-Time Latency Issues: I-Cache and Locks
|[[Media:Rt_latency_cache_and_locks.pdf|Rt_latency_cache_and_locks.pdf]]
|-
|Grant Likely
|ARM Flattened Device Tree Status Report
|
|-
|Gustavo F. Padovan
|The Linux Bluetooth Stack
|
|-
|Hans Verkuil
|Supporting SoC Video Subsystems in Video4linux
|[[Media:SoC_and_V4L2.odp|SoC_and_V4L2.odp]]
|-
|Harald Welte
|Running your own GSM+GPRS network using OpenBSC, OsmoSGSN and OpenGGSN
|[[Media:elce2010-welte-openbsc.pdf|OpenBSC.pdf]]
|-
|Iago Toral Quiroga
|Grilo: Integrating Multimedia Content in Applications
|
|-
|Jake Edge
|Understanding Threat Models for Embedded Devices
|
|-
|Jean-Paul Saman
|Porting VLC to TI DaVinci
|
|-
|[mailto:kees-jan.dijkzeul@sioux.eu Kees-Jan Dijkzeul]
|A Gentle Introduction to Autotools
|[[Media:101028-autotools-celf.odp|101028-autotools-celf.odp]] [[Media:autotools-demo-code.tgz|demo code]]
|-
|Kevin Hilman
|Runtime Power Management
|
|-
|Klaas Van Gend
|Deflating the Virtualization Hype in 3 Simple Steps
|
|-
|Koen Kooi
|The State of OpenEmbedded and Tooling to Make Life Easier
|
|-
|Leif Lindholm
|Software Considerations When Using High-Performance Memory Systems
|
|-
|Michael Opdenacker
|Flash Filesystem Benchmarks
|
|-
|Peter Korsgaard
|Do More With Less - On Driver-less Interfacing with Embedded Devices
||[[Media:Do_more_with_less.pdf|Do_more_with_less.pdf]]
|-
|Philippe Robin
|Facilitating Open Source Development and Collaboration
|
|-
|Ray Kinsella
|Xen in Embedded Systems
|[[Media:Xen_in_Embedded_Systems.pdf|Xen_in_Embedded_Systems.pdf]]
|-
|Robert Schuster
|OpenJDK for Embedded Linux Devices
|[[Media:Cross-compiling_OpenJDK.pdf|Cross-compiling_OpenJDK.pdf]]
|-
|Robert Schwebel and Sascha Hauer
|Barebox: Booting Linux Fast and Fancy
|
|-
|Ruud Derwig and/or Mischa Jonker
|Portability Is For People Who Cannot Write New Programs - Experience with GNU, LINUX, and other Open Source on ARC Processors
|
|-
|Stefan Kost
|Meego Multimedia
|
|-
|Tim Bird
|Android System Programming - Tips and Tricks
|[[Media:Android-tips-and-tricks-2010-10.pdf|Android-tips-and-tricks-2010-10.pdf]]
|-
|Wolfram Sang
|Developer's Diary: Supporting Maintainers
|
|-
|Wookey
|YAFFS Updates
|
|-
|Yann E. Morin
|Crosstool-NG, A Cross-Toolchain Generator
|
|-
|Yoshitake Kobayashi
|Linux Kernel Acceleration for Long-term Testing
|
|}

<br />

{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Short Sessions'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|John Ogness
|IPL+UBI: Flexible and Reliable with Linux as the Bootloader
|[[Media:ipl_and_ubi.pdf | ipl_and_ubi.pdf]]
|-
|Martin Michlmayr
|Adapting Debian Installer to NAS and Other Consumer Devices
|
|-
|Ravi Sankar Guntur
|A Simple Method to Detect Memory Leaks and Buffer Overruns
|[[Media:SafeMem-ELC-E-2010.pdf | SafeMem-ELC-E-2010.pdf]]
|
|-
|Vitaly Wool
|Porting Legacy Code to Linux Userspace Driver Framework
|
|-
|Will Newton
|Exploiting On-chip Memories in Embedded Linux Applications
|
|}

<br />

{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Birds-of-a-Feather Sessions (BOFS)'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|David Anders - Jayabharath Goluguri
|OMAP3/4 BoF
|
|-
|Frank Scholz
|Android and Its Impact On Home Entertainment and Home Automation
|
|-
|Grant Likely
|Small Business Owners BoF
|
|}

<br />

{| border="1" cellspacing="0" cellpadding="4"
|- bgcolor="#c0e0e0"
|+ '''Tutorial workshops'''
|- bgcolor="#c0e0e0"
| align="center" | '''Presenter(s)'''
| align="center" | '''Session Description'''
| align="center" | '''Presentation'''
|-
|Chris Simmonds
|The Embedded Linux Quick Start Guide
|[[Media:linux-quick-start.tar.gz|linux-quick-start.tar.gz]]
|-
|Chris Simmonds
|What Else Can You Do with Android?
|[[Media:android-inside.tar.gz|android-inside.tar.gz]]
|}

== Instructions for Presenters ==
Please create a link in the table for your presentation, copying the style of other links or as follows:

<nowiki>[[Media:name_of_your_presentation.pdf | name_of_your_presentation.pdf]]</nowiki> Note the supported mime types on the [[Special:Upload | Upload file]] page. The latter example uses a PDF example, your file type can be different.

(You may need to create an account in order to edit the wiki or upload files.)

When you have created the link, click on it to upload the file containing your slides.

File:Rt latency cache and locks.pdf

2010-10-28T15:26:17Z

Frowand: ELCE 2010 presentation by Frank Rowand

ELCE 2010 presentation by Frank Rowand

Real Time

2010-04-19T22:24:57Z

Frowand: /* Documents */

This page has information about Real-time usage of Linux. Also this page has information about timing systems for Linux. This is of interest to CE Linux Forum members, because many consumer electronics products have realtime requirements (e.g. in the areas of multi-media presentation, or communications)

== Real Time Wiki ==
* Please note that the primary source of information for Real Time Linux information is the new [http://rt.wiki.kernel.org/ RTWiki].

== Technology/Project pages ==
* [[Realtime Preemption]] - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
* [[Kernel Timer Systems]] - Various new proposals for changing the kernel timing system
* [[Soft IRQ Threads]] - Technology to put SoftIRQs in threads so they can be preempted.
** '' '''NOTE:''' Soft IRQ threads are now (Oct 2007) incorporated into the [[Realtime Preemption]] patch ''
* [[High Resolution Timers]] - A system to support timers with sub-jiffy resolution
* [[Variable Scheduling Timeouts]] - A system to support variable timeouts for periodic system activities (also known as Tickless)

== Documents ==
* [http://www.amazon.com/Building-Embedded-Linux-Systems-Yaghmour/dp/0596529686 Building Embedded Linux Systems, 2nd edition] discusses the realtime preemption patch.
* [http://tree.celinuxforum.org/CelfPubWiki/RTSpecDraft_5fR2 CELF Realtime Specification] (from 2004, so it's pretty old)
*Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - [[Media:Real-Time-Preemption-Patchset.pdf]]
* [[Realtime Testing Best Practices]] - a document to show recent testing results, and give hints for how different tests are conducted and what pitfalls to avoid.
* [http://free-electrons.com/articles/realtime/ Real time in embedded Linux systems]
* [http://www.celinux.org/elc08_presentations/Using_Real-Time_Linux.KlaasVanGend.ELC2008.pdf Using Real-Time Linux] - Presentation by Klaas van Gends at the ELC 2008. The [http://free-electrons.com/pub/video/2008/elc/elc2008-klaas-van-gend-using-real-time-linux.ogg video] is available
* Frank Rowand's series of talks
** ''Adventures in real-time performance tuning''
*** Part 1, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_1-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part1.ogv video] ELCE 2008 version
*** Part 2, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_2-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part2.ogv video] ELCE 2008 version
** Musings On Analysis of Measurements of a Real-Time Workload [http://tree.celinuxforum.org/CelfPubWiki/ELC2009Presentations?action=AttachFile&do=get&target=musings_on_analysis_of_measurements_of_a_real-time_workload.pdf slides] ELC 2009 version and [http://free-electrons.com/pub/video/2009/elce/elce2009-rowand-measurement-diagnostic-tools.ogv video]
** Real-Time Linux Failure [[Media:Real_time_linux_failure.pdf|slides]] ELC 2010 version
* ''Real-time vs real-fast, how to choose'', conference given by Paul E. McKenney at the Ottawa Linux Symposium 2008. [http://ols.fedoraproject.org/OLS/Reprints-2008/mckenney-reprint.pdf Paper] and [http://free-electrons.com/pub/video/2008/ols/ols2008-paul-mckenney-real-time-vs-real-fast.ogg video]

== Further Open Source Projects ==
* [http://www.xenomai.org Xenomai] - Real-time development framework, closely cooperating with the Linux kernel. Among other features, it provides a migration path from various RTOSes like VxWorks, PSOS+, etc. to Linux based on so-called skins.

[[Category:Real Time]]

Real Time

2010-04-13T15:41:03Z

Frowand: /* Documents */

This page has information about Real-time usage of Linux. Also this page has information about timing systems for Linux. This is of interest to CE Linux Forum members, because many consumer electronics products have realtime requirements (e.g. in the areas of multi-media presentation, or communications)

== Real Time Wiki ==
* Please note that the primary source of information for Real Time Linux information is the new [http://rt.wiki.kernel.org/ RTWiki].

== Technology/Project pages ==
* [[Realtime Preemption]] - Ingo Molnar's patchset to add realtime preemption to the 2.6 Linux kernel
* [[Kernel Timer Systems]] - Various new proposals for changing the kernel timing system
* [[Soft IRQ Threads]] - Technology to put SoftIRQs in threads so they can be preempted.
** '' '''NOTE:''' Soft IRQ threads are now (Oct 2007) incorporated into the [[Realtime Preemption]] patch ''
* [[High Resolution Timers]] - A system to support timers with sub-jiffy resolution
* [[Variable Scheduling Timeouts]] - A system to support variable timeouts for periodic system activities (also known as Tickless)

== Documents ==
* [http://www.amazon.com/Building-Embedded-Linux-Systems-Yaghmour/dp/0596529686 Building Embedded Linux Systems, 2nd edition] discusses the realtime preemption patch.
* [http://tree.celinuxforum.org/CelfPubWiki/RTSpecDraft_5fR2 CELF Realtime Specification] (from 2004, so it's pretty old)
*Realtime Preemption presentation by Manas at the 2005 CELF Technical Conference - [[Media:Real-Time-Preemption-Patchset.pdf]]
* [[Realtime Testing Best Practices]] - a document to show recent testing results, and give hints for how different tests are conducted and what pitfalls to avoid.
* [http://free-electrons.com/articles/realtime/ Real time in embedded Linux systems]
* [http://www.celinux.org/elc08_presentations/Using_Real-Time_Linux.KlaasVanGend.ELC2008.pdf Using Real-Time Linux] - Presentation by Klaas van Gends at the ELC 2008. The [http://free-electrons.com/pub/video/2008/elc/elc2008-klaas-van-gend-using-real-time-linux.ogg video] is available
* Frank Rowand's series of talks
** ''Adventures in real-time performance tuning''
*** Part 1, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_1-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part1.ogv video] ELCE 2008 version
*** Part 2, [http://tree.celinuxforum.org/CelfPubWiki/ELCEurope2008Presentations?action=AttachFile&do=get&target=adventures_in_real_time_performance_tuning_part_2-no_hidden.pdf slides] and [http://free-electrons.com/pub/video/2008/elce/elce2008-rowand-adventures-real-time-part2.ogv video] ELCE 2008 version
** Musings On Analysis of Measurements of a Real-Time Workload [http://tree.celinuxforum.org/CelfPubWiki/ELC2009Presentations?action=AttachFile&do=get&target=musings_on_analysis_of_measurements_of_a_real-time_workload.pdf slides] ELC 2009 version and [http://free-electrons.com/pub/video/2009/elce/elce2009-rowand-measurement-diagnostic-tools.ogv video]
* ''Real-time vs real-fast, how to choose'', conference given by Paul E. McKenney at the Ottawa Linux Symposium 2008. [http://ols.fedoraproject.org/OLS/Reprints-2008/mckenney-reprint.pdf Paper] and [http://free-electrons.com/pub/video/2008/ols/ols2008-paul-mckenney-real-time-vs-real-fast.ogg video]

== Further Open Source Projects ==
* [http://www.xenomai.org Xenomai] - Real-time development framework, closely cooperating with the Linux kernel. Among other features, it provides a migration path from various RTOSes like VxWorks, PSOS+, etc. to Linux based on so-called skins.

[[Category:Real Time]]