Embedded linux status

Here is an outline for a presentation on the status of embedded Linux:

This is essentially User:Tim Bird's private collection of interesting notes about the status of embedded Linux. It tends to get updated right before a Linux conference.

Kernel
2.6.24: * kernel markers * security modules are gone

Interesting patches: * latency trace system (mcount support in the kernel, with multiple tracers) * Steven Rostedt's isolation and generalization of RT-preempts latency-trace system * mem_notify - allows processes to avoid the OOM killer * see http://lwn.net/Articles/266361/ * latencytop support (going into 2.6.25??) * see http://lwn.net/Articles/266153/ * kpagemap - finally accepted into 2.6.25?? (yes according to Matt Mackall)

Bootup Time

 * pre-linking
 * XIP
 * (see filesystem work)
 * KFT
 * embedded bootchart

System Size

 * SLUB vs. SLAB vs. SLOB
 * in 2.6.23 both SLUB and SLOB received some updates. Nick Piggins wants to know what the size difference is between SLOB And SLUB.  SLUB is on a track to replace SLAB.  (Although there is still ongoing discussion about performance regressions of SLUB on some database loads, on LKML beginning of Oct.)
 * [give SLOB vs. SLUB size numbers]
 * x86 SLOB yields 180K more runtime memory than SLOB
 * arm SLOB yields ??? more runtime memory than SLOB
 * Linux-tiny revival
 * squashfs - will it ever get mainlined

Security

 * smack is accepted into the Linux kernel
 * SELinux vs. AppArmor, TomoyoLinux and other path-based systems
 * Crispin Cowan (and other AppArmour developers) were layed off from Novell
 * See http://www.news.com/8301-13580_3-9796140-39.html

File Systems

 * Yaffs
 * squashfs
 * cramfs
 * jffs2
 * logfs

licensing
The 2.6 and 2.6.1 releases of the GNU C Library are licensed under the LGPL version 2.1, and GPL version 2.1 for the non-library programs included, or any later version. This means you are free to redistribute this version under the terms of the LGPL version 3 or the GPL 3, as well under as the version 2.1 terms of the 2.6 release. We expect that the next non-bug-fix release of the C Library will migrate to a newer LGPL version.
 * broo-ha-ha over GPL 3.0 has died down
 * kernel safe for now, what about libs??
 * glibc 2.6.1 Release note (http://sourceware.org/ml/libc-announce/2007/msg00001.html)
 * quote on LGPLv3:

middleware

 * DLNA summit

Tools

 * Tracing
 * Kprobes
 * SystemTap
 * generic trace layer
 * posted by David Wilder, in Sep 2007
 * Looks like a successor to relayfs (or abstraction on top of relayfs)
 * See http://lwn.net/Articles/249526/
 * Patch at: http://lwn.net/Articles/249868/
 * Markers
 * Added to Linus' tree on Oct. 19. (Should be in 2.6.24)


 * Toolchains

Distributions

 * OpenEmbedded
 * Embedded Debian
 * PokyLinux
 * Fedora for ARM
 * Ubuntu Mobile - really a stripped-down desktop distro

Industry organizations or projects

 * LiMo
 * Feb 4 - announced their Linux platform
 * see this LIMO press release
 * CELF
 * new ARM UMPC initiative:
 * See http://www.linuxworld.com/news/2007/100407-montavista-arm-linux-umpc.html?nlhtos=100507linuxalert1&