Kernel dynamic memory analysis - Revision history

Ezequiel: /* The size command */

2013-01-17T18:17:09Z

‎The size command

2012-12-18T10:21:36Z

‎Pitfall: wrongly reported allocation (and how to fix it)

2012-11-24T15:19:39Z

‎Nacked

2012-11-24T14:35:22Z

‎Visualization

2012-11-24T14:31:11Z

‎Static footprint

2012-11-24T14:25:35Z

2012-11-24T14:24:45Z

‎Visualization

2012-11-23T12:31:31Z

Remove old image

2012-11-23T12:31:08Z

Remove old image

2012-11-21T00:09:28Z

‎Slab account

@@ Line 217: / Line 217: @@
   [...]
-Here we see a more detailed description about each section size. Note the appearence of a .rodata (read-only data) section, of 2k byte large. This section is composed of read-only variables (e.g. marked const) that are not accounted by the standard ''size'' format.
+Here we see a more detailed description about each section size. Note the appearence of a .rodata (read-only data) section, of 2k byte large. This section is composed of read-only variables (e.g. marked const) that are not accounted under the data column, but rather as text by the standard ''size'' format.
-−
-We can conclude that standard ''size'' format gives an incomplete picture of the compiled object.
 To add even more confusion to this picture, gcc can decide (at his own will) to put inside .rodata section symbols not marked as const. These symbols are not written by anyone, and gcc considers them as read-only (pretty smart, uh?). This means you can have a .rodata section bigger than what you expected to have.

@@ Line 595: / Line 595: @@
   char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
+  {
-	/* code removed */
+        /* code removed */
-	p = kmalloc(len+1, gfp);
+        p = kmalloc(len+1, gfp);
 And trace_analyze produces the account file

@@ Line 838: / Line 838: @@
    [PATCH v2] Makefile: Add option to disable gcc automatic inlining
    https://lkml.org/lkml/2012/10/7/209
 == Recommendations for reductions ==

@@ Line 748: / Line 748: @@
 === Current dynamic footprint ===
 === Static footprint ===
-This is a ring chart showing static usage, start branch is 'fs' and the kernel is configured with ext2, ubifs, jffs2.
+This ring chart shows static usage, start branch is 'fs' and the kernel is configured with ext2, ubifs, jffs2.
 Script command line is:

← Older revision		Revision as of 14:31, 24 November 2012
Line 750:		Line 750:

	=== Static footprint ===		=== Static footprint ===
		+
		+	This is a ring chart showing static usage, start branch is 'fs' and the kernel is configured with ext2, ubifs, jffs2.
		+	Script command line is:
		+
		+	$ trace_analyze.py -f kmem.log -k ../linux-mtd/ -a static -b fs -r fs-static.png
		+
		+	[[File:fs_static.png\|800px]]

	== Mainline status ==		== Mainline status ==

@@ Line 745: / Line 745: @@
 We will use matplotlib with its Wedge api to create a ring chart (similar to gnome baobab).
-We'll get something like this (this is '''very''' minimal kernel run):
+We'll get something like this:
 == Current dynamic footprint ==

@@ Line 883: / Line 883: @@
 == Slab account ==
-Slab accounting is another method of
+Slab accounting is another method of obtaining allocation-related information about the kernel.
 This is the version of the patch for 3.6:
 * [[File:0001-mm-sl-aou-b-Add-slab-accounting-debugging-feature-v3.6.patch]]