Commit Graph

1 Commits

Author SHA1 Message Date
Alexander Nyberg 4855b811a1 debugging: keep track of page owners
akpm: Alex's ancient page-owner tracking code, resurrected yet
      again.  Someone(tm) should mainline this.  Please see Ingo's
      thoughts at https://lkml.org/lkml/2009/4/1/137.

PAGE_OWNER tracks free pages by setting page->order to -1.  However, it is
set during __free_pages() which is not the only free path as
__pagevec_free() and free_compound_page() do not go through __free_pages().
 This leads to a situation where free pages are visible in page_owner
which is confusing and might be interpreted as a memory leak.

This patch sets page->owner when PageBuddy is set.  It also prints a
warning to the kernel log if a free page is found that does not appear free
to PAGE_OWNER.  This should be considered a fix to
page-owner-tracking-leak-detector.patch.

This only applies to -mm as PAGE_OWNER is not in mainline.

[mel@csn.ul.ie: print out PAGE_OWNER statistics in relation to fragmentation avoidance]
[mel.ul.ie: allow PAGE_OWNER to be set on any architecture]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Laura Abbott <lauraa@codeaurora.org>
From: Dave Hansen <dave@linux.vnet.ibm.com>
Subject: debugging-keep-track-of-page-owners-fix

Updated 12/4/2012 - should apply to 3.7 kernels.  I did a quick
sniff-test to make sure that this boots and produces some sane
output, but it's not been exhaustively tested.

 * Moved file over to debugfs (no reason to keep polluting /proc)
 * Now using generic stack tracking infrastructure
 * Added check for MIGRATE_CMA pages to explicitly count them
   as movable.

The new snprint_stack_trace() probably belongs in its own patch
if this were to get merged, but it won't kill anyone as it stands.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Laura Abbott <lauraa@codeaurora.org>
From: Minchan Kim <minchan@kernel.org>
Subject: Fix wrong EOF compare

The C standards allows the character type char to be singed or unsinged,
depending on the platform and compiler. Most of systems uses signed char,
but those based on PowerPC and ARM processors typically use unsigned char.
This can lead to unexpected results when the variable is used to compare
with EOF(-1). It happens my ARM system and this patch fixes it.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
From: Andrew Morton <akpm@linux-foundation.org>
Subject: debugging-keep-track-of-page-owners-fix-2-fix

Reduce scope of `val', fix coding style

Cc: Minchan Kim <minchan@kernel.org>
From: Minchan Kim <minchan@kernel.org>
Subject: Enhance read_block of page_owner.c

The read_block reads char one by one until meeting two newline.
It's not good for the performance and current code isn't good shape
for readability.

This patch enhances speed and clean up.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
From: Andrew Morton <akpm@linux-foundation.org>
Subject: debugging-keep-track-of-page-owner-now-depends-on-stacktrace_support-fix

stomp sparse gfp_t warnings

Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
From: Dave Hansen <dave@linux.vnet.ibm.com>
Subject: PAGE_OWNER now depends on STACKTRACE_SUPPORT

One of the enhancements I made to the PAGE_OWNER code was to make
it use the generic stack trace support.  However, there are some
architectures that do not support it, like m68k.  So, make
PAGE_OWNER also depend on having STACKTRACE_SUPPORT.

This isn't ideal since it restricts the number of places
PAGE_OWNER runs now, but it at least hits all the major
architectures.

tree:   git://git.cmpxchg.org/linux-mmotm.git master
head:   83b324c5ff5cca85bbeb2ba913d465f108afe472
commit: 2a561c9d47c295ed91984c2b916a4dd450ee0279 [484/499] debugging-keep-track-of-page-owners-fix
config: make ARCH=m68k allmodconfig

All warnings:

warning: (PAGE_OWNER && STACK_TRACER && BLK_DEV_IO_TRACE && KMEMCHECK) selects STACKTRACE which has unmet direct dependencies (STACKTRACE_SUPPORT)

Change-Id: I8d9370733ead1c6a45bb034acc7aaf96e0901fea
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Git-commit: c6ca98b4acab6ae45cf0f9d93de9c717186e62cb
Git-repo: http://git.cmpxchg.org/cgit/linux-mmotm.git/
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
2014-03-28 13:33:08 -07:00