linux-toradex.git/mm, branch v2.6.38-rc2

memcg: correctly order reading PCG_USED and pc->mem_cgroup

2011-01-21T01:02:06+00:00

The placement of the read-side barrier is confused: the writer first
sets pc->mem_cgroup, then PCG_USED.  The read-side barrier has to be
between testing PCG_USED and reading pc->mem_cgroup.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Daisuke Nishimura 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: fix truncate_setsize() comment

2011-01-21T01:02:06+00:00

Contrary to what the comment says, truncate_setsize() should be called
*before* filesystem truncated blocks.

Signed-off-by: Jan Kara 
Cc: Christoph Hellwig 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: fix rmdir, force_empty with THP

2011-01-21T01:02:06+00:00

Now, when THP is enabled, memcg's rmdir() function is broken because
move_account() for THP page is not supported.

This will cause account leak or -EBUSY issue at rmdir().
This patch fixes the issue by supporting move_account() THP pages.

Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Balbir Singh 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: fix LRU accounting with THP

2011-01-21T01:02:06+00:00

memory cgroup's LRU stat should take care of size of pages because
Transparent Hugepage inserts hugepage into LRU.  If this value is the
number wrong, memory reclaim will not work well.

Note: only head page of THP's huge page is linked into LRU.

Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Balbir Singh 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: fix USED bit handling at uncharge in THP

2011-01-21T01:02:06+00:00

Now, under THP:

at charge:
  - PageCgroupUsed bit is set to all page_cgroup on a hugepage.
    ....set to 512 pages.
at uncharge
  - PageCgroupUsed bit is unset on the head page.

So, some pages will remain with "Used" bit.

This patch fixes that Used bit is set only to the head page.
Used bits for tail pages will be set at splitting if necessary.

This patch adds this lock order:
   compound_lock() -> page_cgroup_move_lock().

[akpm@linux-foundation.org: fix warning]
Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Balbir Singh 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: modify accounting function for supporting THP better

2011-01-21T01:02:05+00:00

mem_cgroup_charge_statisics() was designed for charging a page but now, we
have transparent hugepage.  To fix problems (in following patch) it's
required to change the function to get the number of pages as its
arguments.

The new function gets following as argument.
  - type of page rather than 'pc'
  - size of page which is accounted.

Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Balbir Singh 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: compaction: prevent division-by-zero during user-requested compaction

2011-01-21T01:02:05+00:00

Up until 3e7d344 ("mm: vmscan: reclaim order-0 and use compaction instead
of lumpy reclaim"), compaction skipped calculating the fragmentation index
of a zone when compaction was explicitely requested through the procfs
knob.

However, when compaction_suitable was introduced, it did not come with an
extra check for order == -1, set on explicit compaction requests, and
passed this order on to the fragmentation index calculation, where it
overshifts the number of requested pages, leading to a division by zero.

This patch makes sure that order == -1 is recognized as the flag it is
rather than passing it along as valid order parameter.

[akpm@linux-foundation.org: add comment, per Mel]
Signed-off-by: Johannes Weiner 
Reviewed-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/vmscan.c: remove duplicate include of compaction.h

2011-01-21T01:02:05+00:00

Signed-off-by: Jesper Juhl 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: fix memblock_is_region_memory()

2011-01-21T01:02:05+00:00

memblock_is_region_memory() uses reserved memblocks to search for the
given region, while it should use the memory memblocks.

I encountered the problem with OMAP's framebuffer ram allocation.
Normally the ram is allocated dynamically, and this function is not
called.  However, if we want to pass the framebuffer from the bootloader
to the kernel (to retain the boot image), this function is used to check
the validity of the kernel parameters for the framebuffer ram area.

Signed-off-by: Tomi Valkeinen 
Acked-by: Yinghai Lu 
Cc: Benjamin Herrenschmidt 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: keep highpte mapped until it is no longer needed

2011-01-21T01:02:05+00:00

Two users reported THP-related crashes on 32-bit x86 machines.  Their oops
reports indicated an invalid pte, and subsequent code inspection showed
that the highpte is actually used after unmap.

The fix is to unmap the pte only after all operations against it are
finished.

Signed-off-by: Johannes Weiner 
Reported-by: Ilya Dryomov 
Reported-by: werner 
Cc: Andrea Arcangeli 
Tested-by: Ilya Dryomov 
Tested-by: Steven Rostedt 
Signed-off-by: Linus Torvalds