linux-toradex.git/mm/memcontrol.c, branch v3.4.5

memcg,thp: fix res_counter:96 regression

2012-05-19T17:10:27+00:00

Occasionally, testing memcg's move_charge_at_immigrate on rc7 shows
a flurry of hundreds of warnings at kernel/res_counter.c:96, where
res_counter_uncharge_locked() does WARN_ON(counter->usage < val).

The first trace of each flurry implicates __mem_cgroup_cancel_charge()
of mc.precharge, and an audit of mc.precharge handling points to
mem_cgroup_move_charge_pte_range()'s THP handling in commit 12724850e806
("memcg: avoid THP split in task migration").

Checking !mc.precharge is good everywhere else, when a single page is to
be charged; but here the "mc.precharge -= HPAGE_PMD_NR" likely to
follow, is liable to result in underflow (a lot can change since the
precharge was estimated).

Simply check against HPAGE_PMD_NR: there's probably a better
alternative, trying precharge for more, splitting if unsuccessful; but
this one-liner is safer for now - no kernel/res_counter.c:96 warnings
seen in 26 hours.

Signed-off-by: Hugh Dickins 
Signed-off-by: Linus Torvalds

memcg: free spare array to avoid memory leak

2012-05-10T22:06:44+00:00

When the last event is unregistered, there is no need to keep the spare
array anymore.  So free it to avoid memory leak.

Signed-off-by: Sha Zhengju 
Acked-by: KAMEZAWA Hiroyuki 
Reviewed-by: Kirill A. Shutemov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: move pc lookup point to commit_charge()

2012-04-26T04:22:35+00:00

None of the callsites actually need the page_cgroup descriptor
themselves, so just pass the page and do the look up in there.

We already had two bugs (6568d4a 'mm: memcg: update the correct soft
limit tree during migration' and 'memcg: fix Bad page state after
replace_page_cache') where the passed page and pc were not referring
to the same page frame.

Signed-off-by: Johannes Weiner 
Acked-by: Hugh Dickins 
Signed-off-by: Linus Torvalds

memcg: fix Bad page state after replace_page_cache

2012-04-19T06:40:57+00:00

My 9ce70c0240d0 "memcg: fix deadlock by inverting lrucare nesting" put a
nasty little bug into v3.3's version of mem_cgroup_replace_page_cache(),
sometimes used for FUSE.  Replacing __mem_cgroup_commit_charge_lrucare()
by __mem_cgroup_commit_charge(), I used the "pc" pointer set up earlier:
but it's for oldpage, and needs now to be for newpage.  Once oldpage was
freed, its PageCgroupUsed bit (cleared above but set again here) caused
"Bad page state" messages - and perhaps worse, being missed from newpage.
(I didn't find this by using FUSE, but in reusing the function for tmpfs.)

Signed-off-by: Hugh Dickins 
Cc: stable@vger.kernel.org [v3.3 only]
Signed-off-by: Linus Torvalds

memcg: do not open code accesses to res_counter members

2012-04-12T20:12:12+00:00

We should use the accessor res_counter_read_u64 for that.

Although a purely cosmetic change is sometimes better delayed, to avoid
conflicting with other people's work, we are starting to have people
touching this code as well, and reproducing the open code behavior
because that's the standard =)

Time to fix it, then.

Signed-off-by: Glauber Costa 
Cc: Johannes Weiner 
Acked-by: Michal Hocko 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: fix broken boolen expression

2012-04-12T20:12:11+00:00

action != CPU_DEAD || action != CPU_DEAD_FROZEN is always true.

Signed-off-by: Kirill A. Shutemov 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: thp: fix up pmd_trans_unstable() locations

2012-03-29T00:14:35+00:00

pmd_trans_unstable() should be called before pmd_offset_map() in the
locations where the mmap_sem is held for reading.

Signed-off-by: Andrea Arcangeli 
Cc: Mel Gorman 
Cc: Hugh Dickins 
Cc: Larry Woodman 
Cc: Ulrich Obergfell 
Cc: Rik van Riel 
Cc: Mark Salter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: avoid THP split in task migration

2012-03-22T00:55:02+00:00

Currently we can't do task migration among memory cgroups without THP
split, which means processes heavily using THP experience large overhead
in task migration.  This patch introduces the code for moving charge of
THP and makes THP more valuable.

Signed-off-by: Naoya Horiguchi 
Acked-by: Hillf Danton 
Cc: Andrea Arcangeli 
Acked-by: KAMEZAWA Hiroyuki 
Cc: David Rientjes 
Cc: Daisuke Nishimura 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: clean up existing move charge code

2012-03-22T00:55:02+00:00

- Replace lengthy function name is_target_pte_for_mc() with a shorter
  one in order to avoid ugly line breaks.

- explicitly use MC_TARGET_* instead of simply using integers.

Signed-off-by: Naoya Horiguchi 
Cc: Andrea Arcangeli 
Cc: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Hillf Danton 
Cc: David Rientjes 
Acked-by: Hillf Danton 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memcontrol.c: remove unnecessary 'break' in mem_cgroup_read()

2012-03-22T00:55:02+00:00

Signed-off-by: Jie Liu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds