This is a note to let you know that I've just added the patch titled
memcg: fix Bad page state after replace_page_cache
to the 3.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
memcg-fix-bad-page-state-after-replace_page_cache.patch
and it can be found in the queue-3.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 9b7f43afd417a6feb80841d30ced4051c362eb5d Mon Sep 17 00:00:00 2001
From: Hugh Dickins <[email protected]>
Date: Wed, 18 Apr 2012 23:34:46 -0700
Subject: memcg: fix Bad page state after replace_page_cache
From: Hugh Dickins <[email protected]>
commit 9b7f43afd417a6feb80841d30ced4051c362eb5d upstream.
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 <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
mm/memcontrol.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3350,6 +3350,7 @@ void mem_cgroup_replace_page_cache(struc
* the newpage may be on LRU(or pagevec for LRU) already. We lock
* LRU while we overwrite pc->mem_cgroup.
*/
+ pc = lookup_page_cgroup(newpage);
__mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true);
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.3/memcg-fix-bad-page-state-after-replace_page_cache.patch
queue-3.3/hugetlb-fix-race-condition-in-hugetlb_fault.patch
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