The patch titled
has been added to the -mm tree. Its filename is
mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim-fix.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim-fix.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim-fix.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff -puN mm/memcontrol.c~mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim-fix mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim-fix
+++ a/mm/memcontrol.c
@@ -915,7 +915,7 @@ struct mem_cgroup *mem_cgroup_iter(struc
* might block it. So we clear iter->position right
* away.
*/
- cmpxchg(&iter->position, pos, NULL);
+ (void)cmpxchg(&iter->position, pos, NULL);
}
}
@@ -962,7 +962,12 @@ struct mem_cgroup *mem_cgroup_iter(struc
}
if (reclaim) {
- cmpxchg(&iter->position, pos, memcg);
+ /*
+ * The position could have already been updated by a competing
+ * thread, so check that the value hasn't changed since we read
+ * it to avoid reclaiming from the same cgroup twice.
+ */
+ (void)cmpxchg(&iter->position, pos, memcg);
/*
* pairs with css_tryget when dereferencing iter->position
_
Patches currently in -mm which might be from vdavydov@xxxxxxxxxxxxx are
mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim.patch
mm-memcontrol-fix-possible-memcg-leak-due-to-interrupted-reclaim-fix.patch
revert-kernfs-do-not-account-ino_ida-allocations-to-memcg.patch
revert-gfp-add-__gfp_noaccount.patch
memcg-only-account-kmem-allocations-marked-as-__gfp_account.patch
slab-add-slab_account-flag.patch
vmalloc-allow-to-account-vmalloc-to-memcg.patch
account-certain-kmem-allocations-to-memcg.patch
vmscan-do-not-force-scan-file-lru-if-its-absolute-size-is-small.patch
vmscan-do-not-force-scan-file-lru-if-its-absolute-size-is-small-v2.patch
memcg-do-not-allow-to-disable-tcp-accounting-after-limit-is-set.patch
mm-add-page_check_address_transhuge-helper.patch
mm-add-page_check_address_transhuge-helper-fix.patch
mm-memcontrol-allow-to-disable-kmem-accounting-for-cgroup2.patch
net-drop-tcp_memcontrolc.patch
mm-memcontrol-charge-swap-to-cgroup2.patch
mm-vmscan-pass-memcg-to-get_scan_count.patch
mm-memcontrol-replace-mem_cgroup_lruvec_online-with-mem_cgroup_online.patch
swaph-move-memcg-related-stuff-to-the-end-of-the-file.patch
mm-vmscan-do-not-scan-anon-pages-if-memcg-swap-limit-is-hit.patch
mm-free-swap-cache-aggressively-if-memcg-swap-is-full.patch
documentation-cgroup-add-memoryswapcurrentmax-description.patch
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