The patch titled
memcg-fix-deadlock-between-cpuset-and-memcg-fix
has been added to the -mm tree. Its filename is
memcg-fix-deadlock-between-cpuset-and-memcg-fix.patch
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------------------------------------------------------
Subject: memcg-fix-deadlock-between-cpuset-and-memcg-fix
From: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
We must clear "mc.moving_task" before waking up all waiters at the end of
task migration.
Otherwise, there can be a small race like:
mem_cgroup_clear_mc() | mem_cgroup_wait_acct_move()
---------------------------------+-----------------------------------
__mem_cgroup_clear_mc() |
wake_up_all() |
| prepare_to_wait()
| if (mc.moving_task) -> true
| schedule()
| -> noone wakes it up.
mc.moving_task = NULL |
Signed-off-by: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
Cc: Ben Blum <bblum@xxxxxxxxxxxxxx>
Cc: Miao Xie <miaox@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@xxxxxxxxx>
Cc: Balbir Singh <balbir@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff -puN mm/memcontrol.c~memcg-fix-deadlock-between-cpuset-and-memcg-fix mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-fix-deadlock-between-cpuset-and-memcg-fix
+++ a/mm/memcontrol.c
@@ -4756,12 +4756,16 @@ static void mem_cgroup_clear_mc(void)
{
struct mem_cgroup *from = mc.from;
+ /*
+ * we must clear moving_task before waking up waiters at the end of
+ * task migration.
+ */
+ mc.moving_task = NULL;
__mem_cgroup_clear_mc();
spin_lock(&mc.lock);
mc.from = NULL;
mc.to = NULL;
spin_unlock(&mc.lock);
- mc.moving_task = NULL;
mem_cgroup_end_move(from);
}
_
Patches currently in -mm which might be from nishimura@xxxxxxxxxxxxxxxxx are
thp-transhuge-memcg-commit-tail-pages-at-charge.patch
thp-compound_trans_order-fix.patch
memcg-add-page_cgroup-flags-for-dirty-page-tracking.patch
memcg-document-cgroup-dirty-memory-interfaces.patch
memcg-document-cgroup-dirty-memory-interfaces-fix.patch
memcg-create-extensible-page-stat-update-routines.patch
memcg-add-lock-to-synchronize-page-accounting-and-migration.patch
memcg-fix-unit-mismatch-in-memcg-oom-limit-calculation.patch
memcg-fix-deadlock-between-cpuset-and-memcg.patch
memcg-fix-deadlock-between-cpuset-and-memcg-fix.patch
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