diff options
| author | Chris Down <chris@chrisdown.name> | 2020-03-21 18:22:20 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-25 08:25:57 +0100 |
| commit | 77c4bc4bf612dbb293b94655599fe494174aedea (patch) | |
| tree | c35e4c0367d3500630b091c374b3ccb4c63d5841 /mm/memcontrol.c | |
| parent | ceca26903bd744a09e3f176280f1f5475c44c319 (diff) | |
mm, memcg: fix corruption on 64-bit divisor in memory.high throttling
commit d397a45fc741c80c32a14e2de008441e9976f50c upstream.
Commit 0e4b01df8659 had a bunch of fixups to use the right division
method. However, it seems that after all that it still wasn't right --
div_u64 takes a 32-bit divisor.
The headroom is still large (2^32 pages), so on mundane systems you
won't hit this, but this should definitely be fixed.
Fixes: 0e4b01df8659 ("mm, memcg: throttle allocators when failing reclaim over memory.high")
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: <stable@vger.kernel.org> [5.4.x+]
Link: http://lkml.kernel.org/r/80780887060514967d414b3cd91f9a316a16ab98.1584036142.git.chris@chrisdown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c794f2aafefe..6ef90255a3e0 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2456,7 +2456,7 @@ void mem_cgroup_handle_over_high(void) */ clamped_high = max(high, 1UL); - overage = div_u64((u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT, + overage = div64_u64((u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT, clamped_high); penalty_jiffies = ((u64)overage * overage * HZ) |