From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, chris@chrisdown.name, guro@fb.com,
hannes@cmpxchg.org, linux-mm@kvack.org, mhocko@kernel.org,
mm-commits@vger.kernel.org, natechancellor@gmail.com,
stable@vger.kernel.org, tj@kernel.org,
torvalds@linux-foundation.org
Subject: [patch 04/10] mm, memcg: fix corruption on 64-bit divisor in memory.high throttling
Date: Sat, 21 Mar 2020 18:22:20 -0700 [thread overview]
Message-ID: <20200322012220.Y-EvF7Agt%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200321181954.c0564dfd5514cd742b534884@linux-foundation.org>
From: Chris Down <chris@chrisdown.name>
Subject: mm, memcg: fix corruption on 64-bit divisor in memory.high throttling
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.
Link: http://lkml.kernel.org/r/80780887060514967d414b3cd91f9a316a16ab98.1584036142.git.chris@chrisdown.name
Fixes: 0e4b01df8659 ("mm, memcg: throttle allocators when failing reclaim over memory.high")
Signed-off-by: Chris Down <chris@chrisdown.name>
Reported-by: Johannes Weiner <hannes@cmpxchg.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+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memcontrol.c~mm-memcg-fix-corruption-on-64-bit-divisor-in-memoryhigh-throttling
+++ a/mm/memcontrol.c
@@ -2339,7 +2339,7 @@ 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)
_
next prev parent reply other threads:[~2020-03-22 1:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-22 1:19 incoming Andrew Morton
2020-03-22 1:22 ` [patch 01/10] memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event Andrew Morton
2020-03-22 1:22 ` [patch 02/10] mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case Andrew Morton
2020-03-22 1:22 ` [patch 03/10] page-flags: fix a crash at SetPageError(THP_SWAP) Andrew Morton
2020-03-22 1:22 ` Andrew Morton [this message]
2020-03-22 1:22 ` [patch 05/10] mm, memcg: throttle allocators based on ancestral memory.high Andrew Morton
2020-03-22 1:22 ` [patch 06/10] mm: do not allow MADV_PAGEOUT for CoW pages Andrew Morton
2020-03-22 1:22 ` [patch 07/10] epoll: fix possible lost wakeup on epoll_ctl() path Andrew Morton
2020-03-22 1:22 ` [patch 08/10] mm/mmu_notifier: silence PROVE_RCU_LIST warnings Andrew Morton
2020-03-22 1:22 ` [patch 09/10] mm, slub: prevent kmalloc_node crashes and memory leaks Andrew Morton
2020-03-22 1:22 ` [patch 10/10] x86/mm: split vmalloc_sync_all() Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200322012220.Y-EvF7Agt%akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=chris@chrisdown.name \
--cc=guro@fb.com \
--cc=hannes@cmpxchg.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mm-commits@vger.kernel.org \
--cc=natechancellor@gmail.com \
--cc=stable@vger.kernel.org \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox