The patch titled
Subject: vmscan: memcg: sleep when flushing stats during reclaim
has been added to the -mm mm-unstable branch. Its filename is
vmscan-memcg-sleep-when-flushing-stats-during-reclaim.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/vmscan-memcg-sleep-when-flushing-stats-during-reclaim.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Subject: vmscan: memcg: sleep when flushing stats during reclaim
Date: Thu, 30 Mar 2023 19:18:00 +0000
Memory reclaim is a sleepable context. Flushing is an expensive operaiton
that scales with the number of cpus and the number of cgroups in the
system, so avoid doing it atomically unnecessarily. This can slow down
reclaim code if flushing stats is taking too long, but there is already
multiple cond_resched()'s in reclaim code.
Link: https://lkml.kernel.org/r/20230330191801.1967435-8-yosryahmed@xxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michal Koutný <mkoutny@xxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Vasily Averin <vasily.averin@xxxxxxxxx>
Cc: Zefan Li <lizefan.x@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/vmscan.c~vmscan-memcg-sleep-when-flushing-stats-during-reclaim
+++ a/mm/vmscan.c
@@ -2861,7 +2861,7 @@ static void prepare_scan_count(pg_data_t
* Flush the memory cgroup stats, so that we read accurate per-memcg
* lruvec stats for heuristics.
*/
- mem_cgroup_flush_stats_atomic();
+ mem_cgroup_flush_stats();
/*
* Determine the scan balance between anon and file LRUs.
_
Patches currently in -mm which might be from yosryahmed@xxxxxxxxxx are
cgroup-rename-cgroup_rstat_flush_irqsafe-to-atomic.patch
memcg-rename-mem_cgroup_flush_stats_delayed-to-ratelimited.patch
memcg-do-not-flush-stats-in-irq-context.patch
memcg-replace-stats_flush_lock-with-an-atomic.patch
memcg-sleep-during-flushing-stats-in-safe-contexts.patch
workingset-memcg-sleep-when-flushing-stats-in-workingset_refault.patch
vmscan-memcg-sleep-when-flushing-stats-during-reclaim.patch
memcg-do-not-modify-rstat-tree-for-zero-updates.patch
