The patch titled
Subject: memcg: flush stats non-atomically in mem_cgroup_wb_stats()
has been added to the -mm mm-unstable branch. Its filename is
memcg-flush-stats-non-atomically-in-mem_cgroup_wb_stats.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memcg-flush-stats-non-atomically-in-mem_cgroup_wb_stats.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: memcg: flush stats non-atomically in mem_cgroup_wb_stats()
Date: Fri, 21 Apr 2023 17:40:17 +0000
The previous patch moved the wb_over_bg_thresh()->mem_cgroup_wb_stats()
code path in wb_writeback() outside the lock section. We no longer need
to flush the stats atomically. Flush the stats non-atomically.
Link: https://lkml.kernel.org/r/20230421174020.2994750-3-yosryahmed@xxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Reviewed-by: Michal Koutný <mkoutny@xxxxxxxx>
Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
--- a/mm/memcontrol.c~memcg-flush-stats-non-atomically-in-mem_cgroup_wb_stats
+++ a/mm/memcontrol.c
@@ -4656,11 +4656,7 @@ void mem_cgroup_wb_stats(struct bdi_writ
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
struct mem_cgroup *parent;
- /*
- * wb_writeback() takes a spinlock and calls
- * wb_over_bg_thresh()->mem_cgroup_wb_stats(). Do not sleep.
- */
- mem_cgroup_flush_stats_atomic();
+ mem_cgroup_flush_stats();
*pdirty = memcg_page_state(memcg, NR_FILE_DIRTY);
*pwriteback = memcg_page_state(memcg, NR_WRITEBACK);
_
Patches currently in -mm which might be from yosryahmed@xxxxxxxxxx are
memcg-use-seq_buf_do_printk-with-mem_cgroup_print_oom_meminfo.patch
memcg-dump-memorystat-during-cgroup-oom-for-v1.patch
writeback-move-wb_over_bg_thresh-call-outside-lock-section.patch
memcg-flush-stats-non-atomically-in-mem_cgroup_wb_stats.patch
memcg-calculate-root-usage-from-global-state.patch
memcg-remove-mem_cgroup_flush_stats_atomic.patch
cgroup-remove-cgroup_rstat_flush_atomic.patch
