[PATCH v5 2/5] memcg: flush stats non-atomically in mem_cgroup_wb_stats()

Yosry Ahmed posted 5 patches 2 years, 7 months ago
[PATCH v5 2/5] memcg: flush stats non-atomically in mem_cgroup_wb_stats()
Posted by Yosry Ahmed 2 years, 7 months ago
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.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
---
 mm/memcontrol.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4b27e245a055..5e79fdf8442b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4648,11 +4648,7 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 	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);
-- 
2.40.0.634.g4ca3ef3211-goog
Re: [PATCH v5 2/5] memcg: flush stats non-atomically in mem_cgroup_wb_stats()
Posted by Tejun Heo 2 years, 7 months ago
On Fri, Apr 21, 2023 at 05:40:17PM +0000, Yosry Ahmed wrote:
> 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.
> 
> Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
> Reviewed-by: Michal Koutný <mkoutny@suse.com>
> Acked-by: Shakeel Butt <shakeelb@google.com>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun