diff mbox series

[025/118] mm/vmstat.c: erase latency in vmstat_shepherd

Message ID 20210226011654.UO7WPPOjW%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [001/118] mm: make pagecache tagged lookups return only head pages | expand

Commit Message

Andrew Morton Feb. 26, 2021, 1:16 a.m. UTC
From: Jiang Biao <benbjiang@tencent.com>
Subject: mm/vmstat.c: erase latency in vmstat_shepherd

Many 100us+ latencies have been deteceted in vmstat_shepherd() on CPX
platform which has 208 logic cpus.  And vmstat_shepherd is queued every
second, which could make the case worse.

Add schedule point in vmstat_shepherd() to erase the latency.

Link: https://lkml.kernel.org/r/20210111035526.1511-1-benbjiang@tencent.com
Signed-off-by: Jiang Biao <benbjiang@tencent.com>
Reported-by: Bin Lai <robinlai@tencent.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

 mm/vmstat.c |    2 ++
 1 file changed, 2 insertions(+)
diff mbox series


--- a/mm/vmstat.c~mm-vmstatc-erase-latency-in-vmstat_shepherd
+++ a/mm/vmstat.c
@@ -1980,6 +1980,8 @@  static void vmstat_shepherd(struct work_
 		if (!delayed_work_pending(dw) && need_update(cpu))
 			queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
+		cond_resched();