The patch titled
Subject: mm/vmstat.c: erase latency in vmstat_shepherd
has been added to the -mm tree. Its filename is
mm-vmstatc-erase-latency-in-vmstat_shepherd.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-vmstatc-erase-latency-in-vmstat_shepherd.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-vmstatc-erase-latency-in-vmstat_shepherd.patch
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------------------------------------------------------
From: Jiang Biao <benbjiang@xxxxxxxxxxx>
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@xxxxxxxxxxx
Signed-off-by: Jiang Biao <benbjiang@xxxxxxxxxxx>
Reported-by: Bin Lai <robinlai@xxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmstat.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/vmstat.c~mm-vmstatc-erase-latency-in-vmstat_shepherd
+++ a/mm/vmstat.c
@@ -1973,6 +1973,8 @@ 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();
}
put_online_cpus();
_
Patches currently in -mm which might be from benbjiang@xxxxxxxxxxx are
mm-vmstatc-erase-latency-in-vmstat_shepherd.patch
