From: Eric Dumazet <eric.dumazet@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>
Subject: [PATCH] percpu: add a schedule point in pcpu_balance_workfn()
Date: Fri, 23 Feb 2018 08:12:42 -0800 [thread overview]
Message-ID: <1519402362.55655.70.camel@gmail.com> (raw)
From: Eric Dumazet <edumazet@google.com>
When a large BPF percpu map is destroyed, I have seen
pcpu_balance_workfn() holding cpu for hundreds of milliseconds.
On KASAN config and 112 hyperthreads, average time to destroy a chunk
is ~4 ms.
[ 2489.841376] destroy chunk 1 in 4148689 ns
...
[ 2490.093428] destroy chunk 32 in 4072718 ns
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
mm/percpu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/percpu.c b/mm/percpu.c
index 50e7fdf84055151d8c7e8bb220f7a73e96b7f3e4..d40dfb597ffce2656220257f0227219ab917135b 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1600,6 +1600,7 @@ static void pcpu_balance_workfn(struct work_struct *work)
spin_unlock_irq(&pcpu_lock);
}
pcpu_destroy_chunk(chunk);
+ cond_resched();
}
/*
next reply other threads:[~2018-02-23 16:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-23 16:12 Eric Dumazet [this message]
2018-02-23 16:53 ` [PATCH] percpu: add a schedule point in pcpu_balance_workfn() Tejun Heo
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