Commit accd4f36 authored Feb 23, 2018 by Eric Dumazet Committed by Tejun Heo Feb 23, 2018

percpu: add a schedule point in pcpu_balance_workfn()



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

parent 554fef1c

mm/percpu.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1610,6 +1610,7 @@ static void pcpu_balance_workfn(struct work_struct *work)
		spin_unlock_irq(&pcpu_lock);
		}
		pcpu_destroy_chunk(chunk);
		cond_resched();
		}

		/*