Re: [PATCH] percpu: add a schedule point in pcpu_balance_workfn()

From: Tejun Heo
Date: Fri Feb 23 2018 - 11:53:27 EST


On Fri, Feb 23, 2018 at 08:12:42AM -0800, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>

Applied to percpu/for-4.16-fixes.

Thank, Eric.

--
tejun