Re: [RFC PATCH] io-wq: kill cpu hog worker

From: Jens Axboe
Date: Tue Dec 24 2019 - 11:13:49 EST


On 12/24/19 4:54 AM, Hillf Danton wrote:
>
> On Mon, 23 Dec 2019 08:15:00 -0700 Jens Axboe wrote:
>>
>> On 12/22/19 7:41 PM, Hillf Danton wrote:
>>>
>>> Reschedule the current IO worker if it is becoming a cpu hog.
>>
>> Might make more sense to put this a bit earlier, to avoid the
>> awkward lock juggle. In theory it shouldn't make a difference
>> if we do it _before_ doing new work, or _after_ doing work. We
>> should only be rescheduling if it's running for quite a while.
>>
>> How about putting it after the flushing of signals instead?
>
>
> All right, thanks.
>
> Hillf
> --->8---
> From: Hillf Danton <hdanton@xxxxxxxx>
> Subject: [RFC PATCH] io-wq: kill cpu hog worker
>
> Reschedule the current IO worker to cut the risk that it is becoming
> a cpu hog.
>
> Signed-off-by: Hillf Danton <hdanton@xxxxxxxx>
> ---
>
> --- a/fs/io-wq.c
> +++ b/fs/io-wq.c
> @@ -432,6 +432,8 @@ next:
> if (signal_pending(current))
> flush_signals(current);
>
> + cond_resched();
> +
> spin_lock_irq(&worker->lock);
> worker->cur_work = work;
> spin_unlock_irq(&worker->lock);
> --

That looks better, applied.

--
Jens Axboe