Re: [PATCH] io_uring: remove wait loop spurious wakeups
From: Jens Axboe
Date: Mon Oct 07 2019 - 23:16:20 EST
On 10/7/19 5:18 PM, Pavel Begunkov (Silence) wrote:
> From: Pavel Begunkov <asml.silence@xxxxxxxxx>
>
> Any changes interesting to tasks waiting in io_cqring_wait() are
> commited with io_cqring_ev_posted(). However, io_ring_drop_ctx_refs()
> also tries to do that but with no reason, that means spurious wakeups
> every io_free_req() and io_uring_enter().
>
> Just use percpu_ref_put() instead.
Looks good, this is a leftover from when the ctx teardown used
the waitqueue as well.
--
Jens Axboe