Re: [PATCH v2] io_uring: don't submit sqes when ctx->refs is dying

[Jens Axboe <axboe@xxxxxxxxx>]

On 5/20/20 1:35 AM, Xiaoguang Wang wrote:
> When IORING_SETUP_SQPOLL is enabled, io_ring_ctx_wait_and_kill() will wait
> for sq thread to idle by busy loop:
>     while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait))
>         cond_resched();
> Above codes are not friendly, indeed I think this busy loop will introduce a
> cpu burst in current cpu, though it maybe short.
> 
> In this patch, if ctx->refs is dying, we forbids sq_thread from submitting
> sqes anymore, just discard leftover sqes.

Applied for 5.8, thanks.

-- 
Jens Axboe