Re: [PATCH] io_uring: trigger worker exit when ring is exiting

[Jens Axboe <axboe@kernel.dk>]

On 9/2/21 12:04 PM, Pavel Begunkov wrote:
> On 9/2/21 6:56 PM, Jens Axboe wrote:
>> If a task exits normally, then the teardown of async workers happens
>> quickly. But if it simply closes the ring fd, then the async teardown
>> ends up waiting for workers to timeout if they are sleeping, which can
>> then take up to 5 seconds (by default). This isn't a big issue as this
>> happens off the workqueue path, but let's be nicer and ensure that we
>> exit as quick as possible.
> 
> ring = io_uring_init();
> ...
> io_uring_close(&ring); // triggers io_ring_ctx_wait_and_kill()
> rint2 = io_uring_init();
> ...
> 
> It looks IO_WQ_BIT_EXIT there will be troublesome.

I wonder if we can get by with just a wakeup. Let me test...

-- 
Jens Axboe