Re: (subset) [PATCH 00/11] remove aux CQE caches

[Jens Axboe <axboe@kernel.dk>]

On 3/17/24 7:34 PM, Jens Axboe wrote:
>>> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
>>> index a2cb8da3cc33..f1d3c5e065e9 100644
>>> --- a/io_uring/io_uring.c
>>> +++ b/io_uring/io_uring.c
>>> @@ -3242,6 +3242,8 @@ static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
>>>  	ret |= io_kill_timeouts(ctx, task, cancel_all);
>>>  	if (task)
>>>  		ret |= io_run_task_work() > 0;
>>> +	else if (ret)
>>> +		flush_delayed_work(&ctx->fallback_work);
>>>  	return ret;
>>>  }
>>
>> Still can trigger the warning with above patch:
>>
>> [  446.275975] ------------[ cut here ]------------
>> [  446.276340] WARNING: CPU: 8 PID: 731 at kernel/fork.c:969 __put_task_struct+0x10c/0x180
> 
> And this is running that test case you referenced? I'll take a look, as
> it seems related to the poll kill rather than the other patchset.

I can reproduce with that test too, and it triggers with v2 of the
patchset on top of io_uring-6.9, with and without that poll patch. Which
makes sense, as I doubt you're doing any poll or timeouts in there.

Pavel, passing that one to you then :)

-- 
Jens Axboe