Re: [PATCH 0/6] Allow signals for IO threads

From: Jens Axboe
Date: Fri Mar 26 2021 - 10:39:27 EST


On 3/26/21 7:59 AM, Jens Axboe wrote:
> On 3/26/21 7:54 AM, Jens Axboe wrote:
>>> The KILL after STOP deadlock still exists.
>>
>> In which tree? Sounds like you're still on the old one with that
>> incremental you sent, which wasn't complete.
>>
>>> Does io_wq_manager() exits without cleaning up on SIGKILL?
>>
>> No, it should kill up in all cases. I'll try your stop + kill, I just
>> tested both of them separately and didn't observe anything. I also ran
>> your io_uring-cp example (and found a bug in the example, fixed and
>> pushed), fwiw.
>
> I can reproduce this one! I'll take a closer look.

OK, that one is actually pretty straight forward - we rely on cleaning
up on exit, but for fatal cases, get_signal() will call do_exit() for us
and never return. So we might need a special case in there to deal with
that, or some other way of ensuring that fatal signal gets processed
correctly for IO threads.

--
Jens Axboe