Re: [PATCH 2/2] kernel: rerun task_work while freezing in get_signal()

[Pavel Begunkov]

On 7/9/24 20:38, Oleg Nesterov wrote:
> On 07/09, Pavel Begunkov wrote:
> > On 7/9/24 20:07, Oleg Nesterov wrote:
> > > Hi Tejun,
> > >
> > > Thanks for looking at this, can you review this V2 patch from Pavel?
>
> Just in case, I obviously meant our next (V2) patch
>
> [PATCH v2 2/2] kernel: rerun task_work while freezing in get_signal()
> https://lore.kernel.org/all/149ff5a762997c723880751e8a4019907a0b6457.1720534425.git.asml.silence@xxxxxxxxx/
>
> > > Well, I don't really understand what can snapshot/restore actually mean...
> >
> > CRIU, I assume. I'll try it ...
>
> Than I think we can forget about task_works and this patch. CRIU dumps
> the tasks in TASK_TRACED state.

And would be hard to test, io_uring (the main source of task_work)
is not supported

(00.466022) Error (criu/proc_parse.c:477): Unknown shit 600 (anon_inode:[io_uring])
...
(00.467642) Unfreezing tasks into 1
(00.467656)     Unseizing 15488 into 1
(00.468149) Error (criu/cr-dump.c:2111): Dumping FAILED.


> > ... but I'm inclined to think the patch makes sense regardless,
> > we're replacing an infinite loop with wait-wake-execute-wait.
>
> Agreed.

--
Pavel Begunkov