Re: [GIT PULL] aio: fix sleeping while TASK_INTERRUPTIBLE

[Jens Axboe]

On 02/03/2015 04:55 AM, Peter Zijlstra wrote:
> On Tue, Feb 03, 2015 at 12:33:48PM +0100, Peter Zijlstra wrote:
> > > block/bsg.c-    prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
> > > block/bsg.c-    spin_unlock_irq(&bd->lock);
> > > block/bsg.c:    io_schedule();
> > > block/bsg.c-    finish_wait(&bd->wq_done, &wait);
> > >
> > > Which is double buggy because:
> > >   1) it doesn't loop
> > >   2) it sets TASK_UNINTERRUPTIBLE _after_ testing for the sleep event.
> >
> > OK, actually had a look at this one; it might be ok.
> >
> > The spinlock might fully serialize the state so no fails, and the entire
> > function is called in a loop. Still seriously obtuse code.
>
> Jens, would something like the below work for you?

Yes, from a cursory look, that seems fine to me. Though I will hold the 
fact that you label my code as 'seriously obtuse' against you. Some day.

I can pull this in for testing for 3.20. Mind sending a properly 
formatted patch (signed off, commit message, all that stuff)?

--
Jens Axboe

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