Re: RAID1 might_sleep() warning on 3.19-rc7

Peter Zijlstra
2015-02-18T13:47:37Z

On Wed, Feb 18, 2015 at 12:09:36PM +1100, NeilBrown wrote:
> On Fri, 13 Feb 2015 15:48:03 +0100 Peter Zijlstra <peterz@infradead.org>
> wrote:
>
> > On Fri, Feb 13, 2015 at 11:27:46AM +0100, Peter Zijlstra wrote:
> >
> > > > I've moved blk_flush_plug to the beginning of the function.
> > >
> > > > I wondered if it really make sense to call blk_flush_plug with nr_iowait
> > > > elevated and delayacct_blkio active. blk_flush_plug() could call schedule()
> > > > for non-"io" reasons and maybe that could upset stuff???
> > >
> > > Yeah, good question that. Lemme ponder that a bit.
> >
> > Yes, I thikn your version makes most sense as, you say, even regular
> > schedule() call nested in my version would go towards blk delayacct --
> > and I doubt that was the intent; even though the current kernel works
> > that way.
> >
> > I'll move the now rudimentary io_schedule() into sched.h as an inline.
>
> Thanks.
>
> Are you OK with this going to -stable for 3.19?

OK, lets do that.