Re: [PATCH RFC 1/2] fs/iomap/direct-io: pass NOWAIT to bio flags

[Christoph Hellwig]

On Mon, May 04, 2020 at 07:23:50PM +0300, Konstantin Khlebnikov wrote:
> On 04/05/2020 19.00, Christoph Hellwig wrote:
> > On Mon, May 04, 2020 at 06:54:53PM +0300, Konstantin Khlebnikov wrote:
> > > This is required to avoid waiting in lower layers.
> > > 
> > > Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
> > 
> > This looks sensible.  Did you run this through xfstests?
> > 
> 
> Nope. It seems xfstests has one trivial test for NOWAIT - generic/471
> It tests only write with/without extent, nothing about contention.
> 
> I've added nowait into fio and played with it a little.
> https://github.com/axboe/fio/pull/972
> 
> With these patches I see EAGAINs when queue is flooded.

Once the fio changes land, can you add a simple fio based test
to xfstests?