| Message ID | 158860769311.32485.8003552176738816448.stgit@buzz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC,1/2] fs/iomap/direct-io: pass NOWAIT to bio flags | expand |
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@yandex-team.ru> This looks sensible. Did you run this through xfstests?
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@yandex-team.ru> > > 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.
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@yandex-team.ru> > > > > 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?
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@yandex-team.ru> Looks good, Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 20dde5aadcdd..9b53fa7651e3 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -63,6 +63,8 @@ static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap, { atomic_inc(&dio->ref); + if (dio->iocb->ki_flags & IOCB_NOWAIT) + bio->bi_opf |= REQ_NOWAIT; if (dio->iocb->ki_flags & IOCB_HIPRI) bio_set_polled(bio, dio->iocb);
This is required to avoid waiting in lower layers. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> --- fs/iomap/direct-io.c | 2 ++ 1 file changed, 2 insertions(+)