| Message ID | 20171115171057.17340-4-gustavo@padovan.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thursday, November 16, 2017 2:10:49 AM JST, Gustavo Padovan wrote: > From: Gustavo Padovan <gustavo.padovan@collabora.com> > > We use ordered_in_driver property to optimize for the case where > the driver can deliver the buffers in an ordered fashion. When it > is ordered we can use the same fence context for all fences, but > when it is not we need to a new context for each out-fence. "we need to a new context" looks like it is missing a word.
2017-11-17 Alexandre Courbot <acourbot@chromium.org>: > On Thursday, November 16, 2017 2:10:49 AM JST, Gustavo Padovan wrote: > > From: Gustavo Padovan <gustavo.padovan@collabora.com> > > > > We use ordered_in_driver property to optimize for the case where > > the driver can deliver the buffers in an ordered fashion. When it > > is ordered we can use the same fence context for all fences, but > > when it is not we need to a new context for each out-fence. > > "we need to a new context" looks like it is missing a word. oh "we need to create a new context" Thanks for reviewing the patches! Gustavo
Em Wed, 15 Nov 2017 15:10:49 -0200 Gustavo Padovan <gustavo@padovan.org> escreveu: > From: Gustavo Padovan <gustavo.padovan@collabora.com> > > We use ordered_in_driver property to optimize for the case where > the driver can deliver the buffers in an ordered fashion. When it > is ordered we can use the same fence context for all fences, but > when it is not we need to a new context for each out-fence. > > So the ordered_in_driver flag will help us with identifying the queues > that can be optimized and use the same fence context. > > v4: make the property a vector for optimization and not a mandatory thing > that drivers need to set if they want to use explicit synchronization. > > v3: improve doc (Hans Verkuil) > > v2: rename property to 'ordered_in_driver' to avoid confusion > > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com> > --- > include/media/videobuf2-core.h | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index ef9b64398c8c..38b9c8dd42c6 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -440,6 +440,12 @@ struct vb2_buf_ops { > * @fileio_read_once: report EOF after reading the first buffer > * @fileio_write_immediately: queue buffer after each write() call > * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver > + * @ordered_in_driver: if the driver can guarantee that the queue will be > + * ordered or not, i.e., the buffers are dequeued from the driver > + * in the same order they are queued to the driver. The default > + * is not ordered unless the driver sets this flag. Setting it > + * when ordering can be guaranted helps to optimize explicit > + * fences. > * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF > * has not been called. This is a vb1 idiom that has been adopted > * also by vb2. > @@ -510,6 +516,7 @@ struct vb2_queue { > unsigned fileio_read_once:1; > unsigned fileio_write_immediately:1; > unsigned allow_zero_bytesused:1; > + unsigned ordered_in_driver:1; As this may depend on the format, it is probably a good idea to set this flag either via a function argument or by a function that would be meant to update it, as video format changes. > unsigned quirk_poll_must_check_waiting_for_buffers:1; > > struct mutex *lock;
Hi Mauro, 2017-11-17 Mauro Carvalho Chehab <mchehab@osg.samsung.com>: > Em Wed, 15 Nov 2017 15:10:49 -0200 > Gustavo Padovan <gustavo@padovan.org> escreveu: > > > From: Gustavo Padovan <gustavo.padovan@collabora.com> > > > > We use ordered_in_driver property to optimize for the case where > > the driver can deliver the buffers in an ordered fashion. When it > > is ordered we can use the same fence context for all fences, but > > when it is not we need to a new context for each out-fence. > > > > So the ordered_in_driver flag will help us with identifying the queues > > that can be optimized and use the same fence context. > > > > v4: make the property a vector for optimization and not a mandatory thing > > that drivers need to set if they want to use explicit synchronization. > > > > v3: improve doc (Hans Verkuil) > > > > v2: rename property to 'ordered_in_driver' to avoid confusion > > > > Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com> > > --- > > include/media/videobuf2-core.h | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > > index ef9b64398c8c..38b9c8dd42c6 100644 > > --- a/include/media/videobuf2-core.h > > +++ b/include/media/videobuf2-core.h > > @@ -440,6 +440,12 @@ struct vb2_buf_ops { > > * @fileio_read_once: report EOF after reading the first buffer > > * @fileio_write_immediately: queue buffer after each write() call > > * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver > > + * @ordered_in_driver: if the driver can guarantee that the queue will be > > + * ordered or not, i.e., the buffers are dequeued from the driver > > + * in the same order they are queued to the driver. The default > > + * is not ordered unless the driver sets this flag. Setting it > > + * when ordering can be guaranted helps to optimize explicit > > + * fences. > > * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF > > * has not been called. This is a vb1 idiom that has been adopted > > * also by vb2. > > @@ -510,6 +516,7 @@ struct vb2_queue { > > unsigned fileio_read_once:1; > > unsigned fileio_write_immediately:1; > > unsigned allow_zero_bytesused:1; > > + unsigned ordered_in_driver:1; > > As this may depend on the format, it is probably a good idea to set > this flag either via a function argument or by a function that > would be meant to update it, as video format changes. Right, and maybe I can find a way to store this in only one place, istead of what I did here (having to set explicitely both the ordered_in_driver and the flag separatedly) Gustavo
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index ef9b64398c8c..38b9c8dd42c6 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -440,6 +440,12 @@ struct vb2_buf_ops { * @fileio_read_once: report EOF after reading the first buffer * @fileio_write_immediately: queue buffer after each write() call * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver + * @ordered_in_driver: if the driver can guarantee that the queue will be + * ordered or not, i.e., the buffers are dequeued from the driver + * in the same order they are queued to the driver. The default + * is not ordered unless the driver sets this flag. Setting it + * when ordering can be guaranted helps to optimize explicit + * fences. * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF * has not been called. This is a vb1 idiom that has been adopted * also by vb2. @@ -510,6 +516,7 @@ struct vb2_queue { unsigned fileio_read_once:1; unsigned fileio_write_immediately:1; unsigned allow_zero_bytesused:1; + unsigned ordered_in_driver:1; unsigned quirk_poll_must_check_waiting_for_buffers:1; struct mutex *lock;