On Mon, 27 Feb 2023 11:35:11 -0800 Rob Clark <robdclark@xxxxxxxxx> wrote: > From: Rob Clark <robdclark@xxxxxxxxxxxx> > > The initial purpose is for igt tests, but this would also be useful for > compositors that wait until close to vblank deadline to make decisions > about which frame to show. > > The igt tests can be found at: > > https://gitlab.freedesktop.org/robclark/igt-gpu-tools/-/commits/fence-deadline > > v2: Clarify the timebase, add link to igt tests > v3: Use u64 value in ns to express deadline. > v4: More doc > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> > --- > drivers/dma-buf/dma-fence.c | 3 ++- > drivers/dma-buf/sync_file.c | 19 +++++++++++++++++++ > include/uapi/linux/sync_file.h | 22 ++++++++++++++++++++++ > 3 files changed, 43 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > index e103e821d993..7761ceeae620 100644 > --- a/drivers/dma-buf/dma-fence.c > +++ b/drivers/dma-buf/dma-fence.c > @@ -933,7 +933,8 @@ EXPORT_SYMBOL(dma_fence_wait_any_timeout); > * the GPU's devfreq to reduce frequency, when in fact the opposite is what is > * needed. > * > - * To this end, deadline hint(s) can be set on a &dma_fence via &dma_fence_set_deadline. > + * To this end, deadline hint(s) can be set on a &dma_fence via &dma_fence_set_deadline > + * (or indirectly via userspace facing ioctls like &SYNC_IOC_SET_DEADLINE). > * The deadline hint provides a way for the waiting driver, or userspace, to > * convey an appropriate sense of urgency to the signaling driver. Hi, when the kernel HTML doc is generated, I assume the above becomes a link to "DOC: SYNC_IOC_SET_DEADLINE - set a deadline on a fence", right? > * > diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c > index af57799c86ce..418021cfb87c 100644 > --- a/drivers/dma-buf/sync_file.c > +++ b/drivers/dma-buf/sync_file.c > @@ -350,6 +350,22 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, > return ret; > } > > +static int sync_file_ioctl_set_deadline(struct sync_file *sync_file, > + unsigned long arg) > +{ > + struct sync_set_deadline ts; > + > + if (copy_from_user(&ts, (void __user *)arg, sizeof(ts))) > + return -EFAULT; > + > + if (ts.pad) > + return -EINVAL; > + > + dma_fence_set_deadline(sync_file->fence, ns_to_ktime(ts.deadline_ns)); > + > + return 0; > +} > + > static long sync_file_ioctl(struct file *file, unsigned int cmd, > unsigned long arg) > { > @@ -362,6 +378,9 @@ static long sync_file_ioctl(struct file *file, unsigned int cmd, > case SYNC_IOC_FILE_INFO: > return sync_file_ioctl_fence_info(sync_file, arg); > > + case SYNC_IOC_SET_DEADLINE: > + return sync_file_ioctl_set_deadline(sync_file, arg); > + > default: > return -ENOTTY; > } > diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h > index ee2dcfb3d660..49325cf6749b 100644 > --- a/include/uapi/linux/sync_file.h > +++ b/include/uapi/linux/sync_file.h > @@ -67,6 +67,21 @@ struct sync_file_info { > __u64 sync_fence_info; > }; > > +/** > + * struct sync_set_deadline - set a deadline hint on a fence > + * @deadline_ns: absolute time of the deadline Is it legal to pass zero as deadline_ns? > + * @pad: must be zero > + * > + * The timebase for the deadline is CLOCK_MONOTONIC (same as vblank) Does something here provide doc links to "DOC: SYNC_IOC_SET_DEADLINE - set a deadline on a fence" and to the "DOC: deadline hints"? > + */ > +struct sync_set_deadline { > + __u64 deadline_ns; > + /* Not strictly needed for alignment but gives some possibility > + * for future extension: > + */ > + __u64 pad; > +}; > + > #define SYNC_IOC_MAGIC '>' > > /** > @@ -95,4 +110,11 @@ struct sync_file_info { > */ > #define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info) > > +/** > + * DOC: SYNC_IOC_SET_DEADLINE - set a deadline on a fence > + * > + * Allows userspace to set a deadline on a fence, see dma_fence_set_deadline() Does something here provide doc links to struct sync_set_deadline and to the "DOC: deadline hints"? > + */ > +#define SYNC_IOC_SET_DEADLINE _IOW(SYNC_IOC_MAGIC, 5, struct sync_set_deadline) > + > #endif /* _UAPI_LINUX_SYNC_H */ With all those links added: Acked-by: Pekka Paalanen <pekka.paalanen@xxxxxxxxxxxxx> Thanks, pq
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