On Wed, Mar 8, 2023 at 9:54 AM Rob Clark wrote: > From: Rob Clark > > Add a new flag to let userspace provide a deadline as a hint for syncobj > and timeline waits. This gives a hint to the driver signaling the > backing fences about how soon userspace needs it to compete work, so it > can addjust GPU frequency accordingly. An immediate deadline can be > given to provide something equivalent to i915 "wait boost". > > v2: Use absolute u64 ns value for deadline hint, drop cap and driver > feature flag in favor of allowing count_handles==0 as a way for > userspace to probe kernel for support of new flag > v3: More verbose comments about UAPI > > Signed-off-by: Rob Clark > --- > drivers/gpu/drm/drm_syncobj.c | 64 ++++++++++++++++++++++++++++------- > include/uapi/drm/drm.h | 17 ++++++++++ > 2 files changed, 68 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c > index 0c2be8360525..a85e9464f07b 100644 > --- a/drivers/gpu/drm/drm_syncobj.c > +++ b/drivers/gpu/drm/drm_syncobj.c > @@ -126,6 +126,11 @@ > * synchronize between the two. > * This requirement is inherited from the Vulkan fence API. > * > + * If &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE is set, the ioctl will also > set > + * a fence deadline hint on the backing fences before waiting, to provide > the > + * fence signaler with an appropriate sense of urgency. The deadline is > + * specified as an absolute &CLOCK_MONOTONIC value in units of ns. > + * > * Similarly, &DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT takes an array of syncobj > * handles as well as an array of u64 points and does a host-side wait on > all > * of syncobj fences at the given points simultaneously. > @@ -973,7 +978,8 @@ static signed long > drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, > uint32_t count, > uint32_t flags, > signed long timeout, > - uint32_t *idx) > + uint32_t *idx, > + ktime_t *deadline) > { > struct syncobj_wait_entry *entries; > struct dma_fence *fence; > @@ -1053,6 +1059,15 @@ static signed long > drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, > drm_syncobj_fence_add_wait(syncobjs[i], > &entries[i]); > } > > + if (deadline) { > + for (i = 0; i < count; ++i) { > + fence = entries[i].fence; > + if (!fence) > + continue; > + dma_fence_set_deadline(fence, *deadline); > + } > + } > + > do { > set_current_state(TASK_INTERRUPTIBLE); > > @@ -1151,7 +1166,8 @@ static int drm_syncobj_array_wait(struct drm_device > *dev, > struct drm_file *file_private, > struct drm_syncobj_wait *wait, > struct drm_syncobj_timeline_wait > *timeline_wait, > - struct drm_syncobj **syncobjs, bool > timeline) > + struct drm_syncobj **syncobjs, bool > timeline, > + ktime_t *deadline) > { > signed long timeout = 0; > uint32_t first = ~0; > @@ -1162,7 +1178,8 @@ static int drm_syncobj_array_wait(struct drm_device > *dev, > NULL, > > wait->count_handles, > wait->flags, > - timeout, &first); > + timeout, &first, > + deadline); > if (timeout < 0) > return timeout; > wait->first_signaled = first; > @@ -1172,7 +1189,8 @@ static int drm_syncobj_array_wait(struct drm_device > *dev, > > u64_to_user_ptr(timeline_wait->points), > > timeline_wait->count_handles, > > timeline_wait->flags, > - timeout, &first); > + timeout, &first, > + deadline); > if (timeout < 0) > return timeout; > timeline_wait->first_signaled = first; > @@ -1243,17 +1261,22 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, > void *data, > { > struct drm_syncobj_wait *args = data; > struct drm_syncobj **syncobjs; > + unsigned possible_flags; > + ktime_t t, *tp = NULL; > int ret = 0; > > if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ)) > return -EOPNOTSUPP; > > - if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL | > - DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT)) > + possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL | > + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT | > + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE; > + > + if (args->flags & ~possible_flags) > return -EINVAL; > > if (args->count_handles == 0) > - return -EINVAL; > + return 0; > Did you intend this change? If so, why? What does waiting with no handles gain us? I mean, it's probably fine but it seems unrelated to this change. ret = drm_syncobj_array_find(file_private, > u64_to_user_ptr(args->handles), > @@ -1262,8 +1285,13 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, void > *data, > if (ret < 0) > return ret; > > + if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) { > + t = ns_to_ktime(args->deadline_ns); > + tp = &t; > + } > + > ret = drm_syncobj_array_wait(dev, file_private, > - args, NULL, syncobjs, false); > + args, NULL, syncobjs, false, tp); > > drm_syncobj_array_free(syncobjs, args->count_handles); > > @@ -1276,18 +1304,23 @@ drm_syncobj_timeline_wait_ioctl(struct drm_device > *dev, void *data, > { > struct drm_syncobj_timeline_wait *args = data; > struct drm_syncobj **syncobjs; > + unsigned possible_flags; > + ktime_t t, *tp = NULL; > int ret = 0; > > if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE)) > return -EOPNOTSUPP; > > - if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL | > - DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT | > - DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) > + possible_flags = DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL | > + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT | > + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE | > + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE; > + > + if (args->flags & ~possible_flags) > return -EINVAL; > > if (args->count_handles == 0) > - return -EINVAL; > + return -0; > Did you intend this change? -0 is a pretty weird integer. > ret = drm_syncobj_array_find(file_private, > u64_to_user_ptr(args->handles), > @@ -1296,8 +1329,13 @@ drm_syncobj_timeline_wait_ioctl(struct drm_device > *dev, void *data, > if (ret < 0) > return ret; > > + if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE) { > + t = ns_to_ktime(args->deadline_ns); > + tp = &t; > + } > + > ret = drm_syncobj_array_wait(dev, file_private, > - NULL, args, syncobjs, true); > + NULL, args, syncobjs, true, tp); > > drm_syncobj_array_free(syncobjs, args->count_handles); > > diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h > index 642808520d92..bff0509ac8b6 100644 > --- a/include/uapi/drm/drm.h > +++ b/include/uapi/drm/drm.h > @@ -887,6 +887,7 @@ struct drm_syncobj_transfer { > #define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0) > #define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1) > #define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE (1 << 2) /* wait for time > point to become available */ > +#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE (1 << 3) /* set fence > deadline based to deadline_ns */ > struct drm_syncobj_wait { > __u64 handles; > /* absolute timeout */ > @@ -895,6 +896,14 @@ struct drm_syncobj_wait { > __u32 flags; > __u32 first_signaled; /* only valid when not waiting all */ > __u32 pad; > + /** > + * @deadline_ns - fence deadline hint > + * > + * Deadline hint, in absolute CLOCK_MONOTONIC, to set on backing > + * fence(s) if the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE flag is > + * set. > + */ > + __u64 deadline_ns; > }; > > struct drm_syncobj_timeline_wait { > @@ -907,6 +916,14 @@ struct drm_syncobj_timeline_wait { > __u32 flags; > __u32 first_signaled; /* only valid when not waiting all */ > __u32 pad; > + /** > + * @deadline_ns - fence deadline hint > + * > + * Deadline hint, in absolute CLOCK_MONOTONIC, to set on backing > + * fence(s) if the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE flag is > + * set. > + */ > + __u64 deadline_ns; > }; > > > -- > 2.39.2 > >