On Sat, 18 Feb 2023 13:15:52 -0800 Rob Clark <robdcl...@gmail.com> wrote:
> From: Rob Clark <robdcl...@chromium.org>
>
> 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".
>
> Signed-off-by: Rob Clark <robdcl...@chromium.org>
> ---
>
> I'm a bit on the fence about the addition of the DRM_CAP, but it seems
> useful to give userspace a way to probe whether the kernel and driver
> supports the new wait flag, especially since we have vk-common code
> dealing with syncobjs. But open to suggestions.
>
> drivers/gpu/drm/drm_ioctl.c | 3 ++
> drivers/gpu/drm/drm_syncobj.c | 59 ++++++++++++++++++++++++++++-------
> include/drm/drm_drv.h | 6 ++++
> include/uapi/drm/drm.h | 16 ++++++++--
> 4 files changed, 71 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index 7c9d66ee917d..1c5c942cf0f9 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -254,6 +254,9 @@ static int drm_getcap(struct drm_device *dev, void *data,
> struct drm_file *file_
> case DRM_CAP_SYNCOBJ_TIMELINE:
> req->value = drm_core_check_feature(dev,
> DRIVER_SYNCOBJ_TIMELINE);
> return 0;
> + case DRM_CAP_SYNCOBJ_DEADLINE:
> + req->value = drm_core_check_feature(dev,
> DRIVER_SYNCOBJ_TIMELINE);
Hi,
is that a typo for DRIVER_SYNCOBJ_DEADLINE?
> + return 0;
> }
>
> /* Other caps only work with KMS drivers */
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 0c2be8360525..61cf97972a60 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -973,7 +973,8 @@ 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 +1054,15 @@ 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 +1161,8 @@ 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 +1173,8 @@ 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 +1184,8 @@ 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;
> @@ -1243,13 +1256,20 @@ 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;
> +
> + if (drm_core_check_feature(dev, DRIVER_SYNCOBJ_DEADLINE))
> + possible_flags |= DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
> +
> + if (args->flags & ~possible_flags)
> return -EINVAL;
>
> if (args->count_handles == 0)
> @@ -1262,8 +1282,13 @@ 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 = ktime_set(args->deadline_sec, args->deadline_nsec);
> + 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);
>
> @@ -1276,14 +1301,21 @@ 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;
> +
> + if (drm_core_check_feature(dev, DRIVER_SYNCOBJ_DEADLINE))
> + possible_flags |= DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE;
> +
> + if (args->flags & ~possible_flags)
> return -EINVAL;
>
> if (args->count_handles == 0)
> @@ -1296,8 +1328,13 @@ 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 = ktime_set(args->deadline_sec, args->deadline_nsec);
> + 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/drm/drm_drv.h b/include/drm/drm_drv.h
> index 1d76d0686b03..9aa24f097e22 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -104,6 +104,12 @@ enum drm_driver_feature {
> * acceleration should be handled by two drivers that are connected
> using auxiliary bus.
> */
> DRIVER_COMPUTE_ACCEL = BIT(7),
> + /**
> + * @DRIVER_SYNCOBJ_DEADLINE:
> + *
> + * Driver supports &dma_fence_ops.set_deadline
> + */
> + DRIVER_SYNCOBJ_DEADLINE = BIT(8),
>
> /* IMPORTANT: Below are all the legacy flags, add new ones above. */
>
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 642808520d92..c6b85bb13810 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -767,6 +767,13 @@ struct drm_gem_open {
> * Documentation/gpu/drm-mm.rst, section "DRM Sync Objects".
> */
> #define DRM_CAP_SYNCOBJ_TIMELINE 0x14
> +/**
> + * DRM_CAP_SYNCOBJ_DEADLINE
> + *
> + * If set to 1, the driver supports DRM_SYNCOBJ_WAIT_FLAGS_WAIT_DEADLINE flag
> + * on the SYNCOBJ_TIMELINE_WAIT/SYNCOBJ_WAIT ioctls.
> + */
> +#define DRM_CAP_SYNCOBJ_DEADLINE 0x15
>
> /* DRM_IOCTL_GET_CAP ioctl argument type */
> struct drm_get_cap {
> @@ -887,6 +894,7 @@ 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_nsec/sec */
Where was the UAPI documentation explaining what a fence deadline is
and what it does, again?
> struct drm_syncobj_wait {
> __u64 handles;
> /* absolute timeout */
> @@ -894,7 +902,9 @@ struct drm_syncobj_wait {
> __u32 count_handles;
> __u32 flags;
> __u32 first_signaled; /* only valid when not waiting all */
> - __u32 pad;
> + /* Deadline to set on backing fence(s) in CLOCK_MONOTONIC: */
> + __u32 deadline_nsec;
> + __u64 deadline_sec;
> };
>
> struct drm_syncobj_timeline_wait {
> @@ -906,7 +916,9 @@ struct drm_syncobj_timeline_wait {
> __u32 count_handles;
> __u32 flags;
> __u32 first_signaled; /* only valid when not waiting all */
> - __u32 pad;
> + /* Deadline to set on backing fence(s) in CLOCK_MONOTONIC: */
> + __u32 deadline_nsec;
> + __u64 deadline_sec;
> };
It seems inconsistent that these sec,nsec are here unsigned, when in
other places they are signed. There is also the question if these need
to meet clock_settime() requirements of valid values.
Thanks,
pq
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