[PATCH 2/2] drm/xe/oa/uapi: Allow preemption to be disabled on the stream exec queue
Matthew Brost
matthew.brost at intel.com
Wed Jun 26 22:19:37 UTC 2024
On Wed, Jun 26, 2024 at 11:18:17AM -0700, Ashutosh Dixit wrote:
> Mesa VK_KHR_performance_query use case requires preemption and timeslicing
> to be disabled for the stream exec queue. Implement this functionality
> here.
>
> v2: Minor change to debug print to print both ret values (Umesh)
>
> Acked-by: José Roberto de Souza <jose.souza at intel.com>
Acked-by: Matthew Brost <matthew.brost at intel.com>
> Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
> ---
> drivers/gpu/drm/xe/xe_oa.c | 70 +++++++++++++++++++++++++++++++-
> drivers/gpu/drm/xe/xe_oa_types.h | 3 ++
> include/uapi/drm/xe_drm.h | 6 +++
> 3 files changed, 78 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
> index a68659fd5386..6cc3f0217341 100644
> --- a/drivers/gpu/drm/xe/xe_oa.c
> +++ b/drivers/gpu/drm/xe/xe_oa.c
> @@ -80,6 +80,7 @@ struct xe_oa_open_param {
> int engine_instance;
> struct xe_exec_queue *exec_q;
> struct xe_hw_engine *hwe;
> + bool no_preempt;
> };
>
> struct xe_oa_config_bo {
> @@ -1013,11 +1014,55 @@ static void xe_oa_stream_disable(struct xe_oa_stream *stream)
> hrtimer_cancel(&stream->poll_check_timer);
> }
>
> +static int xe_oa_enable_preempt_timeslice(struct xe_oa_stream *stream)
> +{
> + struct xe_exec_queue *q = stream->exec_q;
> + int ret1, ret2;
> +
> + /* Best effort recovery: try to revert both to original, irrespective of error */
> + ret1 = q->ops->set_timeslice(q, stream->hwe->eclass->sched_props.timeslice_us);
> + ret2 = q->ops->set_preempt_timeout(q, stream->hwe->eclass->sched_props.preempt_timeout_us);
> + if (ret1 || ret2)
> + goto err;
> + return 0;
> +err:
> + drm_dbg(&stream->oa->xe->drm, "%s failed ret1 %d ret2 %d\n", __func__, ret1, ret2);
> + return ret1 ?: ret2;
> +}
> +
> +static int xe_oa_disable_preempt_timeslice(struct xe_oa_stream *stream)
> +{
> + struct xe_exec_queue *q = stream->exec_q;
> + int ret;
> +
> + /* Setting values to 0 will disable timeslice and preempt_timeout */
> + ret = q->ops->set_timeslice(q, 0);
> + if (ret)
> + goto err;
> +
> + ret = q->ops->set_preempt_timeout(q, 0);
> + if (ret)
> + goto err;
> +
> + return 0;
> +err:
> + xe_oa_enable_preempt_timeslice(stream);
> + drm_dbg(&stream->oa->xe->drm, "%s failed %d\n", __func__, ret);
> + return ret;
> +}
> +
> static int xe_oa_enable_locked(struct xe_oa_stream *stream)
> {
> if (stream->enabled)
> return 0;
>
> + if (stream->no_preempt) {
> + int ret = xe_oa_disable_preempt_timeslice(stream);
> +
> + if (ret)
> + return ret;
> + }
> +
> xe_oa_stream_enable(stream);
>
> stream->enabled = true;
> @@ -1026,13 +1071,18 @@ static int xe_oa_enable_locked(struct xe_oa_stream *stream)
>
> static int xe_oa_disable_locked(struct xe_oa_stream *stream)
> {
> + int ret = 0;
> +
> if (!stream->enabled)
> return 0;
>
> xe_oa_stream_disable(stream);
>
> + if (stream->no_preempt)
> + ret = xe_oa_enable_preempt_timeslice(stream);
> +
> stream->enabled = false;
> - return 0;
> + return ret;
> }
>
> static long xe_oa_config_locked(struct xe_oa_stream *stream, u64 arg)
> @@ -1307,6 +1357,7 @@ static int xe_oa_stream_init(struct xe_oa_stream *stream,
> stream->sample = param->sample;
> stream->periodic = param->period_exponent > 0;
> stream->period_exponent = param->period_exponent;
> + stream->no_preempt = param->no_preempt;
>
> /*
> * For Xe2+, when overrun mode is enabled, there are no partial reports at the end
> @@ -1651,6 +1702,13 @@ static int xe_oa_set_prop_engine_instance(struct xe_oa *oa, u64 value,
> return 0;
> }
>
> +static int xe_oa_set_no_preempt(struct xe_oa *oa, u64 value,
> + struct xe_oa_open_param *param)
> +{
> + param->no_preempt = value;
> + return 0;
> +}
> +
> typedef int (*xe_oa_set_property_fn)(struct xe_oa *oa, u64 value,
> struct xe_oa_open_param *param);
> static const xe_oa_set_property_fn xe_oa_set_property_funcs[] = {
> @@ -1662,6 +1720,7 @@ static const xe_oa_set_property_fn xe_oa_set_property_funcs[] = {
> [DRM_XE_OA_PROPERTY_OA_DISABLED] = xe_oa_set_prop_disabled,
> [DRM_XE_OA_PROPERTY_EXEC_QUEUE_ID] = xe_oa_set_prop_exec_queue_id,
> [DRM_XE_OA_PROPERTY_OA_ENGINE_INSTANCE] = xe_oa_set_prop_engine_instance,
> + [DRM_XE_OA_PROPERTY_NO_PREEMPT] = xe_oa_set_no_preempt,
> };
>
> static int xe_oa_user_ext_set_property(struct xe_oa *oa, u64 extension,
> @@ -1766,6 +1825,15 @@ int xe_oa_stream_open_ioctl(struct drm_device *dev, u64 data, struct drm_file *f
> if (param.exec_q && !param.sample)
> privileged_op = false;
>
> + if (param.no_preempt) {
> + if (!param.exec_q) {
> + drm_dbg(&oa->xe->drm, "Preemption disable without exec_q!\n");
> + ret = -EINVAL;
> + goto err_exec_q;
> + }
> + privileged_op = true;
> + }
> +
> if (privileged_op && xe_perf_stream_paranoid && !perfmon_capable()) {
> drm_dbg(&oa->xe->drm, "Insufficient privileges to open xe perf stream\n");
> ret = -EACCES;
> diff --git a/drivers/gpu/drm/xe/xe_oa_types.h b/drivers/gpu/drm/xe/xe_oa_types.h
> index 706d45577dae..540c3ec53a6d 100644
> --- a/drivers/gpu/drm/xe/xe_oa_types.h
> +++ b/drivers/gpu/drm/xe/xe_oa_types.h
> @@ -235,5 +235,8 @@ struct xe_oa_stream {
>
> /** @oa_status: temporary storage for oa_status register value */
> u32 oa_status;
> +
> + /** @no_preempt: Whether preemption and timeslicing is disabled for stream exec_q */
> + u32 no_preempt;
> };
> #endif
> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> index b410553faa9b..12eaa8532b5c 100644
> --- a/include/uapi/drm/xe_drm.h
> +++ b/include/uapi/drm/xe_drm.h
> @@ -1611,6 +1611,12 @@ enum drm_xe_oa_property_id {
> * pass along with @DRM_XE_OA_PROPERTY_EXEC_QUEUE_ID or will default to 0.
> */
> DRM_XE_OA_PROPERTY_OA_ENGINE_INSTANCE,
> +
> + /**
> + * @DRM_XE_OA_PROPERTY_NO_PREEMPT: Allow preemption and timeslicing
> + * to be disabled for the stream exec queue.
> + */
> + DRM_XE_OA_PROPERTY_NO_PREEMPT,
> };
>
> /**
> --
> 2.41.0
>
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