| Message ID | 20230919050155.2647172-5-matthew.brost@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DRM scheduler changes for Xe | expand |
Hi, On 2023-09-19 01:01, Matthew Brost wrote: > DRM_SCHED_POLICY_SINGLE_ENTITY creates a 1 to 1 relationship between > scheduler and entity. No priorities or run queue used in this mode. > Intended for devices with firmware schedulers. > > v2: > - Drop sched / rq union (Luben) > v3: > - Don't pick entity if stopped in drm_sched_select_entity (Danilo) > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > --- > drivers/gpu/drm/scheduler/sched_entity.c | 69 ++++++++++++++++++------ > drivers/gpu/drm/scheduler/sched_fence.c | 2 +- > drivers/gpu/drm/scheduler/sched_main.c | 64 +++++++++++++++++++--- > include/drm/gpu_scheduler.h | 8 +++ > 4 files changed, 120 insertions(+), 23 deletions(-) > > diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c > index cf42e2265d64..437c50867c99 100644 > --- a/drivers/gpu/drm/scheduler/sched_entity.c > +++ b/drivers/gpu/drm/scheduler/sched_entity.c > @@ -83,6 +83,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, > memset(entity, 0, sizeof(struct drm_sched_entity)); > INIT_LIST_HEAD(&entity->list); > entity->rq = NULL; > + entity->single_sched = NULL; > entity->guilty = guilty; > entity->num_sched_list = num_sched_list; > entity->priority = priority; > @@ -90,8 +91,17 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, > RCU_INIT_POINTER(entity->last_scheduled, NULL); > RB_CLEAR_NODE(&entity->rb_tree_node); > > - if(num_sched_list) > - entity->rq = &sched_list[0]->sched_rq[entity->priority]; > + if (num_sched_list) { > + if (sched_list[0]->sched_policy != > + DRM_SCHED_POLICY_SINGLE_ENTITY) { > + entity->rq = &sched_list[0]->sched_rq[entity->priority]; > + } else { > + if (num_sched_list != 1 || sched_list[0]->single_entity) > + return -EINVAL; > + sched_list[0]->single_entity = entity; > + entity->single_sched = sched_list[0]; > + } > + } So much (checking for) negativity...:-) Perhaps the simplified form below? if (num_sched_list) { if (sched_list[0]->sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY) { entity->rq = &sched_list[0]->sched_rq[entity->priority]; } else if (num_sched_list == 1 && !sched_list[0]->single_entity) { sched_list[0]->single_entity = entity; entity->single_sched = sched_list[0]; } else { return -EINVAL; } } > > init_completion(&entity->entity_idle); > > @@ -124,7 +134,8 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, > struct drm_gpu_scheduler **sched_list, > unsigned int num_sched_list) > { > - WARN_ON(!num_sched_list || !sched_list); > + WARN_ON(!num_sched_list || !sched_list || > + !!entity->single_sched); > > entity->sched_list = sched_list; > entity->num_sched_list = num_sched_list; > @@ -231,13 +242,15 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) > { > struct drm_sched_job *job; > struct dma_fence *prev; > + bool single_entity = !!entity->single_sched; > > - if (!entity->rq) > + if (!entity->rq && !single_entity) > return; > > spin_lock(&entity->rq_lock); > entity->stopped = true; > - drm_sched_rq_remove_entity(entity->rq, entity); > + if (!single_entity) > + drm_sched_rq_remove_entity(entity->rq, entity); > spin_unlock(&entity->rq_lock); > > /* Make sure this entity is not used by the scheduler at the moment */ > @@ -259,6 +272,20 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) > dma_fence_put(prev); > } > > +/** > + * drm_sched_entity_to_scheduler - Schedule entity to GPU scheduler Please use verbs. Please? Fix: /** * drm_sched_entity_to_scheduler - Map a schedule entity to a GPU scheduler > + * @entity: scheduler entity > + * > + * Returns GPU scheduler for the entity Fix: * Given an entity, return its GPU scheduler. > + */ > +struct drm_gpu_scheduler * > +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity) > +{ > + bool single_entity = !!entity->single_sched; > + > + return single_entity ? entity->single_sched : entity->rq->sched; > +} > + > /** > * drm_sched_entity_flush - Flush a context entity > * > @@ -276,11 +303,12 @@ long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout) > struct drm_gpu_scheduler *sched; > struct task_struct *last_user; > long ret = timeout; > + bool single_entity = !!entity->single_sched; > > - if (!entity->rq) > + if (!entity->rq && !single_entity) > return 0; > > - sched = entity->rq->sched; > + sched = drm_sched_entity_to_scheduler(entity); > /** > * The client will not queue more IBs during this fini, consume existing > * queued IBs or discard them on SIGKILL > @@ -373,7 +401,7 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, > container_of(cb, struct drm_sched_entity, cb); > > drm_sched_entity_clear_dep(f, cb); > - drm_sched_wakeup_if_can_queue(entity->rq->sched); > + drm_sched_wakeup_if_can_queue(drm_sched_entity_to_scheduler(entity)); > } > > /** > @@ -387,6 +415,8 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, > void drm_sched_entity_set_priority(struct drm_sched_entity *entity, > enum drm_sched_priority priority) > { > + WARN_ON(!!entity->single_sched); > + > spin_lock(&entity->rq_lock); > entity->priority = priority; > spin_unlock(&entity->rq_lock); > @@ -399,7 +429,7 @@ EXPORT_SYMBOL(drm_sched_entity_set_priority); > */ > static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) > { > - struct drm_gpu_scheduler *sched = entity->rq->sched; > + struct drm_gpu_scheduler *sched = drm_sched_entity_to_scheduler(entity); > struct dma_fence *fence = entity->dependency; > struct drm_sched_fence *s_fence; > > @@ -501,7 +531,8 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) > * Update the entity's location in the min heap according to > * the timestamp of the next job, if any. > */ > - if (entity->rq->sched->sched_policy == DRM_SCHED_POLICY_FIFO) { > + if (drm_sched_entity_to_scheduler(entity)->sched_policy == > + DRM_SCHED_POLICY_FIFO) { > struct drm_sched_job *next; > > next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); > @@ -524,6 +555,8 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) > struct drm_gpu_scheduler *sched; > struct drm_sched_rq *rq; > > + WARN_ON(!!entity->single_sched); > + > /* single possible engine and already selected */ > if (!entity->sched_list) > return; > @@ -573,12 +606,13 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) > void drm_sched_entity_push_job(struct drm_sched_job *sched_job) > { > struct drm_sched_entity *entity = sched_job->entity; > - bool first, fifo = entity->rq->sched->sched_policy == > - DRM_SCHED_POLICY_FIFO; > + bool single_entity = !!entity->single_sched; > + bool first; > ktime_t submit_ts; > > trace_drm_sched_job(sched_job, entity); > - atomic_inc(entity->rq->sched->score); > + if (!single_entity) > + atomic_inc(entity->rq->sched->score); > WRITE_ONCE(entity->last_user, current->group_leader); > > /* > @@ -591,6 +625,10 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) > > /* first job wakes up scheduler */ > if (first) { > + struct drm_gpu_scheduler *sched = > + drm_sched_entity_to_scheduler(entity); > + bool fifo = sched->sched_policy == DRM_SCHED_POLICY_FIFO; > + > /* Add the entity to the run queue */ > spin_lock(&entity->rq_lock); > if (entity->stopped) { > @@ -600,13 +638,14 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) > return; > } > > - drm_sched_rq_add_entity(entity->rq, entity); > + if (!single_entity) > + drm_sched_rq_add_entity(entity->rq, entity); > spin_unlock(&entity->rq_lock); > > if (fifo) > drm_sched_rq_update_fifo(entity, submit_ts); > > - drm_sched_wakeup_if_can_queue(entity->rq->sched); > + drm_sched_wakeup_if_can_queue(sched); > } > } > EXPORT_SYMBOL(drm_sched_entity_push_job); > diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c > index 06cedfe4b486..f6b926f5e188 100644 > --- a/drivers/gpu/drm/scheduler/sched_fence.c > +++ b/drivers/gpu/drm/scheduler/sched_fence.c > @@ -225,7 +225,7 @@ void drm_sched_fence_init(struct drm_sched_fence *fence, > { > unsigned seq; > > - fence->sched = entity->rq->sched; > + fence->sched = drm_sched_entity_to_scheduler(entity); > seq = atomic_inc_return(&entity->fence_seq); > dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled, > &fence->lock, entity->fence_context, seq); > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c > index f645f32977ed..588c735f7498 100644 > --- a/drivers/gpu/drm/scheduler/sched_main.c > +++ b/drivers/gpu/drm/scheduler/sched_main.c > @@ -32,7 +32,8 @@ > * backend operations to the scheduler like submitting a job to hardware run queue, > * returning the dependencies of a job etc. > * > - * The organisation of the scheduler is the following: > + * The organisation of the scheduler is the following for scheduling policies > + * DRM_SCHED_POLICY_RR and DRM_SCHED_POLICY_FIFO: Yes, so this was badly written to begin with. If we're adding more information, I'd write: * For scheduling policies DRM_SCHED_POLICY_RR and DRM_SCHED_POLICY_FIFO, * the scheduler organization is, > * > * 1. Each hw run queue has one scheduler > * 2. Each scheduler has multiple run queues with different priorities > @@ -43,6 +44,23 @@ > * > * The jobs in a entity are always scheduled in the order that they were pushed. > * > + * The organisation of the scheduler is the following for scheduling policy > + * DRM_SCHED_POLICY_SINGLE_ENTITY: Remember, it's a list, on large enough scale, thus, * For DRM_SCHED_POLICY_SINGLE_ENTITY, the organization of the scheduler is, > + * > + * 1. One to one relationship between scheduler and entity > + * 2. No priorities implemented per scheduler (single job queue) > + * 3. No run queues in scheduler rather jobs are directly dequeued from entity > + * 4. The entity maintains a queue of jobs that will be scheduled on the > + * hardware Good! But please fix, 4. The entity maintains a queue of jobs that will be scheduler _to_ the hardware. > + * > + * The jobs in a entity are always scheduled in the order that they were pushed > + * regardless of scheduling policy. Please add here, Single-entity scheduling is essentially a FIFO for jobs. > + * > + * A policy of DRM_SCHED_POLICY_RR or DRM_SCHED_POLICY_FIFO is expected to used "... is expected to _be_ used ..." > + * when the KMD is scheduling directly on the hardware while a scheduling policy I'd spell out "kernel-mode driver" since it makes it terse when reading a processed DOC format, and having a three-letter abbreviation spelled out makes for an easier reading experience. (There are too many three-letter abbreviations as is...) "... directly _to_ the hardware ..." since, ultimately, the DRM scheduler just pushes jobs to be executed to the hardware by the hardware and doesn't support or control hardware preemption of jobs _on_ the hardware. (See what I did there? :-) ) > + * of DRM_SCHED_POLICY_SINGLE_ENTITY is expected to be used when there is a > + * firmware scheduler. > + * Yeah, so that's a good explanation--thanks for writing this. > * Note that once a job was taken from the entities queue and pushed to the Please only use present tense in software documentation. No past, future, or perfect tenses please. * Note that once a job _is_ taken from the entities queue and pushed to the > * hardware, i.e. the pending queue, the entity must not be referenced anymore > * through the jobs entity pointer. Yeah, another good explanation--thanks for including this. > @@ -96,6 +114,8 @@ static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *enti > > void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) > { > + WARN_ON(!!entity->single_sched); > + > /* > * Both locks need to be grabbed, one to protect from entity->rq change > * for entity from within concurrent drm_sched_entity_select_rq and the > @@ -126,6 +146,8 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) > static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, > struct drm_sched_rq *rq) > { > + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY); > + > spin_lock_init(&rq->lock); > INIT_LIST_HEAD(&rq->entities); > rq->rb_tree_root = RB_ROOT_CACHED; > @@ -144,6 +166,8 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, > void drm_sched_rq_add_entity(struct drm_sched_rq *rq, > struct drm_sched_entity *entity) > { > + WARN_ON(!!entity->single_sched); > + > if (!list_empty(&entity->list)) > return; > > @@ -166,6 +190,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq, > void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, > struct drm_sched_entity *entity) > { > + WARN_ON(!!entity->single_sched); > + > if (list_empty(&entity->list)) > return; > > @@ -641,7 +667,7 @@ int drm_sched_job_init(struct drm_sched_job *job, > struct drm_sched_entity *entity, > void *owner) > { > - if (!entity->rq) > + if (!entity->rq && !entity->single_sched) > return -ENOENT; > > job->entity = entity; > @@ -674,13 +700,16 @@ void drm_sched_job_arm(struct drm_sched_job *job) > { > struct drm_gpu_scheduler *sched; > struct drm_sched_entity *entity = job->entity; > + bool single_entity = !!entity->single_sched; > > BUG_ON(!entity); > - drm_sched_entity_select_rq(entity); > - sched = entity->rq->sched; > + if (!single_entity) > + drm_sched_entity_select_rq(entity); > + sched = drm_sched_entity_to_scheduler(entity); So here, I wonder, and I've a tiny exploratory request: Could we "fake" an rq for the single-entity and thus remove (become unnecessary) all those "if (single-entity)" and "if (!single-entity)". If we keep adding code peppered with if () everywhere, over the years it'll become hard to read. However, if we use maps to achieve choice and selection, such as entity->rq, then you'd not need much of the "if (single-entity)" and "if (!single-entity)", and the code would naturally stay mostly the same and the sched selection would still be abstracted out via the entity->rq. What do you think? > > job->sched = sched; > - job->s_priority = entity->rq - sched->sched_rq; > + if (!single_entity) > + job->s_priority = entity->rq - sched->sched_rq; > job->id = atomic64_inc_return(&sched->job_id_count); > > drm_sched_fence_init(job->s_fence, job->entity); > @@ -896,6 +925,14 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched) > if (!drm_sched_can_queue(sched)) > return NULL; > > + if (sched->single_entity) { > + if (!READ_ONCE(sched->single_entity->stopped) && > + drm_sched_entity_is_ready(sched->single_entity)) > + return sched->single_entity; > + > + return NULL; > + } > + > /* Kernel run queue has higher priority than normal run queue*/ > for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { > entity = sched->sched_policy == DRM_SCHED_POLICY_FIFO ? > @@ -1092,6 +1129,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, > return -EINVAL; > > sched->ops = ops; > + sched->single_entity = NULL; > sched->hw_submission_limit = hw_submission; > sched->name = name; > if (!submit_wq) { > @@ -1111,7 +1149,9 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, > sched->dev = dev; > sched->sched_policy = sched_policy == DRM_SCHED_POLICY_UNSET ? > drm_sched_policy_default : sched_policy; > - for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++) > + for (i = DRM_SCHED_PRIORITY_MIN; sched_policy != > + DRM_SCHED_POLICY_SINGLE_ENTITY && i < DRM_SCHED_PRIORITY_COUNT; > + i++) So, "sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY" doesn't seem to be a loop-invariant, since it doesn't cause the loop to exit over iterations. It's just a gate to executing the loop. I am used to seeing only loop invariants in the for-loop conditional. I wonder if it is clearer to just say what is meant: if (sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY) { for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++) ... } On a larger scheme of things, I believe it is a bit presumptuous to say: struct drm_gpu_scheduler { ... struct drm_sched_rq sched_rq[DRM_SCHED_PRIORITY_COUNT]; ... }; I mean, why does a scheduler have to implement all those priorities? Maybe it wants to implement only one. :-) Perhaps we can have, struct drm_gpu_scheduler { ... u32 num_rqs; struct drm_sched_rq *sched_rq; ... }; Which might make it easier to fake out an rq for single-entity and then leave the code mostly intact, while also implementing single-entity. It's not a gating issue, but perhaps it would create a cleaner code in the long run? Maybe we should explore this? > drm_sched_rq_init(sched, &sched->sched_rq[i]); > > init_waitqueue_head(&sched->job_scheduled); > @@ -1143,7 +1183,15 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched) > > drm_sched_submit_stop(sched); > > - for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { > + if (sched->single_entity) { > + spin_lock(&sched->single_entity->rq_lock); > + sched->single_entity->stopped = true; > + spin_unlock(&sched->single_entity->rq_lock); > + } > + > + for (i = DRM_SCHED_PRIORITY_COUNT - 1; sched->sched_policy != > + DRM_SCHED_POLICY_SINGLE_ENTITY && i >= DRM_SCHED_PRIORITY_MIN; > + i--) { > struct drm_sched_rq *rq = &sched->sched_rq[i]; Same sentiment here, as above.
On Wed, Sep 27, 2023 at 10:36:49AM -0400, Luben Tuikov wrote: > Hi, > > On 2023-09-19 01:01, Matthew Brost wrote: > > DRM_SCHED_POLICY_SINGLE_ENTITY creates a 1 to 1 relationship between > > scheduler and entity. No priorities or run queue used in this mode. > > Intended for devices with firmware schedulers. > > > > v2: > > - Drop sched / rq union (Luben) > > v3: > > - Don't pick entity if stopped in drm_sched_select_entity (Danilo) > > > > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > > --- > > drivers/gpu/drm/scheduler/sched_entity.c | 69 ++++++++++++++++++------ > > drivers/gpu/drm/scheduler/sched_fence.c | 2 +- > > drivers/gpu/drm/scheduler/sched_main.c | 64 +++++++++++++++++++--- > > include/drm/gpu_scheduler.h | 8 +++ > > 4 files changed, 120 insertions(+), 23 deletions(-) > > > > diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c > > index cf42e2265d64..437c50867c99 100644 > > --- a/drivers/gpu/drm/scheduler/sched_entity.c > > +++ b/drivers/gpu/drm/scheduler/sched_entity.c > > @@ -83,6 +83,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, > > memset(entity, 0, sizeof(struct drm_sched_entity)); > > INIT_LIST_HEAD(&entity->list); > > entity->rq = NULL; > > + entity->single_sched = NULL; > > entity->guilty = guilty; > > entity->num_sched_list = num_sched_list; > > entity->priority = priority; > > @@ -90,8 +91,17 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, > > RCU_INIT_POINTER(entity->last_scheduled, NULL); > > RB_CLEAR_NODE(&entity->rb_tree_node); > > > > - if(num_sched_list) > > - entity->rq = &sched_list[0]->sched_rq[entity->priority]; > > + if (num_sched_list) { > > + if (sched_list[0]->sched_policy != > > + DRM_SCHED_POLICY_SINGLE_ENTITY) { > > + entity->rq = &sched_list[0]->sched_rq[entity->priority]; > > + } else { > > + if (num_sched_list != 1 || sched_list[0]->single_entity) > > + return -EINVAL; > > + sched_list[0]->single_entity = entity; > > + entity->single_sched = sched_list[0]; > > + } > > + } > > So much (checking for) negativity...:-) > Perhaps the simplified form below? > > if (num_sched_list) { > if (sched_list[0]->sched_policy != > DRM_SCHED_POLICY_SINGLE_ENTITY) { > entity->rq = &sched_list[0]->sched_rq[entity->priority]; > } else if (num_sched_list == 1 && !sched_list[0]->single_entity) { > sched_list[0]->single_entity = entity; > entity->single_sched = sched_list[0]; > } else { > return -EINVAL; > } > } > Will change. > > > > init_completion(&entity->entity_idle); > > > > @@ -124,7 +134,8 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, > > struct drm_gpu_scheduler **sched_list, > > unsigned int num_sched_list) > > { > > - WARN_ON(!num_sched_list || !sched_list); > > + WARN_ON(!num_sched_list || !sched_list || > > + !!entity->single_sched); > > > > entity->sched_list = sched_list; > > entity->num_sched_list = num_sched_list; > > @@ -231,13 +242,15 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) > > { > > struct drm_sched_job *job; > > struct dma_fence *prev; > > + bool single_entity = !!entity->single_sched; > > > > - if (!entity->rq) > > + if (!entity->rq && !single_entity) > > return; > > > > spin_lock(&entity->rq_lock); > > entity->stopped = true; > > - drm_sched_rq_remove_entity(entity->rq, entity); > > + if (!single_entity) > > + drm_sched_rq_remove_entity(entity->rq, entity); > > spin_unlock(&entity->rq_lock); > > > > /* Make sure this entity is not used by the scheduler at the moment */ > > @@ -259,6 +272,20 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) > > dma_fence_put(prev); > > } > > > > +/** > > + * drm_sched_entity_to_scheduler - Schedule entity to GPU scheduler > > Please use verbs. Please? > > Fix: > /** > * drm_sched_entity_to_scheduler - Map a schedule entity to a GPU scheduler > > > + * @entity: scheduler entity > > + * > > + * Returns GPU scheduler for the entity > > Fix: > * Given an entity, return its GPU scheduler. > Yep. > > + */ > > +struct drm_gpu_scheduler * > > +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity) > > +{ > > + bool single_entity = !!entity->single_sched; > > + > > + return single_entity ? entity->single_sched : entity->rq->sched; > > +} > > + > > /** > > * drm_sched_entity_flush - Flush a context entity > > * > > @@ -276,11 +303,12 @@ long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout) > > struct drm_gpu_scheduler *sched; > > struct task_struct *last_user; > > long ret = timeout; > > + bool single_entity = !!entity->single_sched; > > > > - if (!entity->rq) > > + if (!entity->rq && !single_entity) > > return 0; > > > > - sched = entity->rq->sched; > > + sched = drm_sched_entity_to_scheduler(entity); > > /** > > * The client will not queue more IBs during this fini, consume existing > > * queued IBs or discard them on SIGKILL > > @@ -373,7 +401,7 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, > > container_of(cb, struct drm_sched_entity, cb); > > > > drm_sched_entity_clear_dep(f, cb); > > - drm_sched_wakeup_if_can_queue(entity->rq->sched); > > + drm_sched_wakeup_if_can_queue(drm_sched_entity_to_scheduler(entity)); > > } > > > > /** > > @@ -387,6 +415,8 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, > > void drm_sched_entity_set_priority(struct drm_sched_entity *entity, > > enum drm_sched_priority priority) > > { > > + WARN_ON(!!entity->single_sched); > > + > > spin_lock(&entity->rq_lock); > > entity->priority = priority; > > spin_unlock(&entity->rq_lock); > > @@ -399,7 +429,7 @@ EXPORT_SYMBOL(drm_sched_entity_set_priority); > > */ > > static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) > > { > > - struct drm_gpu_scheduler *sched = entity->rq->sched; > > + struct drm_gpu_scheduler *sched = drm_sched_entity_to_scheduler(entity); > > struct dma_fence *fence = entity->dependency; > > struct drm_sched_fence *s_fence; > > > > @@ -501,7 +531,8 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) > > * Update the entity's location in the min heap according to > > * the timestamp of the next job, if any. > > */ > > - if (entity->rq->sched->sched_policy == DRM_SCHED_POLICY_FIFO) { > > + if (drm_sched_entity_to_scheduler(entity)->sched_policy == > > + DRM_SCHED_POLICY_FIFO) { > > struct drm_sched_job *next; > > > > next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); > > @@ -524,6 +555,8 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) > > struct drm_gpu_scheduler *sched; > > struct drm_sched_rq *rq; > > > > + WARN_ON(!!entity->single_sched); > > + > > /* single possible engine and already selected */ > > if (!entity->sched_list) > > return; > > @@ -573,12 +606,13 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) > > void drm_sched_entity_push_job(struct drm_sched_job *sched_job) > > { > > struct drm_sched_entity *entity = sched_job->entity; > > - bool first, fifo = entity->rq->sched->sched_policy == > > - DRM_SCHED_POLICY_FIFO; > > + bool single_entity = !!entity->single_sched; > > + bool first; > > ktime_t submit_ts; > > > > trace_drm_sched_job(sched_job, entity); > > - atomic_inc(entity->rq->sched->score); > > + if (!single_entity) > > + atomic_inc(entity->rq->sched->score); > > WRITE_ONCE(entity->last_user, current->group_leader); > > > > /* > > @@ -591,6 +625,10 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) > > > > /* first job wakes up scheduler */ > > if (first) { > > + struct drm_gpu_scheduler *sched = > > + drm_sched_entity_to_scheduler(entity); > > + bool fifo = sched->sched_policy == DRM_SCHED_POLICY_FIFO; > > + > > /* Add the entity to the run queue */ > > spin_lock(&entity->rq_lock); > > if (entity->stopped) { > > @@ -600,13 +638,14 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) > > return; > > } > > > > - drm_sched_rq_add_entity(entity->rq, entity); > > + if (!single_entity) > > + drm_sched_rq_add_entity(entity->rq, entity); > > spin_unlock(&entity->rq_lock); > > > > if (fifo) > > drm_sched_rq_update_fifo(entity, submit_ts); > > > > - drm_sched_wakeup_if_can_queue(entity->rq->sched); > > + drm_sched_wakeup_if_can_queue(sched); > > } > > } > > EXPORT_SYMBOL(drm_sched_entity_push_job); > > diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c > > index 06cedfe4b486..f6b926f5e188 100644 > > --- a/drivers/gpu/drm/scheduler/sched_fence.c > > +++ b/drivers/gpu/drm/scheduler/sched_fence.c > > @@ -225,7 +225,7 @@ void drm_sched_fence_init(struct drm_sched_fence *fence, > > { > > unsigned seq; > > > > - fence->sched = entity->rq->sched; > > + fence->sched = drm_sched_entity_to_scheduler(entity); > > seq = atomic_inc_return(&entity->fence_seq); > > dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled, > > &fence->lock, entity->fence_context, seq); > > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c > > index f645f32977ed..588c735f7498 100644 > > --- a/drivers/gpu/drm/scheduler/sched_main.c > > +++ b/drivers/gpu/drm/scheduler/sched_main.c > > @@ -32,7 +32,8 @@ > > * backend operations to the scheduler like submitting a job to hardware run queue, > > * returning the dependencies of a job etc. > > * > > - * The organisation of the scheduler is the following: > > + * The organisation of the scheduler is the following for scheduling policies > > + * DRM_SCHED_POLICY_RR and DRM_SCHED_POLICY_FIFO: > > Yes, so this was badly written to begin with. If we're adding more information, > I'd write: > > * For scheduling policies DRM_SCHED_POLICY_RR and DRM_SCHED_POLICY_FIFO, > * the scheduler organization is, Yep. > > > * > > * 1. Each hw run queue has one scheduler > > * 2. Each scheduler has multiple run queues with different priorities > > @@ -43,6 +44,23 @@ > > * > > * The jobs in a entity are always scheduled in the order that they were pushed. > > * > > + * The organisation of the scheduler is the following for scheduling policy > > + * DRM_SCHED_POLICY_SINGLE_ENTITY: > > Remember, it's a list, on large enough scale, thus, > > * For DRM_SCHED_POLICY_SINGLE_ENTITY, the organization of the scheduler is, > > > + * > > + * 1. One to one relationship between scheduler and entity > > + * 2. No priorities implemented per scheduler (single job queue) > > + * 3. No run queues in scheduler rather jobs are directly dequeued from entity > > + * 4. The entity maintains a queue of jobs that will be scheduled on the > > + * hardware > > Good! But please fix, > > 4. The entity maintains a queue of jobs that will be scheduler _to_ the hardware. > > > + * > > + * The jobs in a entity are always scheduled in the order that they were pushed > > + * regardless of scheduling policy. > > Please add here, > Single-entity scheduling is essentially a FIFO for jobs. > > > + * > > + * A policy of DRM_SCHED_POLICY_RR or DRM_SCHED_POLICY_FIFO is expected to used > > "... is expected to _be_ used ..." > > > + * when the KMD is scheduling directly on the hardware while a scheduling policy > > I'd spell out "kernel-mode driver" since it makes it terse when reading a processed > DOC format, and having a three-letter abbreviation spelled out makes for an easier > reading experience. (There are too many three-letter abbreviations as is...) > > "... directly _to_ the hardware ..." since, ultimately, the DRM scheduler just > pushes jobs to be executed to the hardware by the hardware and doesn't support > or control hardware preemption of jobs _on_ the hardware. (See what I did there? :-) ) > > > + * of DRM_SCHED_POLICY_SINGLE_ENTITY is expected to be used when there is a > > + * firmware scheduler. > > + * > > Yeah, so that's a good explanation--thanks for writing this. > > > * Note that once a job was taken from the entities queue and pushed to the > > Please only use present tense in software documentation. No past, future, or > perfect tenses please. > > * Note that once a job _is_ taken from the entities queue and pushed to the > > > * hardware, i.e. the pending queue, the entity must not be referenced anymore > > * through the jobs entity pointer. > > Yeah, another good explanation--thanks for including this. > Yes to all the wordin changes. > > @@ -96,6 +114,8 @@ static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *enti > > > > void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) > > { > > + WARN_ON(!!entity->single_sched); > > + > > /* > > * Both locks need to be grabbed, one to protect from entity->rq change > > * for entity from within concurrent drm_sched_entity_select_rq and the > > @@ -126,6 +146,8 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) > > static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, > > struct drm_sched_rq *rq) > > { > > + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY); > > + > > spin_lock_init(&rq->lock); > > INIT_LIST_HEAD(&rq->entities); > > rq->rb_tree_root = RB_ROOT_CACHED; > > @@ -144,6 +166,8 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, > > void drm_sched_rq_add_entity(struct drm_sched_rq *rq, > > struct drm_sched_entity *entity) > > { > > + WARN_ON(!!entity->single_sched); > > + > > if (!list_empty(&entity->list)) > > return; > > > > @@ -166,6 +190,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq, > > void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, > > struct drm_sched_entity *entity) > > { > > + WARN_ON(!!entity->single_sched); > > + > > if (list_empty(&entity->list)) > > return; > > > > @@ -641,7 +667,7 @@ int drm_sched_job_init(struct drm_sched_job *job, > > struct drm_sched_entity *entity, > > void *owner) > > { > > - if (!entity->rq) > > + if (!entity->rq && !entity->single_sched) > > return -ENOENT; > > > > job->entity = entity; > > @@ -674,13 +700,16 @@ void drm_sched_job_arm(struct drm_sched_job *job) > > { > > struct drm_gpu_scheduler *sched; > > struct drm_sched_entity *entity = job->entity; > > + bool single_entity = !!entity->single_sched; > > > > BUG_ON(!entity); > > - drm_sched_entity_select_rq(entity); > > - sched = entity->rq->sched; > > + if (!single_entity) > > + drm_sched_entity_select_rq(entity); > > + sched = drm_sched_entity_to_scheduler(entity); > > So here, I wonder, and I've a tiny exploratory request: > Could we "fake" an rq for the single-entity and thus remove (become unnecessary) > all those "if (single-entity)" and "if (!single-entity)". > > If we keep adding code peppered with if () everywhere, over the years it'll become > hard to read. However, if we use maps to achieve choice and selection, such as entity->rq, > then you'd not need much of the "if (single-entity)" and "if (!single-entity)", > and the code would naturally stay mostly the same and the sched selection would > still be abstracted out via the entity->rq. > > What do you think? > I looked into this a little and can't really think of an easy way to do this. Wouldn't we just end up with a similar number of checks in the rq code? I'd say for now let's just live the if / else in a few places. If we start adding more scheduling modes then perhaps we explore another approach. > > > > job->sched = sched; > > - job->s_priority = entity->rq - sched->sched_rq; > > + if (!single_entity) > > + job->s_priority = entity->rq - sched->sched_rq; > > job->id = atomic64_inc_return(&sched->job_id_count); > > > > drm_sched_fence_init(job->s_fence, job->entity); > > @@ -896,6 +925,14 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched) > > if (!drm_sched_can_queue(sched)) > > return NULL; > > > > + if (sched->single_entity) { > > + if (!READ_ONCE(sched->single_entity->stopped) && > > + drm_sched_entity_is_ready(sched->single_entity)) > > + return sched->single_entity; > > + > > + return NULL; > > + } > > + > > /* Kernel run queue has higher priority than normal run queue*/ > > for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { > > entity = sched->sched_policy == DRM_SCHED_POLICY_FIFO ? > > @@ -1092,6 +1129,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, > > return -EINVAL; > > > > sched->ops = ops; > > + sched->single_entity = NULL; > > sched->hw_submission_limit = hw_submission; > > sched->name = name; > > if (!submit_wq) { > > @@ -1111,7 +1149,9 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, > > sched->dev = dev; > > sched->sched_policy = sched_policy == DRM_SCHED_POLICY_UNSET ? > > drm_sched_policy_default : sched_policy; > > - for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++) > > + for (i = DRM_SCHED_PRIORITY_MIN; sched_policy != > > + DRM_SCHED_POLICY_SINGLE_ENTITY && i < DRM_SCHED_PRIORITY_COUNT; > > + i++) > > So, "sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY" doesn't seem to be > a loop-invariant, since it doesn't cause the loop to exit over iterations. > It's just a gate to executing the loop. I am used to seeing only loop > invariants in the for-loop conditional. > > I wonder if it is clearer to just say what is meant: > > if (sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY) { > for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++) > ... > } > Sure, will add if statement. > On a larger scheme of things, I believe it is a bit presumptuous to say: > > struct drm_gpu_scheduler { > ... > struct drm_sched_rq sched_rq[DRM_SCHED_PRIORITY_COUNT]; > ... > }; > > I mean, why does a scheduler have to implement all those priorities? Maybe it > wants to implement only one. :-) > > Perhaps we can have, > > struct drm_gpu_scheduler { > ... > u32 num_rqs; > struct drm_sched_rq *sched_rq; > ... > }; > > Which might make it easier to fake out an rq for single-entity and then leave > the code mostly intact, while also implementing single-entity. > > It's not a gating issue, but perhaps it would create a cleaner code in the long > run? Maybe we should explore this? > See above. I'd vote for leave this as is for now. > > drm_sched_rq_init(sched, &sched->sched_rq[i]); > > > > init_waitqueue_head(&sched->job_scheduled); > > @@ -1143,7 +1183,15 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched) > > > > drm_sched_submit_stop(sched); > > > > - for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { > > + if (sched->single_entity) { > > + spin_lock(&sched->single_entity->rq_lock); > > + sched->single_entity->stopped = true; > > + spin_unlock(&sched->single_entity->rq_lock); > > + } > > + > > + for (i = DRM_SCHED_PRIORITY_COUNT - 1; sched->sched_policy != > > + DRM_SCHED_POLICY_SINGLE_ENTITY && i >= DRM_SCHED_PRIORITY_MIN; > > + i--) { > > struct drm_sched_rq *rq = &sched->sched_rq[i]; > > Same sentiment here, as above. Got it. Matt > -- > Regards, > Luben > > > > > spin_lock(&rq->lock); > > @@ -1186,6 +1234,8 @@ void drm_sched_increase_karma(struct drm_sched_job *bad) > > struct drm_sched_entity *entity; > > struct drm_gpu_scheduler *sched = bad->sched; > > > > + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY); > > + > > /* don't change @bad's karma if it's from KERNEL RQ, > > * because sometimes GPU hang would cause kernel jobs (like VM updating jobs) > > * corrupt but keep in mind that kernel jobs always considered good. > > diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h > > index 9f830ff84bad..655675f797ea 100644 > > --- a/include/drm/gpu_scheduler.h > > +++ b/include/drm/gpu_scheduler.h > > @@ -79,6 +79,7 @@ enum drm_sched_policy { > > DRM_SCHED_POLICY_UNSET, > > DRM_SCHED_POLICY_RR, > > DRM_SCHED_POLICY_FIFO, > > + DRM_SCHED_POLICY_SINGLE_ENTITY, > > DRM_SCHED_POLICY_COUNT, > > }; > > > > @@ -112,6 +113,9 @@ struct drm_sched_entity { > > */ > > struct drm_sched_rq *rq; > > > > + /** @single_sched: Single scheduler */ > > + struct drm_gpu_scheduler *single_sched; > > + > > /** > > * @sched_list: > > * > > @@ -473,6 +477,7 @@ struct drm_sched_backend_ops { > > * struct drm_gpu_scheduler - scheduler instance-specific data > > * > > * @ops: backend operations provided by the driver. > > + * @single_entity: Single entity for the scheduler > > * @hw_submission_limit: the max size of the hardware queue. > > * @timeout: the time after which a job is removed from the scheduler. > > * @name: name of the ring for which this scheduler is being used. > > @@ -504,6 +509,7 @@ struct drm_sched_backend_ops { > > */ > > struct drm_gpu_scheduler { > > const struct drm_sched_backend_ops *ops; > > + struct drm_sched_entity *single_entity; > > uint32_t hw_submission_limit; > > long timeout; > > const char *name; > > @@ -587,6 +593,8 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, > > struct drm_gpu_scheduler **sched_list, > > unsigned int num_sched_list, > > atomic_t *guilty); > > +struct drm_gpu_scheduler * > > +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity); > > long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout); > > void drm_sched_entity_fini(struct drm_sched_entity *entity); > > void drm_sched_entity_destroy(struct drm_sched_entity *entity); >
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index cf42e2265d64..437c50867c99 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -83,6 +83,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, memset(entity, 0, sizeof(struct drm_sched_entity)); INIT_LIST_HEAD(&entity->list); entity->rq = NULL; + entity->single_sched = NULL; entity->guilty = guilty; entity->num_sched_list = num_sched_list; entity->priority = priority; @@ -90,8 +91,17 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, RCU_INIT_POINTER(entity->last_scheduled, NULL); RB_CLEAR_NODE(&entity->rb_tree_node); - if(num_sched_list) - entity->rq = &sched_list[0]->sched_rq[entity->priority]; + if (num_sched_list) { + if (sched_list[0]->sched_policy != + DRM_SCHED_POLICY_SINGLE_ENTITY) { + entity->rq = &sched_list[0]->sched_rq[entity->priority]; + } else { + if (num_sched_list != 1 || sched_list[0]->single_entity) + return -EINVAL; + sched_list[0]->single_entity = entity; + entity->single_sched = sched_list[0]; + } + } init_completion(&entity->entity_idle); @@ -124,7 +134,8 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity, struct drm_gpu_scheduler **sched_list, unsigned int num_sched_list) { - WARN_ON(!num_sched_list || !sched_list); + WARN_ON(!num_sched_list || !sched_list || + !!entity->single_sched); entity->sched_list = sched_list; entity->num_sched_list = num_sched_list; @@ -231,13 +242,15 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) { struct drm_sched_job *job; struct dma_fence *prev; + bool single_entity = !!entity->single_sched; - if (!entity->rq) + if (!entity->rq && !single_entity) return; spin_lock(&entity->rq_lock); entity->stopped = true; - drm_sched_rq_remove_entity(entity->rq, entity); + if (!single_entity) + drm_sched_rq_remove_entity(entity->rq, entity); spin_unlock(&entity->rq_lock); /* Make sure this entity is not used by the scheduler at the moment */ @@ -259,6 +272,20 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) dma_fence_put(prev); } +/** + * drm_sched_entity_to_scheduler - Schedule entity to GPU scheduler + * @entity: scheduler entity + * + * Returns GPU scheduler for the entity + */ +struct drm_gpu_scheduler * +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity) +{ + bool single_entity = !!entity->single_sched; + + return single_entity ? entity->single_sched : entity->rq->sched; +} + /** * drm_sched_entity_flush - Flush a context entity * @@ -276,11 +303,12 @@ long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout) struct drm_gpu_scheduler *sched; struct task_struct *last_user; long ret = timeout; + bool single_entity = !!entity->single_sched; - if (!entity->rq) + if (!entity->rq && !single_entity) return 0; - sched = entity->rq->sched; + sched = drm_sched_entity_to_scheduler(entity); /** * The client will not queue more IBs during this fini, consume existing * queued IBs or discard them on SIGKILL @@ -373,7 +401,7 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, container_of(cb, struct drm_sched_entity, cb); drm_sched_entity_clear_dep(f, cb); - drm_sched_wakeup_if_can_queue(entity->rq->sched); + drm_sched_wakeup_if_can_queue(drm_sched_entity_to_scheduler(entity)); } /** @@ -387,6 +415,8 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, void drm_sched_entity_set_priority(struct drm_sched_entity *entity, enum drm_sched_priority priority) { + WARN_ON(!!entity->single_sched); + spin_lock(&entity->rq_lock); entity->priority = priority; spin_unlock(&entity->rq_lock); @@ -399,7 +429,7 @@ EXPORT_SYMBOL(drm_sched_entity_set_priority); */ static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) { - struct drm_gpu_scheduler *sched = entity->rq->sched; + struct drm_gpu_scheduler *sched = drm_sched_entity_to_scheduler(entity); struct dma_fence *fence = entity->dependency; struct drm_sched_fence *s_fence; @@ -501,7 +531,8 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) * Update the entity's location in the min heap according to * the timestamp of the next job, if any. */ - if (entity->rq->sched->sched_policy == DRM_SCHED_POLICY_FIFO) { + if (drm_sched_entity_to_scheduler(entity)->sched_policy == + DRM_SCHED_POLICY_FIFO) { struct drm_sched_job *next; next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); @@ -524,6 +555,8 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) struct drm_gpu_scheduler *sched; struct drm_sched_rq *rq; + WARN_ON(!!entity->single_sched); + /* single possible engine and already selected */ if (!entity->sched_list) return; @@ -573,12 +606,13 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) void drm_sched_entity_push_job(struct drm_sched_job *sched_job) { struct drm_sched_entity *entity = sched_job->entity; - bool first, fifo = entity->rq->sched->sched_policy == - DRM_SCHED_POLICY_FIFO; + bool single_entity = !!entity->single_sched; + bool first; ktime_t submit_ts; trace_drm_sched_job(sched_job, entity); - atomic_inc(entity->rq->sched->score); + if (!single_entity) + atomic_inc(entity->rq->sched->score); WRITE_ONCE(entity->last_user, current->group_leader); /* @@ -591,6 +625,10 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) /* first job wakes up scheduler */ if (first) { + struct drm_gpu_scheduler *sched = + drm_sched_entity_to_scheduler(entity); + bool fifo = sched->sched_policy == DRM_SCHED_POLICY_FIFO; + /* Add the entity to the run queue */ spin_lock(&entity->rq_lock); if (entity->stopped) { @@ -600,13 +638,14 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job) return; } - drm_sched_rq_add_entity(entity->rq, entity); + if (!single_entity) + drm_sched_rq_add_entity(entity->rq, entity); spin_unlock(&entity->rq_lock); if (fifo) drm_sched_rq_update_fifo(entity, submit_ts); - drm_sched_wakeup_if_can_queue(entity->rq->sched); + drm_sched_wakeup_if_can_queue(sched); } } EXPORT_SYMBOL(drm_sched_entity_push_job); diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c index 06cedfe4b486..f6b926f5e188 100644 --- a/drivers/gpu/drm/scheduler/sched_fence.c +++ b/drivers/gpu/drm/scheduler/sched_fence.c @@ -225,7 +225,7 @@ void drm_sched_fence_init(struct drm_sched_fence *fence, { unsigned seq; - fence->sched = entity->rq->sched; + fence->sched = drm_sched_entity_to_scheduler(entity); seq = atomic_inc_return(&entity->fence_seq); dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled, &fence->lock, entity->fence_context, seq); diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index f645f32977ed..588c735f7498 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -32,7 +32,8 @@ * backend operations to the scheduler like submitting a job to hardware run queue, * returning the dependencies of a job etc. * - * The organisation of the scheduler is the following: + * The organisation of the scheduler is the following for scheduling policies + * DRM_SCHED_POLICY_RR and DRM_SCHED_POLICY_FIFO: * * 1. Each hw run queue has one scheduler * 2. Each scheduler has multiple run queues with different priorities @@ -43,6 +44,23 @@ * * The jobs in a entity are always scheduled in the order that they were pushed. * + * The organisation of the scheduler is the following for scheduling policy + * DRM_SCHED_POLICY_SINGLE_ENTITY: + * + * 1. One to one relationship between scheduler and entity + * 2. No priorities implemented per scheduler (single job queue) + * 3. No run queues in scheduler rather jobs are directly dequeued from entity + * 4. The entity maintains a queue of jobs that will be scheduled on the + * hardware + * + * The jobs in a entity are always scheduled in the order that they were pushed + * regardless of scheduling policy. + * + * A policy of DRM_SCHED_POLICY_RR or DRM_SCHED_POLICY_FIFO is expected to used + * when the KMD is scheduling directly on the hardware while a scheduling policy + * of DRM_SCHED_POLICY_SINGLE_ENTITY is expected to be used when there is a + * firmware scheduler. + * * Note that once a job was taken from the entities queue and pushed to the * hardware, i.e. the pending queue, the entity must not be referenced anymore * through the jobs entity pointer. @@ -96,6 +114,8 @@ static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *enti void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) { + WARN_ON(!!entity->single_sched); + /* * Both locks need to be grabbed, one to protect from entity->rq change * for entity from within concurrent drm_sched_entity_select_rq and the @@ -126,6 +146,8 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts) static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, struct drm_sched_rq *rq) { + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY); + spin_lock_init(&rq->lock); INIT_LIST_HEAD(&rq->entities); rq->rb_tree_root = RB_ROOT_CACHED; @@ -144,6 +166,8 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler *sched, void drm_sched_rq_add_entity(struct drm_sched_rq *rq, struct drm_sched_entity *entity) { + WARN_ON(!!entity->single_sched); + if (!list_empty(&entity->list)) return; @@ -166,6 +190,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq, void drm_sched_rq_remove_entity(struct drm_sched_rq *rq, struct drm_sched_entity *entity) { + WARN_ON(!!entity->single_sched); + if (list_empty(&entity->list)) return; @@ -641,7 +667,7 @@ int drm_sched_job_init(struct drm_sched_job *job, struct drm_sched_entity *entity, void *owner) { - if (!entity->rq) + if (!entity->rq && !entity->single_sched) return -ENOENT; job->entity = entity; @@ -674,13 +700,16 @@ void drm_sched_job_arm(struct drm_sched_job *job) { struct drm_gpu_scheduler *sched; struct drm_sched_entity *entity = job->entity; + bool single_entity = !!entity->single_sched; BUG_ON(!entity); - drm_sched_entity_select_rq(entity); - sched = entity->rq->sched; + if (!single_entity) + drm_sched_entity_select_rq(entity); + sched = drm_sched_entity_to_scheduler(entity); job->sched = sched; - job->s_priority = entity->rq - sched->sched_rq; + if (!single_entity) + job->s_priority = entity->rq - sched->sched_rq; job->id = atomic64_inc_return(&sched->job_id_count); drm_sched_fence_init(job->s_fence, job->entity); @@ -896,6 +925,14 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched) if (!drm_sched_can_queue(sched)) return NULL; + if (sched->single_entity) { + if (!READ_ONCE(sched->single_entity->stopped) && + drm_sched_entity_is_ready(sched->single_entity)) + return sched->single_entity; + + return NULL; + } + /* Kernel run queue has higher priority than normal run queue*/ for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { entity = sched->sched_policy == DRM_SCHED_POLICY_FIFO ? @@ -1092,6 +1129,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, return -EINVAL; sched->ops = ops; + sched->single_entity = NULL; sched->hw_submission_limit = hw_submission; sched->name = name; if (!submit_wq) { @@ -1111,7 +1149,9 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, sched->dev = dev; sched->sched_policy = sched_policy == DRM_SCHED_POLICY_UNSET ? drm_sched_policy_default : sched_policy; - for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++) + for (i = DRM_SCHED_PRIORITY_MIN; sched_policy != + DRM_SCHED_POLICY_SINGLE_ENTITY && i < DRM_SCHED_PRIORITY_COUNT; + i++) drm_sched_rq_init(sched, &sched->sched_rq[i]); init_waitqueue_head(&sched->job_scheduled); @@ -1143,7 +1183,15 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched) drm_sched_submit_stop(sched); - for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { + if (sched->single_entity) { + spin_lock(&sched->single_entity->rq_lock); + sched->single_entity->stopped = true; + spin_unlock(&sched->single_entity->rq_lock); + } + + for (i = DRM_SCHED_PRIORITY_COUNT - 1; sched->sched_policy != + DRM_SCHED_POLICY_SINGLE_ENTITY && i >= DRM_SCHED_PRIORITY_MIN; + i--) { struct drm_sched_rq *rq = &sched->sched_rq[i]; spin_lock(&rq->lock); @@ -1186,6 +1234,8 @@ void drm_sched_increase_karma(struct drm_sched_job *bad) struct drm_sched_entity *entity; struct drm_gpu_scheduler *sched = bad->sched; + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY); + /* don't change @bad's karma if it's from KERNEL RQ, * because sometimes GPU hang would cause kernel jobs (like VM updating jobs) * corrupt but keep in mind that kernel jobs always considered good. diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index 9f830ff84bad..655675f797ea 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -79,6 +79,7 @@ enum drm_sched_policy { DRM_SCHED_POLICY_UNSET, DRM_SCHED_POLICY_RR, DRM_SCHED_POLICY_FIFO, + DRM_SCHED_POLICY_SINGLE_ENTITY, DRM_SCHED_POLICY_COUNT, }; @@ -112,6 +113,9 @@ struct drm_sched_entity { */ struct drm_sched_rq *rq; + /** @single_sched: Single scheduler */ + struct drm_gpu_scheduler *single_sched; + /** * @sched_list: * @@ -473,6 +477,7 @@ struct drm_sched_backend_ops { * struct drm_gpu_scheduler - scheduler instance-specific data * * @ops: backend operations provided by the driver. + * @single_entity: Single entity for the scheduler * @hw_submission_limit: the max size of the hardware queue. * @timeout: the time after which a job is removed from the scheduler. * @name: name of the ring for which this scheduler is being used. @@ -504,6 +509,7 @@ struct drm_sched_backend_ops { */ struct drm_gpu_scheduler { const struct drm_sched_backend_ops *ops; + struct drm_sched_entity *single_entity; uint32_t hw_submission_limit; long timeout; const char *name; @@ -587,6 +593,8 @@ int drm_sched_entity_init(struct drm_sched_entity *entity, struct drm_gpu_scheduler **sched_list, unsigned int num_sched_list, atomic_t *guilty); +struct drm_gpu_scheduler * +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity); long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout); void drm_sched_entity_fini(struct drm_sched_entity *entity); void drm_sched_entity_destroy(struct drm_sched_entity *entity);
DRM_SCHED_POLICY_SINGLE_ENTITY creates a 1 to 1 relationship between scheduler and entity. No priorities or run queue used in this mode. Intended for devices with firmware schedulers. v2: - Drop sched / rq union (Luben) v3: - Don't pick entity if stopped in drm_sched_select_entity (Danilo) Signed-off-by: Matthew Brost <matthew.brost@intel.com> --- drivers/gpu/drm/scheduler/sched_entity.c | 69 ++++++++++++++++++------ drivers/gpu/drm/scheduler/sched_fence.c | 2 +- drivers/gpu/drm/scheduler/sched_main.c | 64 +++++++++++++++++++--- include/drm/gpu_scheduler.h | 8 +++ 4 files changed, 120 insertions(+), 23 deletions(-)