[PATCH v6 4/7] drm/sched: Add DRM_SCHED_POLICY_SINGLE_ENTITY scheduling policy
Matthew Brost
matthew.brost at intel.com
Tue Oct 17 15:09:55 UTC 2023
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)
v4:
- Rework if statement in drm_sched_entity_init (Luben)
- Update comment for drm_sched_entity_to_scheduler (Luben)
- Reword a few things in DOC comment (Luben)
- Do not check sched policy in for statement (Luben)
v5:
- Fix extra blank lines (Luben / Checkpatch)
Signed-off-by: Matthew Brost <matthew.brost at 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 | 87 ++++++++++++++++++------
include/drm/gpu_scheduler.h | 8 +++
4 files changed, 130 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index cf42e2265d64..940f63dd6965 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) {
+ 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
+ * @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 150e5330f0fa..273e0fbc4eab 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:
+ * 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
@@ -43,7 +44,24 @@
*
* The jobs in a entity are always scheduled in the order that they were pushed.
*
- * Note that once a job was taken from the entities queue and pushed to the
+ * 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 to the
+ * hardware
+ *
+ * The jobs in a entity are always scheduled in the order that they were pushed
+ * regardless of scheduling policy. Single-entity scheduling is essentially a
+ * FIFO for jobs.
+ *
+ * A policy of DRM_SCHED_POLICY_RR or DRM_SCHED_POLICY_FIFO is expected to be
+ * used when the kernel-mode driver is scheduling directly to 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 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.
*/
@@ -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) {
@@ -1111,8 +1149,10 @@ 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++)
- drm_sched_rq_init(sched, &sched->sched_rq[i]);
+ if (sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY) {
+ for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++)
+ drm_sched_rq_init(sched, &sched->sched_rq[i]);
+ }
init_waitqueue_head(&sched->job_scheduled);
INIT_LIST_HEAD(&sched->pending_list);
@@ -1143,19 +1183,24 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched)
drm_sched_wqueue_stop(sched);
- for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
- struct drm_sched_rq *rq = &sched->sched_rq[i];
-
- spin_lock(&rq->lock);
- list_for_each_entry(s_entity, &rq->entities, list)
- /*
- * Prevents reinsertion and marks job_queue as idle,
- * it will removed from rq in drm_sched_entity_fini
- * eventually
- */
- s_entity->stopped = true;
- spin_unlock(&rq->lock);
+ if (sched->single_entity) {
+ spin_lock(&sched->single_entity->rq_lock);
+ sched->single_entity->stopped = true;
+ spin_unlock(&sched->single_entity->rq_lock);
+ } else if (sched->sched_policy != DRM_SCHED_POLICY_SINGLE_ENTITY) {
+ for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
+ struct drm_sched_rq *rq = &sched->sched_rq[i];
+ spin_lock(&rq->lock);
+ list_for_each_entry(s_entity, &rq->entities, list)
+ /*
+ * Prevents reinsertion and marks job_queue as idle,
+ * it will removed from rq in drm_sched_entity_fini
+ * eventually
+ */
+ s_entity->stopped = true;
+ spin_unlock(&rq->lock);
+ }
}
/* Wakeup everyone stuck in drm_sched_entity_flush for this scheduler */
@@ -1186,6 +1231,8 @@ 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 320f0a720486..e67b53c3546b 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);
--
2.34.1
More information about the dri-devel
mailing list