Hi Matt,
On 2023-10-25 11:13, Matthew Brost wrote:
> On Mon, Oct 23, 2023 at 11:50:26PM -0400, Luben Tuikov wrote:
>> Hi,
>>
>> On 2023-10-17 11:09, 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)
>>> 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.br...@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];
>>
>> To simplify the rest of the GPU scheduler design and generalize the logic,
>> we can do
>> entity->rq = sched_list[0]->sched_rq[entity->priority];
>> where the "priority" is 0, thus having a single rq.
>>
>> We shouldn't splice scheduler and entity, but rather make it so that
>> we can set the number of rqs to 1, thus resulting in a single rq.
>>
>> (https://lore.kernel.org/r/20231023032251.164775-1-luben.tui...@amd.com)
>>
>
> I pulled out this patch [1] + previous one [2] and included your [3] to
> test this in Xe [4].
>
> It seems to work with just one rq per scheduler. We can go with this
> approach in feel like this is the route. My next post will include your
> patch [3] if we agree.
Yeah, this is good. Thanks!
I feel that the sched_rq[] static array should've been a dynamic one
from the outset--one of the hallmarks of a flexible scheduler. Then
let each driver announce how many priorities they care about. A scheduler
shouldn't be as rigid as to force drivers to care and/or support so and
so many run-queues (priorities).
For a good code design, we want to allow for more driver implementations
with minimal (or no) DRM changes--all accommodated by drm_sched_init(), yet,
accommodating a varied behaviour, and having the sched_rq be dynamic and let
each driver announce how many run-queues it wants is the minimal change we
can do now (and easiest), with best outcome for Xe and new drivers.
Regards,
Luben
>
> Matt
>
> [1] https://patchwork.freedesktop.org/patch/563094/?series=121745&rev=8
> [2] https://patchwork.freedesktop.org/patch/563093/?series=121745&rev=8
> [3] https://patchwork.freedesktop.org/patch/563817/?series=125433&rev=1
> [4] https://patchwork.freedesktop.org/series/125540/
>
>>> + } 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);
>>
>> We wouldn't need this check.
>>
>>>
>>> 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);
>>
>> We should be able to carry on the existing infrastructure when
>> having num_rqs = 1, with dynamic rqs. So we shouldn't warrant
>> any changes here.
>>
>>>
>>> /* 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;
>>
>> It would be "entity->rq->sched" for any and all cases which simplifies
>> things.
>>
>>> +}
>>> +
>>> /**
>>> * 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));
>>> }
>>
>> We can carry on that too, without changes. The good part of that is that
>> we'll inherit all the fence work and checking for free.
>>
>>>
>>> /**
>>> @@ -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]);
>>> + }
>>
>> With dynamic rq, no changes would be necessary here--we just go over the
>> single rq.
>>
>>>
>>> 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);
>>> + }
>>> }
>>
>> Same here--we can keep the loop intact, we have a single rq and we just
>> process it.
>>
>>>
>>> /* 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;
>>
>> Right, as I mentioned above, we shouldn't splice up between a scheduler
>> and an entity sometimes, and other times scheduler to rq to entity--it just
>> creates too much thrashing about in the code, with too many ifs, conditions,
>> etc. Simpler is better--parameterization of the number of rqs.
>>
>> Instead, let's get the dynamic rqs in, and this way we can keep much
>> of the code the same, inheriting fence work and checks, and so on,
>> without much changes.
>>
>> Regards,
>> Luben
>>
>>> 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);
>>
