[v4,03/18] drm/sched: Add dependency tracking
Commit Message
Instead of just a callback we can just glue in the gem helpers that
panfrost, v3d and lima currently use. There's really not that many
ways to skin this cat.
On the naming bikeshed: The idea for using _await_ to denote adding
dependencies to a job comes from i915, where that's used quite
extensively all over the place, in lots of datastructures.
v2/3: Rebased.
Reviewed-by: Steven Price <steven.price@arm.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Nirmoy Das <nirmoy.aiemd@gmail.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Jack Zhang <Jack.Zhang1@amd.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
---
drivers/gpu/drm/scheduler/sched_entity.c | 18 +++-
drivers/gpu/drm/scheduler/sched_main.c | 103 +++++++++++++++++++++++
include/drm/gpu_scheduler.h | 31 ++++++-
3 files changed, 146 insertions(+), 6 deletions(-)
Comments
Adding a few more people to this bikeshed.
On Mon, Jul 12, 2021 at 10:02 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> @@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job,
> struct drm_sched_entity *entity,
> void *owner);
> void drm_sched_job_arm(struct drm_sched_job *job);
> +int drm_sched_job_await_fence(struct drm_sched_job *job,
> + struct dma_fence *fence);
> +int drm_sched_job_await_implicit(struct drm_sched_job *job,
> + struct drm_gem_object *obj,
> + bool write);
> +
> +
I'm still waiting on the paint delivery for these two functions so I
can finish this shed.
Thanks, Daniel
> void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
> struct drm_gpu_scheduler **sched_list,
> unsigned int num_sched_list);
> --
> 2.32.0
>
Am 27.07.21 um 13:09 schrieb Daniel Vetter:
> Adding a few more people to this bikeshed.
>
> On Mon, Jul 12, 2021 at 10:02 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>
>> @@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job,
>> struct drm_sched_entity *entity,
>> void *owner);
>> void drm_sched_job_arm(struct drm_sched_job *job);
>> +int drm_sched_job_await_fence(struct drm_sched_job *job,
>> + struct dma_fence *fence);
>> +int drm_sched_job_await_implicit(struct drm_sched_job *job,
>> + struct drm_gem_object *obj,
>> + bool write);
>> +
>> +
> I'm still waiting on the paint delivery for these two functions so I
> can finish this shed.
Well I wouldn't call that bike shedding, good names are important.
Just imaging we would have called the exclusive-fence write-fence instead.
What speaks against calling them add_dependency() and
_add_implicit_depencencies() ?
Regards,
Christian.
>
> Thanks, Daniel
>
>> void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
>> struct drm_gpu_scheduler **sched_list,
>> unsigned int num_sched_list);
>> --
>> 2.32.0
>>
>
On Wed, Jul 28, 2021 at 1:29 PM Christian König
<ckoenig.leichtzumerken@gmail.com> wrote:
> Am 27.07.21 um 13:09 schrieb Daniel Vetter:
> > Adding a few more people to this bikeshed.
> >
> > On Mon, Jul 12, 2021 at 10:02 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> >
> >> @@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job,
> >> struct drm_sched_entity *entity,
> >> void *owner);
> >> void drm_sched_job_arm(struct drm_sched_job *job);
> >> +int drm_sched_job_await_fence(struct drm_sched_job *job,
> >> + struct dma_fence *fence);
> >> +int drm_sched_job_await_implicit(struct drm_sched_job *job,
> >> + struct drm_gem_object *obj,
> >> + bool write);
> >> +
> >> +
> > I'm still waiting on the paint delivery for these two functions so I
> > can finish this shed.
>
> Well I wouldn't call that bike shedding, good names are important.
>
> Just imaging we would have called the exclusive-fence write-fence instead.
Sure naming matters, but at least to my English understanding there's
not a semantic different between telling something to await for
something else (i.e. add a dependency) or to tell something to add a
dependency (i.e. await that thing later on before you start doing your
own thing).
Exclusive vs write fence otoh is a pretty big difference in what it means.
But also if there's consensus that I'm wrong then I'm happy to pick
the more preferred of the two options I deem equivalent.
> What speaks against calling them add_dependency() and
> _add_implicit_depencencies() ?
Nothing. I just like another ack on this before I rename it all. Also
I wasnt sure what you'd want to name the implicit dependency thing.
Lucas, Boris, Melissa, any acks here?
-Daniel
> Regards,
> Christian.
>
> >
> > Thanks, Daniel
> >
> >> void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
> >> struct drm_gpu_scheduler **sched_list,
> >> unsigned int num_sched_list);
> >> --
> >> 2.32.0
> >>
> >
>
Am 28.07.21 um 14:09 schrieb Daniel Vetter:
> On Wed, Jul 28, 2021 at 1:29 PM Christian König
> <ckoenig.leichtzumerken@gmail.com> wrote:
>> Am 27.07.21 um 13:09 schrieb Daniel Vetter:
>>> Adding a few more people to this bikeshed.
>>>
>>> On Mon, Jul 12, 2021 at 10:02 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>>>
>>>> @@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job,
>>>> struct drm_sched_entity *entity,
>>>> void *owner);
>>>> void drm_sched_job_arm(struct drm_sched_job *job);
>>>> +int drm_sched_job_await_fence(struct drm_sched_job *job,
>>>> + struct dma_fence *fence);
>>>> +int drm_sched_job_await_implicit(struct drm_sched_job *job,
>>>> + struct drm_gem_object *obj,
>>>> + bool write);
>>>> +
>>>> +
>>> I'm still waiting on the paint delivery for these two functions so I
>>> can finish this shed.
>> Well I wouldn't call that bike shedding, good names are important.
>>
>> Just imaging we would have called the exclusive-fence write-fence instead.
> Sure naming matters, but at least to my English understanding there's
> not a semantic different between telling something to await for
> something else (i.e. add a dependency) or to tell something to add a
> dependency (i.e. await that thing later on before you start doing your
> own thing).
To be honest I had to google what await means when you first mentioned
it because I didn't had that in my English vocabulary.
(But I have to note that my English education is basically non-existent.
I speak German and a good bunch of Dutch and just interfere most of the
words).
Regards,
Christian.
> Exclusive vs write fence otoh is a pretty big difference in what it means.
>
> But also if there's consensus that I'm wrong then I'm happy to pick
> the more preferred of the two options I deem equivalent.
>
>> What speaks against calling them add_dependency() and
>> _add_implicit_depencencies() ?
> Nothing. I just like another ack on this before I rename it all. Also
> I wasnt sure what you'd want to name the implicit dependency thing.
>
> Lucas, Boris, Melissa, any acks here?
> -Daniel
>
>> Regards,
>> Christian.
>>
>>> Thanks, Daniel
>>>
>>>> void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
>>>> struct drm_gpu_scheduler **sched_list,
>>>> unsigned int num_sched_list);
>>>> --
>>>> 2.32.0
>>>>
>
On 07/28, Daniel Vetter wrote:
> On Wed, Jul 28, 2021 at 1:29 PM Christian König
> <ckoenig.leichtzumerken@gmail.com> wrote:
> > Am 27.07.21 um 13:09 schrieb Daniel Vetter:
> > > Adding a few more people to this bikeshed.
> > >
> > > On Mon, Jul 12, 2021 at 10:02 PM Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> > >
> > >> @@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job,
> > >> struct drm_sched_entity *entity,
> > >> void *owner);
> > >> void drm_sched_job_arm(struct drm_sched_job *job);
> > >> +int drm_sched_job_await_fence(struct drm_sched_job *job,
> > >> + struct dma_fence *fence);
> > >> +int drm_sched_job_await_implicit(struct drm_sched_job *job,
> > >> + struct drm_gem_object *obj,
> > >> + bool write);
> > >> +
> > >> +
> > > I'm still waiting on the paint delivery for these two functions so I
> > > can finish this shed.
> >
> > Well I wouldn't call that bike shedding, good names are important.
> >
> > Just imaging we would have called the exclusive-fence write-fence instead.
>
> Sure naming matters, but at least to my English understanding there's
> not a semantic different between telling something to await for
> something else (i.e. add a dependency) or to tell something to add a
> dependency (i.e. await that thing later on before you start doing your
> own thing).
>
> Exclusive vs write fence otoh is a pretty big difference in what it means.
>
> But also if there's consensus that I'm wrong then I'm happy to pick
> the more preferred of the two options I deem equivalent.
>
> > What speaks against calling them add_dependency() and
> > _add_implicit_depencencies() ?
>
> Nothing. I just like another ack on this before I rename it all. Also
> I wasnt sure what you'd want to name the implicit dependency thing.
>
> Lucas, Boris, Melissa, any acks here?
so, my English is far from good; but _add_dependency sounds good to me.
Melissa
> -Daniel
>
> > Regards,
> > Christian.
> >
> > >
> > > Thanks, Daniel
> > >
> > >> void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
> > >> struct drm_gpu_scheduler **sched_list,
> > >> unsigned int num_sched_list);
> > >> --
> > >> 2.32.0
> > >>
> > >
> >
>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
@@ -211,6 +211,19 @@ static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
job->sched->ops->free_job(job);
}
+static struct dma_fence *
+drm_sched_job_dependency(struct drm_sched_job *job,
+ struct drm_sched_entity *entity)
+{
+ if (!xa_empty(&job->dependencies))
+ return xa_erase(&job->dependencies, job->last_dependency++);
+
+ if (job->sched->ops->dependency)
+ return job->sched->ops->dependency(job, entity);
+
+ return NULL;
+}
+
/**
* drm_sched_entity_kill_jobs - Make sure all remaining jobs are killed
*
@@ -229,7 +242,7 @@ static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
struct drm_sched_fence *s_fence = job->s_fence;
/* Wait for all dependencies to avoid data corruptions */
- while ((f = job->sched->ops->dependency(job, entity)))
+ while ((f = drm_sched_job_dependency(job, entity)))
dma_fence_wait(f, false);
drm_sched_fence_scheduled(s_fence);
@@ -419,7 +432,6 @@ static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
*/
struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
{
- struct drm_gpu_scheduler *sched = entity->rq->sched;
struct drm_sched_job *sched_job;
sched_job = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
@@ -427,7 +439,7 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
return NULL;
while ((entity->dependency =
- sched->ops->dependency(sched_job, entity))) {
+ drm_sched_job_dependency(sched_job, entity))) {
trace_drm_sched_job_wait_dep(sched_job, entity->dependency);
if (drm_sched_entity_add_dependency_cb(entity))
@@ -603,6 +603,8 @@ int drm_sched_job_init(struct drm_sched_job *job,
INIT_LIST_HEAD(&job->list);
+ xa_init_flags(&job->dependencies, XA_FLAGS_ALLOC);
+
return 0;
}
EXPORT_SYMBOL(drm_sched_job_init);
@@ -637,6 +639,98 @@ void drm_sched_job_arm(struct drm_sched_job *job)
}
EXPORT_SYMBOL(drm_sched_job_arm);
+/**
+ * drm_sched_job_await_fence - adds the fence as a job dependency
+ * @job: scheduler job to add the dependencies to
+ * @fence: the dma_fence to add to the list of dependencies.
+ *
+ * Note that @fence is consumed in both the success and error cases.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_await_fence(struct drm_sched_job *job,
+ struct dma_fence *fence)
+{
+ struct dma_fence *entry;
+ unsigned long index;
+ u32 id = 0;
+ int ret;
+
+ if (!fence)
+ return 0;
+
+ /* Deduplicate if we already depend on a fence from the same context.
+ * This lets the size of the array of deps scale with the number of
+ * engines involved, rather than the number of BOs.
+ */
+ xa_for_each(&job->dependencies, index, entry) {
+ if (entry->context != fence->context)
+ continue;
+
+ if (dma_fence_is_later(fence, entry)) {
+ dma_fence_put(entry);
+ xa_store(&job->dependencies, index, fence, GFP_KERNEL);
+ } else {
+ dma_fence_put(fence);
+ }
+ return 0;
+ }
+
+ ret = xa_alloc(&job->dependencies, &id, fence, xa_limit_32b, GFP_KERNEL);
+ if (ret != 0)
+ dma_fence_put(fence);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_sched_job_await_fence);
+
+/**
+ * drm_sched_job_await_implicit - adds implicit dependencies as job dependencies
+ * @job: scheduler job to add the dependencies to
+ * @obj: the gem object to add new dependencies from.
+ * @write: whether the job might write the object (so we need to depend on
+ * shared fences in the reservation object).
+ *
+ * This should be called after drm_gem_lock_reservations() on your array of
+ * GEM objects used in the job but before updating the reservations with your
+ * own fences.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_await_implicit(struct drm_sched_job *job,
+ struct drm_gem_object *obj,
+ bool write)
+{
+ int ret;
+ struct dma_fence **fences;
+ unsigned int i, fence_count;
+
+ if (!write) {
+ struct dma_fence *fence = dma_resv_get_excl_unlocked(obj->resv);
+
+ return drm_sched_job_await_fence(job, fence);
+ }
+
+ ret = dma_resv_get_fences(obj->resv, NULL, &fence_count, &fences);
+ if (ret || !fence_count)
+ return ret;
+
+ for (i = 0; i < fence_count; i++) {
+ ret = drm_sched_job_await_fence(job, fences[i]);
+ if (ret)
+ break;
+ }
+
+ for (; i < fence_count; i++)
+ dma_fence_put(fences[i]);
+ kfree(fences);
+ return ret;
+}
+EXPORT_SYMBOL(drm_sched_job_await_implicit);
+
+
/**
* drm_sched_job_cleanup - clean up scheduler job resources
* @job: scheduler job to clean up
@@ -652,6 +746,9 @@ EXPORT_SYMBOL(drm_sched_job_arm);
*/
void drm_sched_job_cleanup(struct drm_sched_job *job)
{
+ struct dma_fence *fence;
+ unsigned long index;
+
if (kref_read(&job->s_fence->finished.refcount)) {
/* drm_sched_job_arm() has been called */
dma_fence_put(&job->s_fence->finished);
@@ -661,6 +758,12 @@ void drm_sched_job_cleanup(struct drm_sched_job *job)
}
job->s_fence = NULL;
+
+ xa_for_each(&job->dependencies, index, fence) {
+ dma_fence_put(fence);
+ }
+ xa_destroy(&job->dependencies);
+
}
EXPORT_SYMBOL(drm_sched_job_cleanup);
@@ -27,9 +27,12 @@
#include <drm/spsc_queue.h>
#include <linux/dma-fence.h>
#include <linux/completion.h>
+#include <linux/xarray.h>
#define MAX_WAIT_SCHED_ENTITY_Q_EMPTY msecs_to_jiffies(1000)
+struct drm_gem_object;
+
struct drm_gpu_scheduler;
struct drm_sched_rq;
@@ -198,6 +201,16 @@ struct drm_sched_job {
enum drm_sched_priority s_priority;
struct drm_sched_entity *entity;
struct dma_fence_cb cb;
+ /**
+ * @dependencies:
+ *
+ * Contains the dependencies as struct dma_fence for this job, see
+ * drm_sched_job_await_fence() and drm_sched_job_await_implicit().
+ */
+ struct xarray dependencies;
+
+ /** @last_dependency: tracks @dependencies as they signal */
+ unsigned long last_dependency;
};
static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
@@ -220,9 +233,14 @@ enum drm_gpu_sched_stat {
*/
struct drm_sched_backend_ops {
/**
- * @dependency: Called when the scheduler is considering scheduling
- * this job next, to get another struct dma_fence for this job to
- * block on. Once it returns NULL, run_job() may be called.
+ * @dependency:
+ *
+ * Called when the scheduler is considering scheduling this job next, to
+ * get another struct dma_fence for this job to block on. Once it
+ * returns NULL, run_job() may be called.
+ *
+ * If a driver exclusively uses drm_sched_job_await_fence() and
+ * drm_sched_job_await_implicit() this can be ommitted and left as NULL.
*/
struct dma_fence *(*dependency)(struct drm_sched_job *sched_job,
struct drm_sched_entity *s_entity);
@@ -349,6 +367,13 @@ int drm_sched_job_init(struct drm_sched_job *job,
struct drm_sched_entity *entity,
void *owner);
void drm_sched_job_arm(struct drm_sched_job *job);
+int drm_sched_job_await_fence(struct drm_sched_job *job,
+ struct dma_fence *fence);
+int drm_sched_job_await_implicit(struct drm_sched_job *job,
+ struct drm_gem_object *obj,
+ bool write);
+
+
void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
struct drm_gpu_scheduler **sched_list,
unsigned int num_sched_list);