On Thu, Apr 5, 2018 at 2:16 AM, Daniel Vetter <dan...@ffwll.ch> wrote: > On Thu, Apr 5, 2018 at 12:32 AM, Eric Anholt <e...@anholt.net> wrote: >> These comments answer all the questions I had for myself when >> implementing a driver using the GPU scheduler. >> >> Signed-off-by: Eric Anholt <e...@anholt.net> > > Pulling all these comments into the generated kerneldoc would be > awesome, maybe as a new "GPU Scheduler" chapter at the end of > drm-mm.rst? Would mean a bit of busywork to convert the existing raw > comments into proper kerneldoc. Also has the benefit that 0day will > complain when you forget to update the comment when editing the > function prototype - kerneldoc which isn't included anywhere in .rst > won't be checked automatically.
I was actually planning to do this myself, but Nayan wanted to do this a prep work for his proposed GSoC project so I was going to see how far he got first. Alex > -Daniel > >> --- >> include/drm/gpu_scheduler.h | 46 +++++++++++++++++++++++++++++++++---- >> 1 file changed, 42 insertions(+), 4 deletions(-) >> >> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h >> index dfd54fb94e10..c053a32341bf 100644 >> --- a/include/drm/gpu_scheduler.h >> +++ b/include/drm/gpu_scheduler.h >> @@ -43,10 +43,12 @@ enum drm_sched_priority { >> }; >> >> /** >> - * A scheduler entity is a wrapper around a job queue or a group >> - * of other entities. Entities take turns emitting jobs from their >> - * job queues to corresponding hardware ring based on scheduling >> - * policy. >> + * drm_sched_entity - A wrapper around a job queue (typically attached >> + * to the DRM file_priv). >> + * >> + * Entities will emit jobs in order to their corresponding hardware >> + * ring, and the scheduler will alternate between entities based on >> + * scheduling policy. >> */ >> struct drm_sched_entity { >> struct list_head list; >> @@ -78,7 +80,18 @@ struct drm_sched_rq { >> >> struct drm_sched_fence { >> struct dma_fence scheduled; >> + >> + /* This fence is what will be signaled by the scheduler when >> + * the job is completed. >> + * >> + * When setting up an out fence for the job, you should use >> + * this, since it's available immediately upon >> + * drm_sched_job_init(), and the fence returned by the driver >> + * from run_job() won't be created until the dependencies have >> + * resolved. >> + */ >> struct dma_fence finished; >> + >> struct dma_fence_cb cb; >> struct dma_fence *parent; >> struct drm_gpu_scheduler *sched; >> @@ -88,6 +101,13 @@ struct drm_sched_fence { >> >> struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f); >> >> +/** >> + * drm_sched_job - A job to be run by an entity. >> + * >> + * A job is created by the driver using drm_sched_job_init(), and >> + * should call drm_sched_entity_push_job() once it wants the scheduler >> + * to schedule the job. >> + */ >> struct drm_sched_job { >> struct spsc_node queue_node; >> struct drm_gpu_scheduler *sched; >> @@ -112,10 +132,28 @@ static inline bool drm_sched_invalidate_job(struct >> drm_sched_job *s_job, >> * these functions should be implemented in driver side >> */ >> struct drm_sched_backend_ops { >> + /* 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. >> + */ >> struct dma_fence *(*dependency)(struct drm_sched_job *sched_job, >> struct drm_sched_entity *s_entity); >> + >> + /* Called to execute the job once all of the dependencies have >> + * been resolved. This may be called multiple times, if >> + * timedout_job() has happened and drm_sched_job_recovery() >> + * decides to try it again. >> + */ >> struct dma_fence *(*run_job)(struct drm_sched_job *sched_job); >> + >> + /* Called when a job has taken too long to execute, to trigger >> + * GPU recovery. >> + */ >> void (*timedout_job)(struct drm_sched_job *sched_job); >> + >> + /* Called once the job's finished fence has been signaled and >> + * it's time to clean it up. >> + */ >> void (*free_job)(struct drm_sched_job *sched_job); >> }; >> >> -- >> 2.17.0 >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/dri-devel > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel