Hi David, On Thu, Aug 2, 2018 at 8:22 AM Zhou, David(ChunMing) <David1.Zhou at amd.com> wrote: > Another big question: > > I agree the general idea is good to balance scheduler load for same ring > family. > > But, when same entity job run on different scheduler, that means the later > job could be completed ahead of front, Right? > Really good question. To avoid this senario we do not move an entity which already has a job in the hardware queue. We only move entities whose last_scheduled fence has been signalled which means that the last submitted job of this entity has finished executing. Moving an entity which already has a job in the hardware queue will hinder the dependency optimization that we are using and hence will not anyway lead to a better performance. I have talked about the issue in more detail here [1]. Please let me know if you have any more doubts regarding this. Cheers, Nayan [1] http://ndesh26.github.io/gsoc/2018/06/14/GSoC-Update-A-Curious-Case-of-Dependency-Handling/ That will break fence design, later fence must be signaled after front > fence in same fence context. > > > > Anything I missed? > > > > Regards, > > David Zhou > > > > *From:* dri-devel <dri-devel-bounces at lists.freedesktop.org> *On Behalf Of > *Nayan Deshmukh > *Sent:* Thursday, August 02, 2018 12:07 AM > *To:* Grodzovsky, Andrey <Andrey.Grodzovsky at amd.com> > *Cc:* amd-gfx at lists.freedesktop.org; Maling list - DRI developers < > dri-devel at lists.freedesktop.org>; Koenig, Christian < > Christian.Koenig at amd.com> > *Subject:* Re: [PATCH 3/4] drm/scheduler: add new function to get least > loaded sched v2 > > > > Yes, that is correct. > > > > Nayan > > > > On Wed, Aug 1, 2018, 9:05 PM Andrey Grodzovsky <Andrey.Grodzovsky at amd.com> > wrote: > > Clarification question - if the run queues belong to different > schedulers they effectively point to different rings, > > it means we allow to move (reschedule) a drm_sched_entity from one ring > to another - i assume that the idea int the first place, that > > you have a set of HW rings and you can utilize any of them for your jobs > (like compute rings). Correct ? > > Andrey > > > On 08/01/2018 04:20 AM, Nayan Deshmukh wrote: > > The function selects the run queue from the rq_list with the > > least load. The load is decided by the number of jobs in a > > scheduler. > > > > v2: avoid using atomic read twice consecutively, instead store > > it locally > > > > Signed-off-by: Nayan Deshmukh <nayan26deshmukh at gmail.com> > > --- > > drivers/gpu/drm/scheduler/gpu_scheduler.c | 25 > +++++++++++++++++++++++++ > > 1 file changed, 25 insertions(+) > > > > diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c > b/drivers/gpu/drm/scheduler/gpu_scheduler.c > > index 375f6f7f6a93..fb4e542660b0 100644 > > --- a/drivers/gpu/drm/scheduler/gpu_scheduler.c > > +++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c > > @@ -255,6 +255,31 @@ static bool drm_sched_entity_is_ready(struct > drm_sched_entity *entity) > > return true; > > } > > > > +/** > > + * drm_sched_entity_get_free_sched - Get the rq from rq_list with least > load > > + * > > + * @entity: scheduler entity > > + * > > + * Return the pointer to the rq with least load. > > + */ > > +static struct drm_sched_rq * > > +drm_sched_entity_get_free_sched(struct drm_sched_entity *entity) > > +{ > > + struct drm_sched_rq *rq = NULL; > > + unsigned int min_jobs = UINT_MAX, num_jobs; > > + int i; > > + > > + for (i = 0; i < entity->num_rq_list; ++i) { > > + num_jobs = > atomic_read(&entity->rq_list[i]->sched->num_jobs); > > + if (num_jobs < min_jobs) { > > + min_jobs = num_jobs; > > + rq = entity->rq_list[i]; > > + } > > + } > > + > > + return rq; > > +} > > + > > static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f, > > struct dma_fence_cb *cb) > > { > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20180802/3118bd0a/attachment.html>
