From patchwork Tue Sep 12 02:16:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Brost X-Patchwork-Id: 13380514 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 34E74CA0EC8 for ; Tue, 12 Sep 2023 02:17:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AA68B10E269; Tue, 12 Sep 2023 02:17:20 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3B65D10E20C; Tue, 12 Sep 2023 02:17:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694485039; x=1726021039; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=oON80VoDd92s1GQDTiALw3PKRcAbWAoN0A2/d2Ut4CI=; b=JAi8DhOgK21UaYcxr/RY5bolw2rOLyQKubSs/CxshPCIR6qLB9ggZDDA vgNtx6piy2wCXuL2QgPE2VedfjbAl4/1wLp7o/uhSWP98MsbbKWDnXJVw VdKvpQCOsQ0Feyca6RwjtJRd6z2wTfKFhm6/x3z+hBCEoUz+U3uZ0jvDD mFi4XzX/sZlxlTfu/xFhxo8SxBUCUI3fU1KXwHCEjBKroDC9u2iNJrlqX pQOo7bmn1joh/59PFLKk0MEcvNqMV5JePRAykPkYUVpjLC1B47m4S8roA JF3bJAa9NGUUZyaBFIdutOcvu4zH9GLnOVio4czDvpKoZ9nOfme70MIOL A==; X-IronPort-AV: E=McAfee;i="6600,9927,10830"; a="377172515" X-IronPort-AV: E=Sophos;i="6.02,244,1688454000"; d="scan'208";a="377172515" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2023 19:16:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10830"; a="917255559" X-IronPort-AV: E=Sophos;i="6.02,244,1688454000"; d="scan'208";a="917255559" Received: from lstrano-desk.jf.intel.com ([10.54.39.91]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2023 19:16:03 -0700 From: Matthew Brost To: dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org Subject: [PATCH v3 02/13] drm/sched: Convert drm scheduler to use a work queue rather than kthread Date: Mon, 11 Sep 2023 19:16:04 -0700 Message-Id: <20230912021615.2086698-3-matthew.brost@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230912021615.2086698-1-matthew.brost@intel.com> References: <20230912021615.2086698-1-matthew.brost@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robdclark@chromium.org, thomas.hellstrom@linux.intel.com, Matthew Brost , sarah.walker@imgtec.com, ketil.johnsen@arm.com, mcanal@igalia.com, Liviu.Dudau@arm.com, luben.tuikov@amd.com, lina@asahilina.net, donald.robson@imgtec.com, boris.brezillon@collabora.com, christian.koenig@amd.com, faith.ekstrand@collabora.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" In XE, the new Intel GPU driver, a choice has made to have a 1 to 1 mapping between a drm_gpu_scheduler and drm_sched_entity. At first this seems a bit odd but let us explain the reasoning below. 1. In XE the submission order from multiple drm_sched_entity is not guaranteed to be the same completion even if targeting the same hardware engine. This is because in XE we have a firmware scheduler, the GuC, which allowed to reorder, timeslice, and preempt submissions. If a using shared drm_gpu_scheduler across multiple drm_sched_entity, the TDR falls apart as the TDR expects submission order == completion order. Using a dedicated drm_gpu_scheduler per drm_sched_entity solve this problem. 2. In XE submissions are done via programming a ring buffer (circular buffer), a drm_gpu_scheduler provides a limit on number of jobs, if the limit of number jobs is set to RING_SIZE / MAX_SIZE_PER_JOB we get flow control on the ring for free. A problem with this design is currently a drm_gpu_scheduler uses a kthread for submission / job cleanup. This doesn't scale if a large number of drm_gpu_scheduler are used. To work around the scaling issue, use a worker rather than kthread for submission / job cleanup. v2: - (Rob Clark) Fix msm build - Pass in run work queue v3: - (Boris) don't have loop in worker v4: - (Tvrtko) break out submit ready, stop, start helpers into own patch Signed-off-by: Matthew Brost --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +- drivers/gpu/drm/etnaviv/etnaviv_sched.c | 2 +- drivers/gpu/drm/lima/lima_sched.c | 2 +- drivers/gpu/drm/msm/msm_ringbuffer.c | 2 +- drivers/gpu/drm/nouveau/nouveau_sched.c | 2 +- drivers/gpu/drm/panfrost/panfrost_job.c | 2 +- drivers/gpu/drm/scheduler/sched_main.c | 106 +++++++++------------ drivers/gpu/drm/v3d/v3d_sched.c | 10 +- include/drm/gpu_scheduler.h | 12 ++- 9 files changed, 65 insertions(+), 75 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 1f8a794704d0..c83a76bccc1d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -2305,7 +2305,7 @@ static int amdgpu_device_init_schedulers(struct amdgpu_device *adev) break; } - r = drm_sched_init(&ring->sched, &amdgpu_sched_ops, + r = drm_sched_init(&ring->sched, &amdgpu_sched_ops, NULL, ring->num_hw_submission, 0, timeout, adev->reset_domain->wq, ring->sched_score, ring->name, diff --git a/drivers/gpu/drm/etnaviv/etnaviv_sched.c b/drivers/gpu/drm/etnaviv/etnaviv_sched.c index 345fec6cb1a4..618a804ddc34 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_sched.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_sched.c @@ -134,7 +134,7 @@ int etnaviv_sched_init(struct etnaviv_gpu *gpu) { int ret; - ret = drm_sched_init(&gpu->sched, &etnaviv_sched_ops, + ret = drm_sched_init(&gpu->sched, &etnaviv_sched_ops, NULL, etnaviv_hw_jobs_limit, etnaviv_job_hang_limit, msecs_to_jiffies(500), NULL, NULL, dev_name(gpu->dev), gpu->dev); diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c index ffd91a5ee299..8d858aed0e56 100644 --- a/drivers/gpu/drm/lima/lima_sched.c +++ b/drivers/gpu/drm/lima/lima_sched.c @@ -488,7 +488,7 @@ int lima_sched_pipe_init(struct lima_sched_pipe *pipe, const char *name) INIT_WORK(&pipe->recover_work, lima_sched_recover_work); - return drm_sched_init(&pipe->base, &lima_sched_ops, 1, + return drm_sched_init(&pipe->base, &lima_sched_ops, NULL, 1, lima_job_hang_limit, msecs_to_jiffies(timeout), NULL, NULL, name, pipe->ldev->dev); diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c index 40c0bc35a44c..b8865e61b40f 100644 --- a/drivers/gpu/drm/msm/msm_ringbuffer.c +++ b/drivers/gpu/drm/msm/msm_ringbuffer.c @@ -94,7 +94,7 @@ struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int id, /* currently managing hangcheck ourselves: */ sched_timeout = MAX_SCHEDULE_TIMEOUT; - ret = drm_sched_init(&ring->sched, &msm_sched_ops, + ret = drm_sched_init(&ring->sched, &msm_sched_ops, NULL, num_hw_submissions, 0, sched_timeout, NULL, NULL, to_msm_bo(ring->bo)->name, gpu->dev->dev); if (ret) { diff --git a/drivers/gpu/drm/nouveau/nouveau_sched.c b/drivers/gpu/drm/nouveau/nouveau_sched.c index 88217185e0f3..d458c2227d4f 100644 --- a/drivers/gpu/drm/nouveau/nouveau_sched.c +++ b/drivers/gpu/drm/nouveau/nouveau_sched.c @@ -429,7 +429,7 @@ int nouveau_sched_init(struct nouveau_drm *drm) if (!drm->sched_wq) return -ENOMEM; - return drm_sched_init(sched, &nouveau_sched_ops, + return drm_sched_init(sched, &nouveau_sched_ops, NULL, NOUVEAU_SCHED_HW_SUBMISSIONS, 0, job_hang_limit, NULL, NULL, "nouveau_sched", drm->dev->dev); } diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 033f5e684707..326ca1ddf1d7 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -831,7 +831,7 @@ int panfrost_job_init(struct panfrost_device *pfdev) js->queue[j].fence_context = dma_fence_context_alloc(1); ret = drm_sched_init(&js->queue[j].sched, - &panfrost_sched_ops, + &panfrost_sched_ops, NULL, nentries, 0, msecs_to_jiffies(JOB_TIMEOUT_MS), pfdev->reset.wq, diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index e4fa62abca41..614e8c97a622 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -48,7 +48,6 @@ * through the jobs entity pointer. */ -#include #include #include #include @@ -256,6 +255,16 @@ drm_sched_rq_select_entity_fifo(struct drm_sched_rq *rq) return rb ? rb_entry(rb, struct drm_sched_entity, rb_tree_node) : NULL; } +/** + * drm_sched_submit_queue - scheduler queue submission + * @sched: scheduler instance + */ +static void drm_sched_submit_queue(struct drm_gpu_scheduler *sched) +{ + if (!READ_ONCE(sched->pause_submit)) + queue_work(sched->submit_wq, &sched->work_submit); +} + /** * drm_sched_job_done - complete a job * @s_job: pointer to the job which is done @@ -275,7 +284,7 @@ static void drm_sched_job_done(struct drm_sched_job *s_job, int result) dma_fence_get(&s_fence->finished); drm_sched_fence_finished(s_fence, result); dma_fence_put(&s_fence->finished); - wake_up_interruptible(&sched->wake_up_worker); + drm_sched_submit_queue(sched); } /** @@ -868,7 +877,7 @@ static bool drm_sched_can_queue(struct drm_gpu_scheduler *sched) void drm_sched_wakeup_if_can_queue(struct drm_gpu_scheduler *sched) { if (drm_sched_can_queue(sched)) - wake_up_interruptible(&sched->wake_up_worker); + drm_sched_submit_queue(sched); } /** @@ -978,61 +987,42 @@ drm_sched_pick_best(struct drm_gpu_scheduler **sched_list, } EXPORT_SYMBOL(drm_sched_pick_best); -/** - * drm_sched_blocked - check if the scheduler is blocked - * - * @sched: scheduler instance - * - * Returns true if blocked, otherwise false. - */ -static bool drm_sched_blocked(struct drm_gpu_scheduler *sched) -{ - if (kthread_should_park()) { - kthread_parkme(); - return true; - } - - return false; -} - /** * drm_sched_main - main scheduler thread * * @param: scheduler instance - * - * Returns 0. */ -static int drm_sched_main(void *param) +static void drm_sched_main(struct work_struct *w) { - struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param; + struct drm_gpu_scheduler *sched = + container_of(w, struct drm_gpu_scheduler, work_submit); + struct drm_sched_entity *entity; + struct drm_sched_job *cleanup_job; int r; - sched_set_fifo_low(current); + if (READ_ONCE(sched->pause_submit)) + return; - while (!kthread_should_stop()) { - struct drm_sched_entity *entity = NULL; - struct drm_sched_fence *s_fence; - struct drm_sched_job *sched_job; - struct dma_fence *fence; - struct drm_sched_job *cleanup_job = NULL; + cleanup_job = drm_sched_get_cleanup_job(sched); + entity = drm_sched_select_entity(sched); - wait_event_interruptible(sched->wake_up_worker, - (cleanup_job = drm_sched_get_cleanup_job(sched)) || - (!drm_sched_blocked(sched) && - (entity = drm_sched_select_entity(sched))) || - kthread_should_stop()); + if (!entity && !cleanup_job) + return; /* No more work */ - if (cleanup_job) - sched->ops->free_job(cleanup_job); + if (cleanup_job) + sched->ops->free_job(cleanup_job); - if (!entity) - continue; + if (entity) { + struct dma_fence *fence; + struct drm_sched_fence *s_fence; + struct drm_sched_job *sched_job; sched_job = drm_sched_entity_pop_job(entity); - if (!sched_job) { complete_all(&entity->entity_idle); - continue; + if (!cleanup_job) + return; /* No more work */ + goto again; } s_fence = sched_job->s_fence; @@ -1063,7 +1053,9 @@ static int drm_sched_main(void *param) wake_up(&sched->job_scheduled); } - return 0; + +again: + drm_sched_submit_queue(sched); } /** @@ -1071,6 +1063,7 @@ static int drm_sched_main(void *param) * * @sched: scheduler instance * @ops: backend operations for this scheduler + * @submit_wq: workqueue to use for submission. If NULL, the system_wq is used * @hw_submission: number of hw submissions that can be in flight * @hang_limit: number of times to allow a job to hang before dropping it * @timeout: timeout value in jiffies for the scheduler @@ -1084,14 +1077,16 @@ static int drm_sched_main(void *param) */ int drm_sched_init(struct drm_gpu_scheduler *sched, const struct drm_sched_backend_ops *ops, + struct workqueue_struct *submit_wq, unsigned hw_submission, unsigned hang_limit, long timeout, struct workqueue_struct *timeout_wq, atomic_t *score, const char *name, struct device *dev) { - int i, ret; + int i; sched->ops = ops; sched->hw_submission_limit = hw_submission; sched->name = name; + sched->submit_wq = submit_wq ? : system_wq; sched->timeout = timeout; sched->timeout_wq = timeout_wq ? : system_wq; sched->hang_limit = hang_limit; @@ -1100,23 +1095,15 @@ int drm_sched_init(struct drm_gpu_scheduler *sched, 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->wake_up_worker); init_waitqueue_head(&sched->job_scheduled); INIT_LIST_HEAD(&sched->pending_list); spin_lock_init(&sched->job_list_lock); atomic_set(&sched->hw_rq_count, 0); INIT_DELAYED_WORK(&sched->work_tdr, drm_sched_job_timedout); + INIT_WORK(&sched->work_submit, drm_sched_main); atomic_set(&sched->_score, 0); atomic64_set(&sched->job_id_count, 0); - - /* Each scheduler will run on a seperate kernel thread */ - sched->thread = kthread_run(drm_sched_main, sched, sched->name); - if (IS_ERR(sched->thread)) { - ret = PTR_ERR(sched->thread); - sched->thread = NULL; - DRM_DEV_ERROR(sched->dev, "Failed to create scheduler for %s.\n", name); - return ret; - } + sched->pause_submit = false; sched->ready = true; return 0; @@ -1135,8 +1122,7 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched) struct drm_sched_entity *s_entity; int i; - if (sched->thread) - kthread_stop(sched->thread); + drm_sched_submit_stop(sched); for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) { struct drm_sched_rq *rq = &sched->sched_rq[i]; @@ -1216,7 +1202,7 @@ EXPORT_SYMBOL(drm_sched_increase_karma); */ bool drm_sched_submit_ready(struct drm_gpu_scheduler *sched) { - return !!sched->thread; + return sched->ready; } EXPORT_SYMBOL(drm_sched_submit_ready); @@ -1228,7 +1214,8 @@ EXPORT_SYMBOL(drm_sched_submit_ready); */ void drm_sched_submit_stop(struct drm_gpu_scheduler *sched) { - kthread_park(sched->thread); + WRITE_ONCE(sched->pause_submit, true); + cancel_work_sync(&sched->work_submit); } EXPORT_SYMBOL(drm_sched_submit_stop); @@ -1239,6 +1226,7 @@ EXPORT_SYMBOL(drm_sched_submit_stop); */ void drm_sched_submit_start(struct drm_gpu_scheduler *sched) { - kthread_unpark(sched->thread); + WRITE_ONCE(sched->pause_submit, false); + queue_work(sched->submit_wq, &sched->work_submit); } EXPORT_SYMBOL(drm_sched_submit_start); diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c index 06238e6d7f5c..38e092ea41e6 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -388,7 +388,7 @@ v3d_sched_init(struct v3d_dev *v3d) int ret; ret = drm_sched_init(&v3d->queue[V3D_BIN].sched, - &v3d_bin_sched_ops, + &v3d_bin_sched_ops, NULL, hw_jobs_limit, job_hang_limit, msecs_to_jiffies(hang_limit_ms), NULL, NULL, "v3d_bin", v3d->drm.dev); @@ -396,7 +396,7 @@ v3d_sched_init(struct v3d_dev *v3d) return ret; ret = drm_sched_init(&v3d->queue[V3D_RENDER].sched, - &v3d_render_sched_ops, + &v3d_render_sched_ops, NULL, hw_jobs_limit, job_hang_limit, msecs_to_jiffies(hang_limit_ms), NULL, NULL, "v3d_render", v3d->drm.dev); @@ -404,7 +404,7 @@ v3d_sched_init(struct v3d_dev *v3d) goto fail; ret = drm_sched_init(&v3d->queue[V3D_TFU].sched, - &v3d_tfu_sched_ops, + &v3d_tfu_sched_ops, NULL, hw_jobs_limit, job_hang_limit, msecs_to_jiffies(hang_limit_ms), NULL, NULL, "v3d_tfu", v3d->drm.dev); @@ -413,7 +413,7 @@ v3d_sched_init(struct v3d_dev *v3d) if (v3d_has_csd(v3d)) { ret = drm_sched_init(&v3d->queue[V3D_CSD].sched, - &v3d_csd_sched_ops, + &v3d_csd_sched_ops, NULL, hw_jobs_limit, job_hang_limit, msecs_to_jiffies(hang_limit_ms), NULL, NULL, "v3d_csd", v3d->drm.dev); @@ -421,7 +421,7 @@ v3d_sched_init(struct v3d_dev *v3d) goto fail; ret = drm_sched_init(&v3d->queue[V3D_CACHE_CLEAN].sched, - &v3d_cache_clean_sched_ops, + &v3d_cache_clean_sched_ops, NULL, hw_jobs_limit, job_hang_limit, msecs_to_jiffies(hang_limit_ms), NULL, NULL, "v3d_cache_clean", v3d->drm.dev); diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h index f12c5aea5294..278106e358a8 100644 --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -473,17 +473,16 @@ struct drm_sched_backend_ops { * @timeout: the time after which a job is removed from the scheduler. * @name: name of the ring for which this scheduler is being used. * @sched_rq: priority wise array of run queues. - * @wake_up_worker: the wait queue on which the scheduler sleeps until a job - * is ready to be scheduled. * @job_scheduled: once @drm_sched_entity_do_release is called the scheduler * waits on this wait queue until all the scheduled jobs are * finished. * @hw_rq_count: the number of jobs currently in the hardware queue. * @job_id_count: used to assign unique id to the each job. + * @submit_wq: workqueue used to queue @work_submit * @timeout_wq: workqueue used to queue @work_tdr + * @work_submit: schedules jobs and cleans up entities * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the * timeout interval is over. - * @thread: the kthread on which the scheduler which run. * @pending_list: the list of jobs which are currently in the job queue. * @job_list_lock: lock to protect the pending_list. * @hang_limit: once the hangs by a job crosses this limit then it is marked @@ -492,6 +491,7 @@ struct drm_sched_backend_ops { * @_score: score used when the driver doesn't provide one * @ready: marks if the underlying HW is ready to work * @free_guilty: A hit to time out handler to free the guilty job. + * @pause_submit: pause queuing of @work_submit on @submit_wq * @dev: system &struct device * * One scheduler is implemented for each hardware ring. @@ -502,13 +502,13 @@ struct drm_gpu_scheduler { long timeout; const char *name; struct drm_sched_rq sched_rq[DRM_SCHED_PRIORITY_COUNT]; - wait_queue_head_t wake_up_worker; wait_queue_head_t job_scheduled; atomic_t hw_rq_count; atomic64_t job_id_count; + struct workqueue_struct *submit_wq; struct workqueue_struct *timeout_wq; + struct work_struct work_submit; struct delayed_work work_tdr; - struct task_struct *thread; struct list_head pending_list; spinlock_t job_list_lock; int hang_limit; @@ -516,11 +516,13 @@ struct drm_gpu_scheduler { atomic_t _score; bool ready; bool free_guilty; + bool pause_submit; struct device *dev; }; int drm_sched_init(struct drm_gpu_scheduler *sched, const struct drm_sched_backend_ops *ops, + struct workqueue_struct *submit_wq, uint32_t hw_submission, unsigned hang_limit, long timeout, struct workqueue_struct *timeout_wq, atomic_t *score, const char *name, struct device *dev);