Re: [PATCH v3 6/7] drm/xe: Remove special casing for LR queues in submission

[Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>]

On Thu, Oct 16, 2025 at 01:48:25PM -0700, Matthew Brost wrote:
>Now that LR jobs are tracked by the DRM scheduler, there's no longer a
>need to special-case LR queues. This change removes all LR
>queue-specific handling, including dedicated TDR logic, reference
>counting schemes, and other related mechanisms.
>
>Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>---
> drivers/gpu/drm/xe/xe_guc_exec_queue_types.h |   2 -
> drivers/gpu/drm/xe/xe_guc_submit.c           | 129 +------------------
> 2 files changed, 7 insertions(+), 124 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h b/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h
>index a3b034e4b205..fd0915ed8eb1 100644
>--- a/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h
>+++ b/drivers/gpu/drm/xe/xe_guc_exec_queue_types.h
>@@ -33,8 +33,6 @@ struct xe_guc_exec_queue {
> 	 */
> #define MAX_STATIC_MSG_TYPE	3
> 	struct xe_sched_msg static_msgs[MAX_STATIC_MSG_TYPE];
>-	/** @lr_tdr: long running TDR worker */
>-	struct work_struct lr_tdr;
> 	/** @destroy_async: do final destroy async from this worker */
> 	struct work_struct destroy_async;
> 	/** @resume_time: time of last resume */
>diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
>index ab0f1a2d4871..bb1f2929441c 100644
>--- a/drivers/gpu/drm/xe/xe_guc_submit.c
>+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
>@@ -674,14 +674,6 @@ static void register_exec_queue(struct xe_exec_queue *q, int ctx_type)
> 		parallel_write(xe, map, wq_desc.wq_status, WQ_STATUS_ACTIVE);
> 	}
>
>-	/*
>-	 * We must keep a reference for LR engines if engine is registered with
>-	 * the GuC as jobs signal immediately and can't destroy an engine if the
>-	 * GuC has a reference to it.
>-	 */
>-	if (xe_exec_queue_is_lr(q))
>-		xe_exec_queue_get(q);
>-
> 	set_exec_queue_registered(q);
> 	trace_xe_exec_queue_register(q);
> 	if (xe_exec_queue_is_parallel(q))
>@@ -854,7 +846,7 @@ guc_exec_queue_run_job(struct drm_sched_job *drm_job)
> 	struct xe_sched_job *job = to_xe_sched_job(drm_job);
> 	struct xe_exec_queue *q = job->q;
> 	struct xe_guc *guc = exec_queue_to_guc(q);
>-	bool lr = xe_exec_queue_is_lr(q), killed_or_banned_or_wedged =
>+	bool killed_or_banned_or_wedged =
> 		exec_queue_killed_or_banned_or_wedged(q);
>
> 	xe_gt_assert(guc_to_gt(guc), !(exec_queue_destroyed(q) || exec_queue_pending_disable(q)) ||
>@@ -871,15 +863,6 @@ guc_exec_queue_run_job(struct drm_sched_job *drm_job)
> 		job->skip_emit = false;
> 	}
>
>-	/*
>-	 * We don't care about job-fence ordering in LR VMs because these fences
>-	 * are never exported; they are used solely to keep jobs on the pending
>-	 * list. Once a queue enters an error state, there's no need to track
>-	 * them.
>-	 */
>-	if (killed_or_banned_or_wedged && lr)
>-		xe_sched_job_set_error(job, -ECANCELED);
>-

Why this piece of code here is being removed?

> 	return job->fence;
> }
>
>@@ -923,8 +906,7 @@ static void disable_scheduling_deregister(struct xe_guc *guc,
> 		xe_gt_warn(q->gt, "Pending enable/disable failed to respond\n");
> 		xe_sched_submission_start(sched);
> 		xe_gt_reset_async(q->gt);
>-		if (!xe_exec_queue_is_lr(q))
>-			xe_sched_tdr_queue_imm(sched);
>+		xe_sched_tdr_queue_imm(sched);
> 		return;
> 	}
>
>@@ -950,10 +932,7 @@ static void xe_guc_exec_queue_trigger_cleanup(struct xe_exec_queue *q)
> 	/** to wakeup xe_wait_user_fence ioctl if exec queue is reset */
> 	wake_up_all(&xe->ufence_wq);
>
>-	if (xe_exec_queue_is_lr(q))
>-		queue_work(guc_to_gt(guc)->ordered_wq, &q->guc->lr_tdr);
>-	else
>-		xe_sched_tdr_queue_imm(&q->guc->sched);
>+	xe_sched_tdr_queue_imm(&q->guc->sched);
> }
>
> /**
>@@ -1009,78 +988,6 @@ static bool guc_submit_hint_wedged(struct xe_guc *guc)
> 	return true;
> }
>
>-static void xe_guc_exec_queue_lr_cleanup(struct work_struct *w)
>-{
>-	struct xe_guc_exec_queue *ge =
>-		container_of(w, struct xe_guc_exec_queue, lr_tdr);
>-	struct xe_exec_queue *q = ge->q;
>-	struct xe_guc *guc = exec_queue_to_guc(q);
>-	struct xe_gpu_scheduler *sched = &ge->sched;
>-	struct drm_sched_job *job;
>-	bool wedged = false;
>-
>-	xe_gt_assert(guc_to_gt(guc), xe_exec_queue_is_lr(q));
>-
>-	if (vf_recovery(guc))
>-		return;
>-
>-	trace_xe_exec_queue_lr_cleanup(q);

Remove the trace event as well in xe_trace.h?

Niranjana

>-
>-	if (!exec_queue_killed(q))
>-		wedged = guc_submit_hint_wedged(exec_queue_to_guc(q));
>-
>-	/* Kill the run_job / process_msg entry points */
>-	xe_sched_submission_stop(sched);
>-
>-	/*
>-	 * Engine state now mostly stable, disable scheduling / deregister if
>-	 * needed. This cleanup routine might be called multiple times, where
>-	 * the actual async engine deregister drops the final engine ref.
>-	 * Calling disable_scheduling_deregister will mark the engine as
>-	 * destroyed and fire off the CT requests to disable scheduling /
>-	 * deregister, which we only want to do once. We also don't want to mark
>-	 * the engine as pending_disable again as this may race with the
>-	 * xe_guc_deregister_done_handler() which treats it as an unexpected
>-	 * state.
>-	 */
>-	if (!wedged && exec_queue_registered(q) && !exec_queue_destroyed(q)) {
>-		struct xe_guc *guc = exec_queue_to_guc(q);
>-		int ret;
>-
>-		set_exec_queue_banned(q);
>-		disable_scheduling_deregister(guc, q);
>-
>-		/*
>-		 * Must wait for scheduling to be disabled before signalling
>-		 * any fences, if GT broken the GT reset code should signal us.
>-		 */
>-		ret = wait_event_timeout(guc->ct.wq,
>-					 !exec_queue_pending_disable(q) ||
>-					 xe_guc_read_stopped(guc) ||
>-					 vf_recovery(guc), HZ * 5);
>-		if (vf_recovery(guc))
>-			return;
>-
>-		if (!ret) {
>-			xe_gt_warn(q->gt, "Schedule disable failed to respond, guc_id=%d\n",
>-				   q->guc->id);
>-			xe_devcoredump(q, NULL, "Schedule disable failed to respond, guc_id=%d\n",
>-				       q->guc->id);
>-			xe_sched_submission_start(sched);
>-			xe_gt_reset_async(q->gt);
>-			return;
>-		}
>-	}
>-
>-	if (!exec_queue_killed(q) && !xe_lrc_ring_is_idle(q->lrc[0]))
>-		xe_devcoredump(q, NULL, "LR job cleanup, guc_id=%d", q->guc->id);
>-
>-	drm_sched_for_each_pending_job(job, &sched->base, NULL)
>-		xe_sched_job_set_error(to_xe_sched_job(job), -ECANCELED);
>-
>-	xe_sched_submission_start(sched);
>-}
>-
> #define ADJUST_FIVE_PERCENT(__t)	mul_u64_u32_div(__t, 105, 100)
>
> static bool check_timeout(struct xe_exec_queue *q, struct xe_sched_job *job)
>@@ -1150,8 +1057,7 @@ static void enable_scheduling(struct xe_exec_queue *q)
> 		xe_gt_warn(guc_to_gt(guc), "Schedule enable failed to respond");
> 		set_exec_queue_banned(q);
> 		xe_gt_reset_async(q->gt);
>-		if (!xe_exec_queue_is_lr(q))
>-			xe_sched_tdr_queue_imm(&q->guc->sched);
>+		xe_sched_tdr_queue_imm(&q->guc->sched);
> 	}
> }
>
>@@ -1189,8 +1095,6 @@ guc_exec_queue_timedout_job(struct drm_sched_job *drm_job)
> 	pid_t pid = -1;
> 	bool wedged = false, skip_timeout_check;
>
>-	xe_gt_assert(guc_to_gt(guc), !xe_exec_queue_is_lr(q));
>-
> 	/*
> 	 * TDR has fired before free job worker. Common if exec queue
> 	 * immediately closed after last fence signaled. Add back to pending
>@@ -1395,8 +1299,6 @@ static void __guc_exec_queue_destroy_async(struct work_struct *w)
> 	xe_pm_runtime_get(guc_to_xe(guc));
> 	trace_xe_exec_queue_destroy(q);
>
>-	if (xe_exec_queue_is_lr(q))
>-		cancel_work_sync(&ge->lr_tdr);
> 	/* Confirm no work left behind accessing device structures */
> 	cancel_delayed_work_sync(&ge->sched.base.work_tdr);
>
>@@ -1629,9 +1531,6 @@ static int guc_exec_queue_init(struct xe_exec_queue *q)
> 	if (err)
> 		goto err_sched;
>
>-	if (xe_exec_queue_is_lr(q))
>-		INIT_WORK(&q->guc->lr_tdr, xe_guc_exec_queue_lr_cleanup);
>-
> 	mutex_lock(&guc->submission_state.lock);
>
> 	err = alloc_guc_id(guc, q);
>@@ -1885,9 +1784,7 @@ static void guc_exec_queue_stop(struct xe_guc *guc, struct xe_exec_queue *q)
>
> 	/* Clean up lost G2H + reset engine state */
> 	if (exec_queue_registered(q)) {
>-		if (xe_exec_queue_is_lr(q))
>-			xe_exec_queue_put(q);
>-		else if (exec_queue_destroyed(q))
>+		if (exec_queue_destroyed(q))
> 			__guc_exec_queue_destroy(guc, q);
> 	}
> 	if (q->guc->suspend_pending) {
>@@ -1917,9 +1814,6 @@ static void guc_exec_queue_stop(struct xe_guc *guc, struct xe_exec_queue *q)
> 				trace_xe_sched_job_ban(job);
> 				ban = true;
> 			}
>-		} else if (xe_exec_queue_is_lr(q) &&
>-			   !xe_lrc_ring_is_idle(q->lrc[0])) {
>-			ban = true;
> 		}
>
> 		if (ban) {
>@@ -2002,8 +1896,6 @@ static void guc_exec_queue_revert_pending_state_change(struct xe_guc *guc,
> 	if (pending_enable && !pending_resume &&
> 	    !exec_queue_pending_tdr_exit(q)) {
> 		clear_exec_queue_registered(q);
>-		if (xe_exec_queue_is_lr(q))
>-			xe_exec_queue_put(q);
> 		xe_gt_dbg(guc_to_gt(guc), "Replay REGISTER - guc_id=%d",
> 			  q->guc->id);
> 	}
>@@ -2060,10 +1952,7 @@ static void guc_exec_queue_pause(struct xe_guc *guc, struct xe_exec_queue *q)
>
> 	/* Stop scheduling + flush any DRM scheduler operations */
> 	xe_sched_submission_stop(sched);
>-	if (xe_exec_queue_is_lr(q))
>-		cancel_work_sync(&q->guc->lr_tdr);
>-	else
>-		cancel_delayed_work_sync(&sched->base.work_tdr);
>+	cancel_delayed_work_sync(&sched->base.work_tdr);
>
> 	guc_exec_queue_revert_pending_state_change(guc, q);
>
>@@ -2435,11 +2324,7 @@ static void handle_deregister_done(struct xe_guc *guc, struct xe_exec_queue *q)
> 	trace_xe_exec_queue_deregister_done(q);
>
> 	clear_exec_queue_registered(q);
>-
>-	if (xe_exec_queue_is_lr(q))
>-		xe_exec_queue_put(q);
>-	else
>-		__guc_exec_queue_destroy(guc, q);
>+	__guc_exec_queue_destroy(guc, q);
> }
>
> int xe_guc_deregister_done_handler(struct xe_guc *guc, u32 *msg, u32 len)
>-- 
>2.34.1
>