From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B9E723FC41; Tue, 11 Nov 2025 00:57:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762822677; cv=none; b=lSwEFPXvSP84GS57WyfL1DGHnGkF8g4FcAhxu/0IeuYP1ANkoPH8g2PvFwntsaInPaKdM2+Ze1ICxjS0VtWyePDsjhGKW8lXFTRheqtpna9wLWwvUGNNoO7uw6sPguTkXoNJWYGStO3S9ynDFBx41pJezqm0GGAG4XdcAhqbgNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762822677; c=relaxed/simple; bh=S6LPenAJA445iFiwHvuS7U/rGBDVr/jYmV/KwBMTk4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ijuLoTwXajyLBpAHApfjbH8tP+j87KXvW+y9i012SQXn4hK4AQwCutu5jsrYu2LnQkXEmOe7GohuOP1V6Lh1MD9nxUyyxuqvQsWAiooibdLfnoAcmRIAkn4VAsDiQeqGUkTGC4VbTy3J71C39WGZAzOLVpmwthcnm0fTB6y9JIk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AhXBgzGR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AhXBgzGR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AC0EC116B1; Tue, 11 Nov 2025 00:57:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762822677; bh=S6LPenAJA445iFiwHvuS7U/rGBDVr/jYmV/KwBMTk4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AhXBgzGRKuojdA1GSGAsis6LdO1LA/IW35vDWJ/HZ/7wIavpuxEizMEKaQwz4iF5y 30A1DRYuQH8oqux9vWGHI2jQzpL5Dbxw7DS5HdZWp9oLeHEjIScS3m16fS7bVUzb+x dMt/zyT0thWnzpQxx40vuLlfs3sVmPtA1jbNpqxM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tvrtko Ursulin , =?UTF-8?q?Christian=20K=C3=B6nig?= , Alex Deucher , Luben Tuikov , Matthew Brost , Philipp Stanner , Sasha Levin Subject: [PATCH 6.12 084/565] drm/sched: Re-group and rename the entity run-queue lock Date: Tue, 11 Nov 2025 09:39:00 +0900 Message-ID: <20251111004528.857251276@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004526.816196597@linuxfoundation.org> References: <20251111004526.816196597@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tvrtko Ursulin [ Upstream commit f93126f5d55920d1447ef00a3fbe6706f40f53de ] When writing to a drm_sched_entity's run-queue, writers are protected through the lock drm_sched_entity.rq_lock. This naming, however, frequently collides with the separate internal lock of struct drm_sched_rq, resulting in uses like this: spin_lock(&entity->rq_lock); spin_lock(&entity->rq->lock); Rename drm_sched_entity.rq_lock to improve readability. While at it, re-order that struct's members to make it more obvious what the lock protects. v2: * Rename some rq_lock straddlers in kerneldoc, improve commit text. (Philipp) Signed-off-by: Tvrtko Ursulin Suggested-by: Christian König Cc: Alex Deucher Cc: Luben Tuikov Cc: Matthew Brost Cc: Philipp Stanner Reviewed-by: Christian König [pstanner: Fix typo in docstring] Signed-off-by: Philipp Stanner Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-5-tursulin@igalia.com Stable-dep-of: d25e3a610bae ("drm/sched: Fix race in drm_sched_entity_select_rq()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/scheduler/sched_entity.c | 28 ++++++++++++++-------------- drivers/gpu/drm/scheduler/sched_main.c | 2 +- include/drm/gpu_scheduler.h | 21 +++++++++++---------- 3 files changed, 26 insertions(+), 25 deletions(-) --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -106,7 +106,7 @@ int drm_sched_entity_init(struct drm_sch /* We start in an idle state. */ complete_all(&entity->entity_idle); - spin_lock_init(&entity->rq_lock); + spin_lock_init(&entity->lock); spsc_queue_init(&entity->job_queue); atomic_set(&entity->fence_seq, 0); @@ -134,10 +134,10 @@ void drm_sched_entity_modify_sched(struc { WARN_ON(!num_sched_list || !sched_list); - spin_lock(&entity->rq_lock); + spin_lock(&entity->lock); entity->sched_list = sched_list; entity->num_sched_list = num_sched_list; - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); } EXPORT_SYMBOL(drm_sched_entity_modify_sched); @@ -246,10 +246,10 @@ static void drm_sched_entity_kill(struct if (!entity->rq) return; - spin_lock(&entity->rq_lock); + spin_lock(&entity->lock); entity->stopped = true; drm_sched_rq_remove_entity(entity->rq, entity); - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); /* Make sure this entity is not used by the scheduler at the moment */ wait_for_completion(&entity->entity_idle); @@ -395,9 +395,9 @@ static void drm_sched_entity_wakeup(stru void drm_sched_entity_set_priority(struct drm_sched_entity *entity, enum drm_sched_priority priority) { - spin_lock(&entity->rq_lock); + spin_lock(&entity->lock); entity->priority = priority; - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); } EXPORT_SYMBOL(drm_sched_entity_set_priority); @@ -507,10 +507,10 @@ struct drm_sched_job *drm_sched_entity_p next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue)); if (next) { - spin_lock(&entity->rq_lock); + spin_lock(&entity->lock); drm_sched_rq_update_fifo_locked(entity, next->submit_ts); - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); } } @@ -551,14 +551,14 @@ void drm_sched_entity_select_rq(struct d if (fence && !dma_fence_is_signaled(fence)) return; - spin_lock(&entity->rq_lock); + spin_lock(&entity->lock); sched = drm_sched_pick_best(entity->sched_list, entity->num_sched_list); rq = sched ? sched->sched_rq[entity->priority] : NULL; if (rq != entity->rq) { drm_sched_rq_remove_entity(entity->rq, entity); entity->rq = rq; } - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); if (entity->num_sched_list == 1) entity->sched_list = NULL; @@ -599,9 +599,9 @@ void drm_sched_entity_push_job(struct dr struct drm_sched_rq *rq; /* Add the entity to the run queue */ - spin_lock(&entity->rq_lock); + spin_lock(&entity->lock); if (entity->stopped) { - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); DRM_ERROR("Trying to push to a killed entity\n"); return; @@ -615,7 +615,7 @@ void drm_sched_entity_push_job(struct dr if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) drm_sched_rq_update_fifo_locked(entity, submit_ts); - spin_unlock(&entity->rq_lock); + spin_unlock(&entity->lock); drm_sched_wakeup(sched); } --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -176,7 +176,7 @@ void drm_sched_rq_update_fifo_locked(str * for entity from within concurrent drm_sched_entity_select_rq and the * other to update the rb tree structure. */ - lockdep_assert_held(&entity->rq_lock); + lockdep_assert_held(&entity->lock); spin_lock(&entity->rq->lock); --- a/include/drm/gpu_scheduler.h +++ b/include/drm/gpu_scheduler.h @@ -97,13 +97,21 @@ struct drm_sched_entity { struct list_head list; /** + * @lock: + * + * Lock protecting the run-queue (@rq) to which this entity belongs, + * @priority and the list of schedulers (@sched_list, @num_sched_list). + */ + spinlock_t lock; + + /** * @rq: * * Runqueue on which this entity is currently scheduled. * * FIXME: Locking is very unclear for this. Writers are protected by - * @rq_lock, but readers are generally lockless and seem to just race - * with not even a READ_ONCE. + * @lock, but readers are generally lockless and seem to just race with + * not even a READ_ONCE. */ struct drm_sched_rq *rq; @@ -136,18 +144,11 @@ struct drm_sched_entity { * @priority: * * Priority of the entity. This can be modified by calling - * drm_sched_entity_set_priority(). Protected by &rq_lock. + * drm_sched_entity_set_priority(). Protected by @lock. */ enum drm_sched_priority priority; /** - * @rq_lock: - * - * Lock to modify the runqueue to which this entity belongs. - */ - spinlock_t rq_lock; - - /** * @job_queue: the list of jobs of this entity. */ struct spsc_queue job_queue;