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 4815A298CC3 for ; Tue, 29 Jul 2025 17:15:01 +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=1753809302; cv=none; b=gUZuIy36oCbStNcYv0CgL5fbsJn/Z5cGt5nWZZYW93dGmWxWbqrfzg8kKSt2PNtMtaIE3NBk/wP1eRoUze4uFcEtXEpo+v4Ex/2dMVN+4/lnAYxZ6LDBtFVIBoGETmgjEzoT0CALZL92V+Zm+wL5A3W0fwRBVxwR272uyGqFy9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753809302; c=relaxed/simple; bh=cR9COhT2vhCFWAePg4zLviWdsd9iTTa49HVQiRvQoqA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=OAJEroyhUiKP2fTNcB5myS3Mo74v3l9+ZTBtXjn6FOhfDbHFO3Qu40xwWIfd/CpyYB+lkGZU00xA0eQEPeAxr7fMp8thsOt/1GD6OBuWEgiRf//Lz5j6iCdILuWnY0AhPrzUqpedN5Pa7K3JJ8PqA40qRVBrNKx+9sahTsd8+L8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FB9FsVeh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FB9FsVeh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D32EC4CEF4; Tue, 29 Jul 2025 17:15:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753809301; bh=cR9COhT2vhCFWAePg4zLviWdsd9iTTa49HVQiRvQoqA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FB9FsVehMXpo/mVwazP+MlBExVTS77LNu4vIfnNAgUZD9UA22IsVW195ngVkZALg2 PhfKx9TdlEgcO+lsD9zgii3rBRwP3ckMSMVWsyMfY8CMp+avLel3GtZ8XJMAzsTd9R mA6TbkVCzvblfBbLwiEeqYne9B+HMAxkM03BjV5W/cb21GGHfEL3QgklmN2uUeK5x9 SNDTZ78tOp3TAEjMH4rGgKfbApM5XmEwpyBJEpQFrpxNfbTWmTLC5DbYdHpKfRqI0X IH6tR20ZRWLEMrSneZPR08G8/KWVHoUJb3L3pOH6OXrwxAy2KF6s6ViNqTwOEnn9dX +qW4T1vaup4wQ== From: Sasha Levin To: stable@vger.kernel.org Cc: "Lin.Cao" , =?UTF-8?q?Christian=20K=C3=B6nig?= , Philipp Stanner , Sasha Levin Subject: [PATCH 5.4.y] drm/sched: Remove optimization that causes hang when killing dependent jobs Date: Tue, 29 Jul 2025 13:14:55 -0400 Message-Id: <20250729171455.2825719-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <2025072855-spongy-yodel-58e6@gregkh> References: <2025072855-spongy-yodel-58e6@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: "Lin.Cao" [ Upstream commit 15f77764e90a713ee3916ca424757688e4f565b9 ] When application A submits jobs and application B submits a job with a dependency on A's fence, the normal flow wakes up the scheduler after processing each job. However, the optimization in drm_sched_entity_add_dependency_cb() uses a callback that only clears dependencies without waking up the scheduler. When application A is killed before its jobs can run, the callback gets triggered but only clears the dependency without waking up the scheduler, causing the scheduler to enter sleep state and application B to hang. Remove the optimization by deleting drm_sched_entity_clear_dep() and its usage, ensuring the scheduler is always woken up when dependencies are cleared. Fixes: 777dbd458c89 ("drm/amdgpu: drop a dummy wakeup scheduler") Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Lin.Cao Reviewed-by: Christian König Signed-off-by: Philipp Stanner Link: https://lore.kernel.org/r/20250717084453.921097-1-lincao12@amd.com [ adjusted context ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/scheduler/sched_entity.c | 23 ++--------------------- 1 file changed, 2 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 57f9baad9e36..d9b20bb7c7f5 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -327,19 +327,6 @@ void drm_sched_entity_destroy(struct drm_sched_entity *entity) } EXPORT_SYMBOL(drm_sched_entity_destroy); -/** - * drm_sched_entity_clear_dep - callback to clear the entities dependency - */ -static void drm_sched_entity_clear_dep(struct dma_fence *f, - struct dma_fence_cb *cb) -{ - struct drm_sched_entity *entity = - container_of(cb, struct drm_sched_entity, cb); - - entity->dependency = NULL; - dma_fence_put(f); -} - /** * drm_sched_entity_clear_dep - callback to clear the entities dependency and * wake up scheduler @@ -350,7 +337,8 @@ static void drm_sched_entity_wakeup(struct dma_fence *f, struct drm_sched_entity *entity = container_of(cb, struct drm_sched_entity, cb); - drm_sched_entity_clear_dep(f, cb); + entity->dependency = NULL; + dma_fence_put(f); drm_sched_wakeup(entity->rq->sched); } @@ -426,13 +414,6 @@ static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity) fence = dma_fence_get(&s_fence->scheduled); dma_fence_put(entity->dependency); entity->dependency = fence; - if (!dma_fence_add_callback(fence, &entity->cb, - drm_sched_entity_clear_dep)) - return true; - - /* Ignore it when it is already scheduled */ - dma_fence_put(fence); - return false; } if (!dma_fence_add_callback(entity->dependency, &entity->cb, -- 2.39.5