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 9AFC83209 for ; Tue, 29 Jul 2025 16:16:43 +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=1753805804; cv=none; b=ZY0UrkpwhQwv5Y0s6x3K9sPCAr7G7FPc+0J2aPjqM8UOEDEsYocimSM73PZznEdmsHck3H+Mp+iWLPNU9PSwFP/g1UEWLqKqJ2gKVzudYO8jGhb970sHZ5n5Gf4pjr9WMiszx9vvE1kAQSChuiSIXiNIb4yt/GJVF3VhKQOnQu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753805804; c=relaxed/simple; bh=M8rOGbn29UpECiy8i7bH+pyhSx8+I9qWVUnXNDZYbD0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=uEZC5l+kT9i62gyUjV7JxVGNjy5La455kSvGS4TCX3ycZnAkOZVw7XNUPrrvXNKwpT+evnp6nnQbuBvQr/aUX/z034o9mF1GpNBDu1arVopaepFWv93+4Ko1XUsYx9kX78lACRZc7ztu1NjZdo1KHtFGwDztndwqxZnvdThwZPg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AuyOmfSK; 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="AuyOmfSK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34886C4CEEF; Tue, 29 Jul 2025 16:16:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753805803; bh=M8rOGbn29UpECiy8i7bH+pyhSx8+I9qWVUnXNDZYbD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AuyOmfSKNHBEiQyneJtFDKaZNH7hiM3vxnpSb7tWU3IdmX8YX0I8Q1q5+IK+3M+yz ayIGupDkqHbskWlo5oQsr/w5eEoApbNWCD/wVmrB7aQwsS794Ye072/ClC8XNEOjzA n5gVli7UpG6lEEiqwdYwfixKkvJyJayLHkUmE2w9MoRJmKvfFVKBMUdQLr94YlkwY5 PYpD6KrTPVWd0je0lZToeuvMOVOMWd5CD8ejGsLO1PmLkfCo55MG5gVB0YqJN65hSR lVDwqQDUcxy4bMSoNAiC362DzluhT494DJNQUgE6W7fpqfCZZYBQO//bUGeRjYX2lL RKI+cFpNYXp1w== From: Sasha Levin To: stable@vger.kernel.org Cc: "Lin.Cao" , =?UTF-8?q?Christian=20K=C3=B6nig?= , Philipp Stanner , Sasha Levin Subject: [PATCH 5.15.y] drm/sched: Remove optimization that causes hang when killing dependent jobs Date: Tue, 29 Jul 2025 12:16:38 -0400 Message-Id: <20250729161638.2745002-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <2025072854-backlog-freeness-4f50@gregkh> References: <2025072854-backlog-freeness-4f50@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 [ Changed drm_sched_wakeup_if_can_queue() calls to drm_sched_wakeup() ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/scheduler/sched_entity.c | 27 ++++-------------------- 1 file changed, 4 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 049d520226b1..9343b5a74c71 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -317,21 +317,8 @@ 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 + * drm_sched_entity_wakeup - callback to clear the entity's dependency and + * wake up the scheduler */ static void drm_sched_entity_wakeup(struct dma_fence *f, struct dma_fence_cb *cb) @@ -339,7 +326,8 @@ 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); } @@ -395,13 +383,6 @@ 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