From mboxrd@z Thu Jan 1 00:00:00 1970 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 4DA66C79F9F for ; Thu, 10 Sep 2026 08:00:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6253110F353; Thu, 10 Sep 2026 08:00:22 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="ZuOJwkwt"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0227E10F353 for ; Thu, 10 Sep 2026 08:00:21 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 7AD4760216; Thu, 10 Sep 2026 08:00:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95A731F000FF; Thu, 10 Sep 2026 08:00:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789027220; bh=hdqZMf+Q3fCD1KfNYFni9UVbypZbZ+uQ54oqG5U6q0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZuOJwkwtd0qQW5pYo/dNkTIcXlgqCpRDYdc53tWdkiDOvRVSrJv9y4h6I4x2SXLRR NXosFSngbQEtSzPY9M8u7L1thsIBucnGPkdCsGW/pjGaSvD/M7LX1tsGp/Icwbn3T+ nDwb1ra877GdvjlxIRM2mzG9w5GX1YdctgodwyL5FQM4Vjl2sq7poF4lTFsqLEDdfF shbGov40PL3byTTjLXvoGI0/5TmOWuaNf5uOP7Uc/4UXkWneIgbfvhhmpUXR1PdVbx RewTVhvoxlejjVueYr5jstxpNgGc+JNGLKpo5Fq+2UX9YHANGXhkDsWOAELOVpjuKT Ort/MA8mc1qOA== From: Philipp Stanner To: Danilo Krummrich , Philipp Stanner , =?UTF-8?q?Christian=20K=C3=B6nig?= , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Tvrtko Ursulin Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] drm/sched: Lock spsc_queue_pop() in drm_sched_entity_pop_job() Date: Thu, 10 Sep 2026 09:59:42 +0200 Message-ID: <20260910075942.2000338-4-phasta@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260910075942.2000338-2-phasta@kernel.org> References: <20260910075942.2000338-2-phasta@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" As a preparational step to lock the access of entity->last_scheduled, it is necessary to lock the call to spsc_queue_pop() in drm_sched_entity_pop_job(). The reason is that later the existing lock needs to be moved upward and the relative order between spsc_queue_pop() and drm_sched_rq_pop_entity() needs to be preserved. Guard spsc_queue_pop() with the existing spinlock. Signed-off-by: Philipp Stanner --- drivers/gpu/drm/scheduler/sched_entity.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 274d7a702298..e168f445f2ab 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -563,9 +563,8 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity) */ smp_wmb(); - spsc_queue_pop(&entity->job_queue); - spin_lock(&entity->lock); + spsc_queue_pop(&entity->job_queue); drm_sched_rq_pop_entity(entity); spin_unlock(&entity->lock); -- 2.55.0