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 X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE390C352A2 for ; Fri, 7 Feb 2020 09:05:10 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 9304A2082E for ; Fri, 7 Feb 2020 09:05:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9304A2082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 292C96FBDB; Fri, 7 Feb 2020 09:05:09 +0000 (UTC) X-Greylist: delayed 464 seconds by postgrey-1.36 at gabe; Fri, 07 Feb 2020 09:05:07 UTC Received: from spamshield.firefly-cloud.com (ec2-52-211-27-78.eu-west-1.compute.amazonaws.com [52.211.27.78]) by gabe.freedesktop.org (Postfix) with ESMTP id C35B36FBDB for ; Fri, 7 Feb 2020 09:05:07 +0000 (UTC) Received: from spamshield.firefly-cloud.com (localhost [127.0.0.1]) by spamshield.firefly-cloud.com (Postfix) with ESMTP id C31031CC59F for ; Fri, 7 Feb 2020 08:57:22 +0000 (GMT) Received: from localhost (localhost [127.0.0.1]) by spamshield.firefly-cloud.com (Postfix) with ESMTP id C12661CC5E3 for ; Fri, 7 Feb 2020 08:57:22 +0000 (GMT) X-Virus-Scanned: by SpamTitan at eu-west-1.compute.internal Received: from spamshield.firefly-cloud.com (localhost [127.0.0.1]) by spamshield.firefly-cloud.com (Postfix) with ESMTP id AE6451CC5A6 for ; Fri, 7 Feb 2020 08:57:21 +0000 (GMT) Authentication-Results: spamshield.firefly-cloud.com; none Received: from fireflyinternet.com (unknown [77.68.26.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by spamshield.firefly-cloud.com (Postfix) with ESMTPS id EC9E71CC59F for ; Fri, 7 Feb 2020 08:57:19 +0000 (GMT) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 20144920-1500050 for multiple; Fri, 07 Feb 2020 08:57:08 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 7 Feb 2020 08:57:08 +0000 Message-Id: <20200207085708.2711257-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200206204915.2636606-3-chris@chris-wilson.co.uk> References: <20200206204915.2636606-3-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2] drm/i915/gt: Protect execlists_hold/unhold from new waiters X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" As we may add new waiters to a request as it is being run, we need to mark the list iteration as being safe for concurrent addition. v2: Mika spotted that we used the same trick for signalers_list, so warn the compiler about the lockless walk there as well. Fixes: 32ff621fd744 ("drm/i915/gt: Allow temporary suspension of inflight requests") Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Mika Kuoppala --- drivers/gpu/drm/i915/gt/intel_lrc.c | 11 ++++++++--- drivers/gpu/drm/i915/i915_scheduler.c | 2 +- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index b350e01d86d2..ed1e4d883d47 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1620,6 +1620,11 @@ last_active(const struct intel_engine_execlists *execlists) &(rq__)->sched.waiters_list, \ wait_link) +#define for_each_signaler(p__, rq__) \ + list_for_each_entry_lockless(p__, \ + &(rq__)->sched.signalers_list, \ + signal_link) + static void defer_request(struct i915_request *rq, struct list_head * const pl) { LIST_HEAD(list); @@ -2378,7 +2383,7 @@ static void __execlists_hold(struct i915_request *rq) list_move_tail(&rq->sched.link, &rq->engine->active.hold); i915_request_set_hold(rq); - list_for_each_entry(p, &rq->sched.waiters_list, wait_link) { + for_each_waiter(p, rq) { struct i915_request *w = container_of(p->waiter, typeof(*w), sched); @@ -2464,7 +2469,7 @@ static bool hold_request(const struct i915_request *rq) * If one of our ancestors is on hold, we must also be on hold, * otherwise we will bypass it and execute before it. */ - list_for_each_entry(p, &rq->sched.signalers_list, signal_link) { + for_each_signaler(p, rq) { const struct i915_request *s = container_of(p->signaler, typeof(*s), sched); @@ -2496,7 +2501,7 @@ static void __execlists_unhold(struct i915_request *rq) RQ_TRACE(rq, "hold release\n"); /* Also release any children on this engine that are ready */ - list_for_each_entry(p, &rq->sched.waiters_list, wait_link) { + for_each_waiter(p, rq) { struct i915_request *w = container_of(p->waiter, typeof(*w), sched); diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c index 9cbd31443eb0..a9666df1d842 100644 --- a/drivers/gpu/drm/i915/i915_scheduler.c +++ b/drivers/gpu/drm/i915/i915_scheduler.c @@ -432,7 +432,7 @@ bool __i915_sched_node_add_dependency(struct i915_sched_node *node, !node_started(signal)) node->flags |= I915_SCHED_HAS_SEMAPHORE_CHAIN; - list_add(&dep->signal_link, &node->signalers_list); + list_add_rcu(&dep->signal_link, &node->signalers_list); list_add_rcu(&dep->wait_link, &signal->waiters_list); /* -- 2.25.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx