From patchwork Tue Aug 13 10:25:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tvrtko Ursulin X-Patchwork-Id: 13761745 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 CDF0BC52D7D for ; Tue, 13 Aug 2024 10:25:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 23C2F10E2DE; Tue, 13 Aug 2024 10:25:16 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=igalia.com header.i=@igalia.com header.b="h+QPiFjL"; dkim-atps=neutral Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id 232A710E2DD for ; Tue, 13 Aug 2024 10:25:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=RmMAaQVLm22R4ky3+deRS6uCjPL1oBLCXQkikvomZHM=; b=h+QPiFjL6JDkVQwAbqCYzt3YWu ncU81jOWWiEHXqei1BAPF5X+LaNEEjHss1H8/83MTCWdnebF8puhmOASRy+UwOZpT1Dgc4Ivpbq3Y KCYDkHVfAtmJt3rLj9k3LNtmhMOGLqXiBp9yy78H+3W+KhqGegFEStH+mTz2hoOcVJmrsNLlB62RA YXM57586KJvvJDT3Aj1PRs/ojukLLZX7FxJ4eXfXueAQlRavaURfsQnmnMvhbvkOsKhIo0nlinVCJ dXUWUfVYIifO+s8ZUmFk+lzNb5XW1TwW8oTQCZhMsNmhhsmASzvMr7SrKUw+vtIa7uarbRPnOuIB6 iAyy6T8Q==; Received: from [84.69.19.168] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1sdoiC-00Bsut-0b; Tue, 13 Aug 2024 12:25:08 +0200 From: Tvrtko Ursulin To: dri-devel@lists.freedesktop.org Cc: kernel-dev@igalia.com, Tvrtko Ursulin , =?utf-8?q?Ma=C3=ADra_Canal?= , stable@vger.kernel.org Subject: [PATCH 1/2] drm/v3d: Disable preemption while updating GPU stats Date: Tue, 13 Aug 2024 11:25:04 +0100 Message-ID: <20240813102505.80512-1-tursulin@igalia.com> X-Mailer: git-send-email 2.44.0 MIME-Version: 1.0 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" From: Tvrtko Ursulin We forgot to disable preemption around the write_seqcount_begin/end() pair while updating GPU stats: [ ] WARNING: CPU: 2 PID: 12 at include/linux/seqlock.h:221 __seqprop_assert.isra.0+0x128/0x150 [v3d] [ ] Workqueue: v3d_bin drm_sched_run_job_work [gpu_sched] <...snip...> [ ] Call trace: [ ] __seqprop_assert.isra.0+0x128/0x150 [v3d] [ ] v3d_job_start_stats.isra.0+0x90/0x218 [v3d] [ ] v3d_bin_job_run+0x23c/0x388 [v3d] [ ] drm_sched_run_job_work+0x520/0x6d0 [gpu_sched] [ ] process_one_work+0x62c/0xb48 [ ] worker_thread+0x468/0x5b0 [ ] kthread+0x1c4/0x1e0 [ ] ret_from_fork+0x10/0x20 Fix it. Signed-off-by: Tvrtko Ursulin Fixes: 6abe93b621ab ("drm/v3d: Fix race-condition between sysfs/fdinfo and interrupt handler") Cc: Maíra Canal Cc: # v6.10+ Acked-by: Maíra Canal --- drivers/gpu/drm/v3d/v3d_sched.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c index 42d4f4a2dba2..cc2e5a89467b 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -136,6 +136,8 @@ v3d_job_start_stats(struct v3d_job *job, enum v3d_queue queue) struct v3d_stats *local_stats = &file->stats[queue]; u64 now = local_clock(); + preempt_disable(); + write_seqcount_begin(&local_stats->lock); local_stats->start_ns = now; write_seqcount_end(&local_stats->lock); @@ -143,6 +145,8 @@ v3d_job_start_stats(struct v3d_job *job, enum v3d_queue queue) write_seqcount_begin(&global_stats->lock); global_stats->start_ns = now; write_seqcount_end(&global_stats->lock); + + preempt_enable(); } static void @@ -164,8 +168,10 @@ v3d_job_update_stats(struct v3d_job *job, enum v3d_queue queue) struct v3d_stats *local_stats = &file->stats[queue]; u64 now = local_clock(); + preempt_disable(); v3d_stats_update(local_stats, now); v3d_stats_update(global_stats, now); + preempt_enable(); } static struct dma_fence *v3d_bin_job_run(struct drm_sched_job *sched_job)