From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90E9EA47 for ; Mon, 28 Oct 2024 04:46:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730090788; cv=none; b=HU/9FDRTA4Zw4BBii+7D+4PlJdFflTvj6eWC2MPMAwdRaUi5kBf0xCVHa8lwGVupCgM7nEOaweDpsV6izPWcDrgbAsLRRijTCvkgsOyIlE/WR0aNm//tW8/SkVlRpvs19Pz9H5m8orTyYFWY1Vf7njsSXHNSE5wVPlwxXUYAteA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730090788; c=relaxed/simple; bh=2EbHWBfLhGkuOGHGIk7T56Pwh0KL7XKK8so6hCxKmC0=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=PI8Q8boTdezNlhrO0yIAww7+ZdZ6GtVdEzCuVV4L8IziNz56zG4LTcfSNjJG35p9Akv05b46aw4Vkf/GBMd1xKv+HZzaBChd6VidaI/BlyAfWMNlkvSpUgrQhO2D0bkAPNZgJJLTR8i1fDDBamDTXuikcyhOFNnoIVE4clPSMds= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=arqpY7Em; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="arqpY7Em" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-20c70abba48so28908675ad.0 for ; Sun, 27 Oct 2024 21:46:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1730090786; x=1730695586; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=Ru6TZnJsC9elzyNrY/cvzQ4CwnpZ6FeXob1OQjHoMmg=; b=arqpY7EmgtRpliEc5oseVdMl5rD5Wad0juTh689491S9BLB2t1oCVCwHZ9YlJ9yinr KUmHUfKPjQPPShW0n6mSvb9stwypPLLL8OBtT84EUOlHoJYX9ikqB0Yb5AVf/NMSMhG2 62+noveLxjRANAdNV5iOAyQAp0XuXjEPMY6rg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730090786; x=1730695586; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Ru6TZnJsC9elzyNrY/cvzQ4CwnpZ6FeXob1OQjHoMmg=; b=WYhvwyJzjIFhALZWb67ILIDAiq5CNdlRjgtOtYq36RmZOUS0Un542NPUJAOtYvMj17 0hjvfHIqz+USrA0udxE46qJMQlXOxnQP8GSliobfjEWuijyq6LGenHABKa2Dius/LAtm B+Efrg+9L4BKg8tN7mjwApYkg7ZL5PNbrMQi8He9ESQKroknvEzfmvSzzHg7PN/xbQoJ mtUyqz+GTNFCPorRqu7PII9RemM6kGQEI3HnQJ6OtcFcru0JhVbGoJCnl79adSuEKH6A 8jAYbyBDfEaW+GyS1tADbRXByZMcbUoAdoAIESjZi4mzIMYi324uN8nBSFHF3unlvVmi /xGg== X-Gm-Message-State: AOJu0YwZvVpAIdboTAkCrxIzFHLhZh42IyfI3tNNYJoHtnAkZG1UpZtE jidjA7PaL44xpHqDXPEIRVy8wXXjO3P48V3an1NZYJplyqQBy8JGQLFjnrtyig== X-Google-Smtp-Source: AGHT+IG4o8SyC/xd2sK4623mdcAb/BEs5cFjcwjBL9FvVlKtFVsTbOeeecs/bZqY7tko4MXRQ5EkAA== X-Received: by 2002:a17:902:e883:b0:20c:7d75:bd5b with SMTP id d9443c01a7336-210c6c75ae4mr88521365ad.42.1730090785735; Sun, 27 Oct 2024 21:46:25 -0700 (PDT) Received: from google.com ([2401:fa00:8f:203:33df:d367:fdc8:47a0]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-210bbf464ecsm43014535ad.28.2024.10.27.21.46.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Oct 2024 21:46:25 -0700 (PDT) Date: Mon, 28 Oct 2024 13:46:21 +0900 From: Sergey Senozhatsky To: David Airlie , Simona Vetter Cc: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: i915: intel_gt_reset() deadlock Message-ID: <20241028044621.GS1279924@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi, I'm currently looking at i915 deadlock report, the report is for 5.15, but I don't see any significant difference in linux-next code, so it looks relevant to current upstream code. Basically, intel_gt_reset() grabs gt->reset.mutex and then sleeps in flush_work(). Worker, meanwhile, cannot make progress because it sleeps on gt->reset.mutex in intel_gt_set_wedged(). INFO: task kworker/2:1:68 blocked for more than 122 seconds. Tainted: G U W 5.15.135-lockdep-20721-gd26c0f5bff55 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/2:1 state:D stack:26184 pid: 68 ppid: 2 flags:0x00004000 Workqueue: events intel_wedge_me Call Trace: __schedule+0xe1b/0x3bae schedule+0xc8/0x247 schedule_preempt_disabled+0x18/0x28 __mutex_lock_common+0x99f/0x1532 mutex_lock_nested+0x20/0x2a intel_gt_set_wedged+0xbf/0x122 process_one_work+0x8f0/0x157c worker_thread+0x4c2/0xa4a kthread+0x32b/0x442 ret_from_fork+0x1f/0x30 INFO: task kworker/2:1H:156 blocked for more than 122 seconds. Tainted: G U W 5.15.135-lockdep-20721-gd26c0f5bff55 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/2:1H state:D stack:27112 pid: 156 ppid: 2 flags:0x00004000 Workqueue: events_highpri heartbeat Call Trace: __schedule+0xe1b/0x3bae schedule+0xc8/0x247 schedule_timeout+0x15e/0x215 do_wait_for_common+0x2d3/0x3f9 wait_for_completion+0x51/0x5d __flush_work+0xd9/0x131 __cancel_work_timer+0x247/0x544 intel_guc_submission_reset_prepare+0xbf/0xb01 intel_uc_reset_prepare+0x11c/0x1e0 reset_prepare+0x35/0x20d intel_gt_reset+0x3c3/0xa3d intel_gt_handle_error+0xb4b/0xf24 heartbeat+0xaa7/0xce5 process_one_work+0x8f0/0x157c worker_thread+0x4c2/0xa4a kthread+0x32b/0x442 ret_from_fork+0x1f/0x30