From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) (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 3BBAE2EAF7 for ; Fri, 17 Jan 2025 01:22:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737076943; cv=none; b=mahU7mO8nRmwzK2UuwsXWkrEshW6aPzu/pEojYiEMXBN0kbcri/DSm1Lc/sCnhsFd23qkbCrekHZQwCWYUEFHqVri59+QwEBRkQUk97qukSmhouN2Hr33WxNsO/3xGLIKbZqVLB2ehCnhMUjxfm5x0hy8Ds/gkgLoR/Jr1BBFso= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737076943; c=relaxed/simple; bh=bIAEQw9SEREN9bN/g6nTYd3Lo0K9K/nhKhTuWQSKYiA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=bmstzaZFNbqio68mbwGRVdR2HVPxwrCfjY9ruObDXP8n7YjhLDLKczH9dugMedBxlci7j7o0eOESm6Ya8gDm/D5QlpEd71o56R5zZOs8z4oTqDT9Q0ldnrWuJlMnIMoqH3Q/2ZSqcLVBr+vfFY19aCDOMADWOswwKJRGHNqHv8k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=lNft5BqQ; arc=none smtp.client-ip=192.198.163.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="lNft5BqQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1737076942; x=1768612942; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=bIAEQw9SEREN9bN/g6nTYd3Lo0K9K/nhKhTuWQSKYiA=; b=lNft5BqQpAz4g4yhiemBcKmeCoOY4F4zUNqZshBuJxTD3XOKY7izyKJU 2d3P6y+aZxNygxKM7q9Rb//HmOOyI531GA2zUnHfwyO1NGa2qwLggu+MS D2h9k5ZeYRkd/T20v/7esqScDodn34Q9ckDIf4NGg+PYrbdasZoPzCcoO +zPO9B2zWkPXlCT/OG8L8mvFTdoXSvFCqhdc/cfXduMMwOxcjsZCVLIZI BD2HdXzvR/4UnCloFcaAXUTxRYfq+5BvZbeIeHZzMH7/uNVSSc/SA2e0c gM/vQDRni9cyGVd0XwKXSIuZ2b0q0JG8vLcRgGZgzkkW5NG9Iy9ybyM3Z A==; X-CSE-ConnectionGUID: l9JQwwwuQs2/wNBBuJlNjA== X-CSE-MsgGUID: avy1RGpJR4O3D1Ia5jEm8g== X-IronPort-AV: E=McAfee;i="6700,10204,11317"; a="37729911" X-IronPort-AV: E=Sophos;i="6.13,210,1732608000"; d="scan'208";a="37729911" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jan 2025 17:22:21 -0800 X-CSE-ConnectionGUID: Z5IBcVErSEqWGPuVqJ7rRg== X-CSE-MsgGUID: B/z4v21jT/aA4DPJiCZ95A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="110295406" Received: from allen-sbox.sh.intel.com (HELO [10.239.159.30]) ([10.239.159.30]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Jan 2025 17:22:20 -0800 Message-ID: <18804ca2-bb8f-46ae-8cce-4c4c3443e027@linux.intel.com> Date: Fri, 17 Jan 2025 09:20:04 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Suspicious RCU usage in enable_drhd_fault_handling() To: Breno Leitao Cc: Ido Schimmel , iommu@lists.linux.dev, dwmw2@infradead.org, tglx@linutronix.de, peterz@infradead.org, linux-kernel@vger.kernel.org References: <20250116-ludicrous-mature-ferret-8956dc@leitao> Content-Language: en-US From: Baolu Lu In-Reply-To: <20250116-ludicrous-mature-ferret-8956dc@leitao> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/16/25 21:34, Breno Leitao wrote: > On Tue, Oct 29, 2024 at 09:15:55AM +0800, Baolu Lu wrote: >> On 2024/10/28 16:43, Ido Schimmel wrote: >>> Hi, >>> >>> I have recently enabled CONFIG_RCU_EXPERT and CONFIG_PROVE_RCU_LIST in >>> our debug configuration file and started observing the following splat >>> [1] on one of our machines during boot. Searched the archives, but did >>> not find a similar report. >>> >>> Not sure what is the right fix as I am not familiar with this code, but >>> I can easily test patches. >> Thanks for reporting this issue. I've been able to reproduce it locally >> and will work on a fix. I'll let you know as soon as I have an update. > Have you had a chance to look at this problem? I am still seeing it in > 6.13-rc7. Yes. I have spent some time on this, but I haven't yet figured out a simple way to fix it. I tried to add the rcu lock or use the dmar_global_lock instead, but neither proved successful. Perhaps it's time to reconsider the locking scheme for those lists. Thanks, baolu