From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (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 03D262D05E for ; Fri, 28 Jun 2024 05:27:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719552471; cv=none; b=QdzNAlbQlXM2xZ46kLoVriCT7OIlXv4Qo/fQyze1k7BmIxM5uTC+dQH+Au+pxP5W65YITBWCsDdOqc7KSZcHMDkggstHkwY9shcr9nyDJdkUgrTCNg2SVNyfjnJdjTQxeilOObbMDhDzXunpa7rVjoFeAXgh/2g/0xTFEtom9Lo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719552471; c=relaxed/simple; bh=EbWFE2VnTSRfIqIsYblunUdrhQzg/C0mSK2Ujk57jGg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=hiG1jgA+/mf+GBHLrlZ7h2PwlVVmBmY3gJh7N2uGeJRLAkMyx6ELYinZDq+KW/JPS9VBhL1s505myzfPQYNFVhp6Ec0DE1R0CuGEbZ9RWXyoLcyv6aIGQvE3ZIo1xzFCf8rTryF1Q55vV3Qs1xyNYRJIcgPwte5pg+6Ebbe7Qlo= 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=dvvywQi4; arc=none smtp.client-ip=192.198.163.12 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="dvvywQi4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1719552469; x=1751088469; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=EbWFE2VnTSRfIqIsYblunUdrhQzg/C0mSK2Ujk57jGg=; b=dvvywQi4YYKYnoumopw65Ae9pER4nlnlMGcrcSFRN97xvfJI6qZ6TY53 bJ9wWOqIfidbZ2643qw+Fun6xhcmeNHrtGwz4tN1MtneHeZn5qfcDBKjZ 5sL1v+LXYhjXJTdpdUC4kfrrHpa43s/Ocbx4TBuQ6khf+pqXXkkJPkcFN oGRKU32jrbU3MLwc4EA/4o5kWHXCODdhTh9vI1IN+D3OzFvFbAFoQ1H/Y KHACrOoOl93UC417Qsr0NYMbPwU6jzSg847ISUaE/9rjLLNkMcevqa32x X4VGYQl2bl+FxBi5CGxISfpPY4Zv9oyMviMAEAfSSc13j2w8jbbYIvVmH w==; X-CSE-ConnectionGUID: 6KizJdhdS1WEAUiKJLmCOA== X-CSE-MsgGUID: EjxzyoO9Ss634TDZe41Lyg== X-IronPort-AV: E=McAfee;i="6700,10204,11116"; a="20593221" X-IronPort-AV: E=Sophos;i="6.09,168,1716274800"; d="scan'208";a="20593221" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2024 22:27:48 -0700 X-CSE-ConnectionGUID: qrvTILA6TI6zx5MgNg1xmw== X-CSE-MsgGUID: W50Q72weR1SfU3HNkX4jxA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,168,1716274800"; d="scan'208";a="49085086" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.54.38.190]) by fmviesa005.fm.intel.com with ESMTP; 27 Jun 2024 22:27:48 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id E9A88302A3B; Thu, 27 Jun 2024 22:27:47 -0700 (PDT) From: Andi Kleen To: Ruidong Tian Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, nao.horiguchi@gmail.com, linmiaohe@huawei.com, tianruidong@alibaba.linux.com, xueshuai@linux.alibaba.com Subject: Re: [PATCH] mm/hwpoison: avoid speculation access after soft/hard offline In-Reply-To: <20240628033509.27612-1-tianruidong@linux.alibaba.com> (Ruidong Tian's message of "Fri, 28 Jun 2024 11:35:09 +0800") References: <20240628033509.27612-1-tianruidong@linux.alibaba.com> Date: Thu, 27 Jun 2024 22:27:47 -0700 Message-ID: <871q4hzlf0.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Ruidong Tian writes: > Page that offlined can report CE/UE event due to speculation access. > Delete kernel 1:1 linner mapping after soft/hard offline to avoid it. But that will split the large pages for the direct mapping, costing you every time there is TLB pressure. You can probably do the math, with enough uptime and a reasonable error rate aand this patch there might be not even be 2MB pages left at some point. Cheaper to just ignore them, since they shouldn't cause any other problems. -Andi