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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 4AB9EC433DF for ; Thu, 25 Jun 2020 16:33:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F1CA4206C3 for ; Thu, 25 Jun 2020 16:33:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="n1zHCoNM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F1CA4206C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9DAE18D0002; Thu, 25 Jun 2020 12:33:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 98C4E6B008A; Thu, 25 Jun 2020 12:33:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 853358D0002; Thu, 25 Jun 2020 12:33:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0231.hostedemail.com [216.40.44.231]) by kanga.kvack.org (Postfix) with ESMTP id 6C6E46B0089 for ; Thu, 25 Jun 2020 12:33:03 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2A4D8801A981 for ; Thu, 25 Jun 2020 16:33:03 +0000 (UTC) X-FDA: 76968278646.02.help15_26026ad26e4e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id B97EF30000D69047 for ; Thu, 25 Jun 2020 16:26:20 +0000 (UTC) X-HE-Tag: help15_26026ad26e4e X-Filterd-Recvd-Size: 5886 Received: from userp2120.oracle.com (userp2120.oracle.com [156.151.31.85]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Thu, 25 Jun 2020 16:26:20 +0000 (UTC) Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 05PG7qRB176249; Thu, 25 Jun 2020 16:26:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=u+J0urSX+VPS0JEyukwvvQzOKq9cJrq+hfdXkn5ldnA=; b=n1zHCoNMnP6ZR3D0Xc25mVn17UPByoYPvWFElhYxTDlZMEj9pT3Nx98VHF+SDfbXjuv5 3UBy/XijDQQ3fpqbgIfDEq8tI+cqYaOnAbUuI8wsftkhaODK9gpL/uhz87RFzVxQIMk1 1B94FDBYPiR1BE4ObjHcKo4fwWiJivmpbk1oNhS99c/pX8N406zxLMTwXeuvOlidIzoV 4gcYPLzhTFn5DfzgixJA4/sORyEYZQWNweZz6fzR8O8Lqiev1kNksh0gVQ9UskyQjsvG bY3irJkjm8IvjcYg66s4dbzxGX+MGVDGREZWPJsN7rA4bdh5E9GUzjtcng1r9LUfBBS7 1A== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 31uustsh3h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 25 Jun 2020 16:26:07 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 05PG9ROi063312; Thu, 25 Jun 2020 16:24:07 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 31uurssrh4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Jun 2020 16:24:07 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 05PGO31n003645; Thu, 25 Jun 2020 16:24:03 GMT Received: from [10.159.156.197] (/10.159.156.197) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 25 Jun 2020 16:24:03 +0000 Subject: Re: [RFC] Make the memory failure blast radius more precise To: "Luck, Tony" , Matthew Wilcox Cc: Borislav Petkov , Naoya Horiguchi , "linux-edac@vger.kernel.org" , "linux-mm@kvack.org" , "linux-nvdimm@lists.01.org" , "Darrick J. Wong" , David Rientjes , Mike Kravetz , "Dr. David Alan Gilbert" , Peter Xu , Andrea Arcangeli References: <20200623201745.GG21350@casper.infradead.org> <20200623220412.GA21232@agluck-desk2.amr.corp.intel.com> <20200623221741.GH21350@casper.infradead.org> <20200623222658.GA21817@agluck-desk2.amr.corp.intel.com> <20200623224027.GI21350@casper.infradead.org> <24367ca1-ecb0-de96-b9e5-f94747838c74@oracle.com> <3908561D78D1C84285E8C5FCA982C28F7F67BB29@ORSMSX115.amr.corp.intel.com> From: Jane Chu Organization: Oracle Corporation Message-ID: <5aecb2f9-413f-acbb-f2ea-be75589725c6@oracle.com> Date: Thu, 25 Jun 2020 09:23:57 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F7F67BB29@ORSMSX115.amr.corp.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9663 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 phishscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 bulkscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006250102 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9663 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 mlxlogscore=999 cotscore=-2147483648 adultscore=0 bulkscore=0 spamscore=0 phishscore=0 suspectscore=0 priorityscore=1501 lowpriorityscore=0 clxscore=1015 impostorscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006250102 X-Rspamd-Queue-Id: B97EF30000D69047 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 6/24/2020 5:13 PM, Luck, Tony wrote: >> Both the RFC patch and the above 5-step recovery plan look neat, step 4) >> is nice to carry forward on icelake when a single instruction to clear >> poison is available. > > Jane, > > Clearing poison has some challenges. > > On persistent memory it probably works (as the DIMM is going to remap that address to a different > part of the media to avoid the bad spot). > > On DDR memory you'd need to decide whether the problem was transient, so that a simple > overwrite fixes the problem. Or persistent ... in which case the problem will likely come back > with the right data pattern. To tell that you may need to run some memory test on the affected > area. > > If the error was just in a 4K page, I'd be inclined to copy the good data to a new page and > map that in instead. Throwing away one 4K page isn't likely to be painful. > > If it is in a 2M/1G page ... perhaps it is worth the effort and risk of trying to clear the poison > in place to avoid the pain of breaking up a large page. Thanks! Yes I was only thinking about persistent memory, but memory_failure_dev_pagemap() applies to DDR as well depends on the underlying technology. In our use case, even if the error was just in a 4K page, we'd like to clear the poison and reuse the page to maintain a contiguous 256MB extent in the filesystem. Perhaps it is better to leave that to the filesystem and driver. Regards, -jane > > -Tony >