Received: by 2002:a05:6a10:5bc5:0:0:0:0 with SMTP id os5csp1945142pxb; Thu, 4 Nov 2021 11:12:39 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxalTwg4FvB7ifN7Y2FeNQWsMRryxo0cvF8+kIyLqGwc2lSKN+rzm03MM8tPpYw/ZIs7xGK X-Received: by 2002:a17:907:3f07:: with SMTP id hq7mr52902165ejc.420.1636049559024; Thu, 04 Nov 2021 11:12:39 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1636049559; cv=none; d=google.com; s=arc-20160816; b=vwx3zlK6H+5xhNoDrBzMeeJiXTc6zAMYcLCQ6LA2qn4hoGie8oMkZZMyy3Ye7+K7aX cVGkjo1+jNWyG6rGySIkzAZesiTSqo0m+Qj48Fk2ne+3S5wdiTC99yaARwYFKqVma6U8 ujn8RDrUmEG1pDkAknnlEdKJJEJig3wNLr9tWguUpAV/Uw2e3np/bWa5dZzme3FEUsfY kYCpuucjqGt/DuDtbl8bvSf4r+s1EDjK/cSYaEnLgDZdS9viVxJjZCFRmrDISeS7Bu+F 0sEBYDBxDgoldlwd4hubgkuifpjrjsyaYuSSu/O6MrtHmjY+wWy0urBj7A8M2AiqX65p 5tkQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=X/zx02lrok+YXE3fHYCnesmy30oZEd5gQFjWswEssO8=; b=GJncudzuhOMKNjz1X87dRlmxPcxMEvirRbt7qrE7f15Y2qjDKZohTNxp0Q/bA0bJzY m+cQmLXww3gKvucx8Qw//E4ijm3El7qPAtMqHhYE4sQ90Yga2PJO6oKuFWuD5i0a9okN XeCLUfIonscKuJi6VcNA0jyg0IvBkvxHjK87z2sGJkqt4eGBbe48cpPJOnj8SNVlOkXz 7XmxZM0Jx3Gqwsy+7A3/fuFngMJa8/Ukv3d/x29ey/vM3/RQEELnwvb2KPyUHgs5pZ9v GO5V7Z4TeR/aHykAYbTswYK3z17V9cnAg4igBuD455OryTnOxJY6XtYUB4qVQCExhJra JNng== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=Sbg76vqB; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id nd25si13003464ejc.391.2021.11.04.11.12.14; Thu, 04 Nov 2021 11:12:39 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=Sbg76vqB; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234083AbhKDSM0 (ORCPT + 99 others); Thu, 4 Nov 2021 14:12:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232152AbhKDSM0 (ORCPT ); Thu, 4 Nov 2021 14:12:26 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1328C061714; Thu, 4 Nov 2021 11:09:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=X/zx02lrok+YXE3fHYCnesmy30oZEd5gQFjWswEssO8=; b=Sbg76vqBUrKRwSH8VKRkJgiUCC r1oyKJ79d1QE9fOCCZaLTLXMc2ew6uKuULTjgBflx8d78VPVr2homn7rL3kQVHvP7Ak9/wM0MbpSy YSrJUXTFHpxtX4i3XpHfoy8u4fm08G+Cx16cTwYn/LBCFS7Lv3f39xVI6zKCrHqps5FJzI6XW50qi 8xgjF5t15JvLZTKg6czUDnDkLd8NyrCoKV5fYiMDj6WPdVlgUuSxgdjCS10DIR/kWUthyM54DNI3M 3ulIl7eI4ED25BAW7Mc3MlXqYoWF5f6UgyROaM1IDdmMYVmXaRrN/V/m7JIC73SF58NYKDj27R5M0 Cc4GufhA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mih7J-0062bO-LC; Thu, 04 Nov 2021 18:06:22 +0000 Date: Thu, 4 Nov 2021 18:05:37 +0000 From: Matthew Wilcox To: Christoph Hellwig Cc: Dan Williams , "Darrick J. Wong" , Jane Chu , "david@fromorbit.com" , "vishal.l.verma@intel.com" , "dave.jiang@intel.com" , "agk@redhat.com" , "snitzer@redhat.com" , "dm-devel@redhat.com" , "ira.weiny@intel.com" , "vgoyal@redhat.com" , "linux-fsdevel@vger.kernel.org" , "nvdimm@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-xfs@vger.kernel.org" Subject: Re: [dm-devel] [PATCH 0/6] dax poison recovery with RWF_RECOVERY_DATA flag Message-ID: References: <2102a2e6-c543-2557-28a2-8b0bdc470855@oracle.com> <20211028002451.GB2237511@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 04, 2021 at 10:43:23AM -0700, Christoph Hellwig wrote: > Well, the answer for other interfaces (at least at the gold plated > cost option) is so strong internal CRCs that user visible bits clobbered > by cosmic rays don't realisticly happen. But it is a problem with the > cheaper ones, and at least SCSI and NVMe offer the error list through > the Get LBA status command (and I bet ATA too, but I haven't looked into > that). Oddly enough there has never been much interested from the > fs community for those. "don't realistically happen" is different when you're talking about "doesn't happen within the warranty period of my laptop's SSD" and "doesn't happen on my fleet of 10k servers before they're taken out of service". There's also a big difference in speeds between an NVMe drive (7GB/s) and a memory device (20-50GB/s). The UBER being talked about when I was still at Intel was similar to / slightly better than DRAM, but that's still several failures per year across an entire data centre that's using pmem flat-out.