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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D2D6CDB47E for ; Thu, 12 Oct 2023 08:17:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235303AbjJLIRJ (ORCPT ); Thu, 12 Oct 2023 04:17:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234125AbjJLIRI (ORCPT ); Thu, 12 Oct 2023 04:17:08 -0400 Received: from out30-101.freemail.mail.aliyun.com (out30-101.freemail.mail.aliyun.com [115.124.30.101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33DB791; Thu, 12 Oct 2023 01:17:05 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R511e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=xueshuai@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0Vtzoqpa_1697098619; Received: from 30.240.114.194(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0Vtzoqpa_1697098619) by smtp.aliyun-inc.com; Thu, 12 Oct 2023 16:17:01 +0800 Message-ID: Date: Thu, 12 Oct 2023 16:16:58 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH] HWPOISON: add a pr_err message when forcibly send a sigbus Content-Language: en-US From: Shuai Xue To: Helge Deller , Will Deacon , "Luck, Tony" Cc: catalin.marinas@arm.com, James.Bottomley@HansenPartnership.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org References: <20230819102212.21103-1-xueshuai@linux.alibaba.com> <20230821105025.GB19469@willie-the-truck> <44c4d801-3e21-426b-2cf0-a7884d2bf5ff@linux.alibaba.com> <54114b64-4726-da46-8ffa-16749ec0887a@linux.alibaba.com> <20230830221814.GB30121@willie-the-truck> <2540b570-1c1a-7d1b-59e9-6c32d9947c44@linux.alibaba.com> In-Reply-To: <2540b570-1c1a-7d1b-59e9-6c32d9947c44@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/9/4 18:40, Shuai Xue wrote: > > > On 2023/8/31 17:06, Helge Deller wrote: >> On 8/31/23 05:29, Shuai Xue wrote: >>> On 2023/8/31 06:18, Will Deacon wrote: >>>> On Mon, Aug 28, 2023 at 09:41:55AM +0800, Shuai Xue wrote: >>>>> On 2023/8/22 09:15, Shuai Xue wrote: >>>>>> On 2023/8/21 18:50, Will Deacon wrote: >>>>>>>> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c >>>>>>>> index 3fe516b32577..38e2186882bd 100644 >>>>>>>> --- a/arch/arm64/mm/fault.c >>>>>>>> +++ b/arch/arm64/mm/fault.c >>>>>>>> @@ -679,6 +679,8 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, >>>>>>>>       } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) { >>>>>>>>           unsigned int lsb; >>>>>>>> >>>>>>>> +        pr_err("MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n", >>>>>>>> +               current->comm, current->pid, far); >>>>>>>>           lsb = PAGE_SHIFT; >>>>>>>>           if (fault & VM_FAULT_HWPOISON_LARGE) >>>>>>>>               lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault)); >>>>>>> >>>>>>> Hmm, I'm not convinced by this. We have 'show_unhandled_signals' already, >>>>>>> and there's plenty of code in memory-failure.c for handling poisoned pages >>>>>>> reported by e.g. GHES. I don't think dumping extra messages in dmesg from >>>>>>> the arch code really adds anything. >>>>>> >>>>>> I see the show_unhandled_signals() will dump the stack but it rely on >>>>>> /proc/sys/debug/exception-trace be set. >>>>>> >>>>>> The memory failure is the top issue in our production cloud and also other hyperscalers. >>>>>> We have received complaints from our operations engineers and end users that processes >>>>>> are being inexplicably killed :(. Could you please consider add a message? >>>> >>>> I don't have any objection to logging this stuff somehow, I'm just not >>>> convinced that the console is the best place for that information in 2023. >>>> Is there really nothing better? >> >>> I agree that console might not the better place, but it still plays an important role. >>> IMO the most direct idea for end user to check what happened is to check by viewing >>> the dmesg. In addition, we deployed some log store service collects all cluster dmesg >>> from /var/log/kern. >> >> Right, pr_err() is not just console. >> It ends up in the syslog, which ends up in a lot of places, e.g. through syslog forwarding. >> Most monitoring tools monitor the syslog as well. >> >> So, IMHO pr_err() is the right thing. >> >> Helge >> > > Totally agreed. > > Thank you. > > Best Regards, > Shuai > Hi, Will, Based our discussion in this thread, are you happy to queue this patch? Thank you. Best Regards, Shuai