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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E2B44EEAA4E for ; Thu, 14 Sep 2023 15:36:47 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qgoNp-0000tA-M5; Thu, 14 Sep 2023 11:35:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qgoNn-0000sc-Vj for qemu-devel@nongnu.org; Thu, 14 Sep 2023 11:35:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qgoNl-0004IC-PJ for qemu-devel@nongnu.org; Thu, 14 Sep 2023 11:35:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694705752; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9iHZTSaJ3ekYDv4W0CJUWXaTtOwjmt3niZg23N1KwJs=; b=WovhRZH1GfUqt5FT5wOn/xbDAz4kXhyk2n6HtTxeNOXNkP7QCxfDOM3gcTC21uj0d/Vq39 S22Pf/vhGuDblx18zqsqBduOgsrFJ1HUET/jZS9TwrbBJIq6VkbS0hmMh+BUDsD5zmtV9I hmm8TOJ8w271FHdapU1uJqroEu5//24= Received: from mail-oa1-f69.google.com (mail-oa1-f69.google.com [209.85.160.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-554-wuCmV2FaOFaS9oG3qm8MMA-1; Thu, 14 Sep 2023 11:35:51 -0400 X-MC-Unique: wuCmV2FaOFaS9oG3qm8MMA-1 Received: by mail-oa1-f69.google.com with SMTP id 586e51a60fabf-1a9e3f67989so293949fac.1 for ; Thu, 14 Sep 2023 08:35:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694705750; x=1695310550; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=9iHZTSaJ3ekYDv4W0CJUWXaTtOwjmt3niZg23N1KwJs=; b=CiMIVYyMzuSW1RKitQb4D4S039iiZioPEF7Rp4f714p7AfYPHbWDHQbdPwz4Xp0F7D B6GHhnp62F8COxl8GcEJXnrqJFHvoWg4c/VaGHI12NUa4Og7f4qk4GiQhWBShy041BI+ 5uH802X5kGj6n+h0WPrDSRBC9Uc0XER4gwVPtx7Jf1w9cSfIFvc4t3k1LicSx5bLVN5C gNw0mFYJ5BTKjKE5/AXi8DyU+BGfqPQK3LLJULv9VIxzZRCL2Ge1SC+LsmvbVW4GIZww OOQXm5giH93Hvr34DPZyAcPy+KDAZua4QvZT8Vnpk6fcNcZVmFa4bjNPts3yfYIem0vz e/jA== X-Gm-Message-State: AOJu0YyOYvED0udq4WjLnBP/zEgJiaspZjRBh7sXrX/I4Nsgs+iVEgKG nXcmpGgaqgGV5JAG03/8Pz8QSb50gnVlZ5cavTQIaPJZvZxCbRj4xOmE1CmG6CQFDvlJws95hoZ qJVkyACP6Wh0aME8= X-Received: by 2002:a05:6359:b9c:b0:13f:1503:92f8 with SMTP id gf28-20020a0563590b9c00b0013f150392f8mr4917081rwb.2.1694705750366; Thu, 14 Sep 2023 08:35:50 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEzjQGA88AFJW1dbfKeN942c5glE6of0AhiyaMJD2ykSZeT7wV0nCqIOGO3pQH15WCRve0IvA== X-Received: by 2002:a05:6359:b9c:b0:13f:1503:92f8 with SMTP id gf28-20020a0563590b9c00b0013f150392f8mr4917064rwb.2.1694705749975; Thu, 14 Sep 2023 08:35:49 -0700 (PDT) Received: from x1n (cpe5c7695f3aee0-cm5c7695f3aede.cpe.net.cable.rogers.com. [99.254.144.39]) by smtp.gmail.com with ESMTPSA id d3-20020a0caa03000000b00655e3e86ad7sm555750qvb.6.2023.09.14.08.35.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Sep 2023 08:35:49 -0700 (PDT) Date: Thu, 14 Sep 2023 11:35:47 -0400 From: Peter Xu To: Fabiano Rosas Cc: Stefan Hajnoczi , Juan Quintela , Leonardo Bras , qemu-devel@nongnu.org Subject: Re: QEMU migration-test CI intermittent failure Message-ID: References: <20230913192301.GA917052@fedora> <87r0n1kggo.fsf@suse.de> <87edj0kcz7.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87edj0kcz7.fsf@suse.de> Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, Sep 14, 2023 at 12:10:04PM -0300, Fabiano Rosas wrote: > Peter Xu writes: > > > On Wed, Sep 13, 2023 at 04:42:31PM -0300, Fabiano Rosas wrote: > >> Stefan Hajnoczi writes: > >> > >> > Hi, > >> > The following intermittent failure occurred in the CI and I have filed > >> > an Issue for it: > >> > https://gitlab.com/qemu-project/qemu/-/issues/1886 > >> > > >> > Output: > >> > > >> > >>> QTEST_QEMU_IMG=./qemu-img MALLOC_PERTURB_=116 QTEST_QEMU_STORAGE_DAEMON_BINARY=./storage-daemon/qemu-storage-daemon G_TEST_DBUS_DAEMON=/builds/qemu-project/qemu/tests/dbus-vmstate-daemon.sh QTEST_QEMU_BINARY=./qemu-system-x86_64 /builds/qemu-project/qemu/build/tests/qtest/migration-test --tap -k > >> > ――――――――――――――――――――――――――――――――――――― ✀ ――――――――――――――――――――――――――――――――――――― > >> > stderr: > >> > qemu-system-x86_64: Unable to read from socket: Connection reset by peer > >> > Memory content inconsistency at 5b43000 first_byte = bd last_byte = bc current = 4f hit_edge = 1 > >> > ** > >> > ERROR:../tests/qtest/migration-test.c:300:check_guests_ram: assertion failed: (bad == 0) > >> > (test program exited with status code -6) > >> > > >> > You can find the full output here: > >> > https://gitlab.com/qemu-project/qemu/-/jobs/5080200417 > >> > >> This is the postcopy return path issue that I'm addressing here: > >> > >> https://lore.kernel.org/r/20230911171320.24372-1-farosas@suse.de > >> Subject: [PATCH v6 00/10] Fix segfault on migration return path > >> Message-ID: <20230911171320.24372-1-farosas@suse.de> > > > > Hmm I just noticed one thing, that Stefan's failure is a ram check issue > > only, which means qemu won't crash? > > > > The source could have crashed and left the migration at an inconsistent > state and then the destination saw corrupted memory? > > > Fabiano, are you sure it's the same issue on your return-path fix? > > > > I've been running the preempt tests on my branch for thousands of > iterations and didn't see any other errors. Since there's no code going > into the migration tree recently I assume it's the same error. > > I run the tests with GDB attached to QEMU, so I'll always see a crash > before any memory corruption. Okay, maybe that stops you from seeing the above check_guests_ram() error? Worth checking whether it fails differently always if you just don't attach gdb to it; I had a feeling that it'll always fail in the other way (I think migration-test will say something like "qemu killed" etc. in most cases), further to identify the issues. > > > I'm also trying to reproduce either of them with some loads. I think I hit > > some but it's very hard to reproduce solidly. > > Well, if you find anything else let me know and we'll fix it. I think Stefan's issue is the one I triggered once, but only once; I did see check_guests_ram() lines. I ran concurrently 10 migration-tests (on 8 cores; just to make scheduler start to really work), each looping over preempt/plain for 500 times and hit nothing.. I'm trying again with a larger host with more instances, so far I've run 200 loops over 40 instances running together, I hit nothing.. but I'm keeping trying. -- Peter Xu