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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 49FB2C12002 for ; Fri, 16 Jul 2021 14:32:50 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id D931D613F8 for ; Fri, 16 Jul 2021 14:32:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D931D613F8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43834 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m4OtU-0002D5-TC for qemu-devel@archiver.kernel.org; Fri, 16 Jul 2021 10:32:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50098) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m4Osj-0001Vo-8K for qemu-devel@nongnu.org; Fri, 16 Jul 2021 10:32:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:38329) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m4Osf-0007j3-34 for qemu-devel@nongnu.org; Fri, 16 Jul 2021 10:32:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626445915; 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: in-reply-to:in-reply-to:references:references; bh=1DCs0/Brf8tltpqdJUJlgMpBEloYxuYZMJMa2uZpXG0=; b=JPuEPb5NETde432pyEQfhEQsAlla24Gu3aSi1eRlPdwLNDcfzq1MgT4yhEC9gPxxKqZFNt t76pjKFVvkvVNk+BAYv+OK2VGyeIepp7YbovkxdHm2+aSEJr6keU3lBHm/aLcqUCRZno1d LxS/J4hwT+ZWIrJLzRTuuxolfkgKLJY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-602-uUUx280ONsi6GeRjDuCEKg-1; Fri, 16 Jul 2021 10:31:53 -0400 X-MC-Unique: uUUx280ONsi6GeRjDuCEKg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 63A109F933; Fri, 16 Jul 2021 14:31:52 +0000 (UTC) Received: from redhat.com (ovpn-113-8.ams2.redhat.com [10.36.113.8]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 55E495C1A3; Fri, 16 Jul 2021 14:31:51 +0000 (UTC) Date: Fri, 16 Jul 2021 16:31:49 +0200 From: Kevin Wolf To: Peter Maydell Subject: Re: intermittent hang in qos-test for qemu-system-i386 on 32-bit arm host Message-ID: References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.7, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: QEMU Developers , Coiby Xu , Raphael Norwitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 11.07.2021 um 17:53 hat Peter Maydell geschrieben: > On Sat, 10 Jul 2021 at 14:30, Peter Maydell wrote: > > > > I've noticed recently that intermittently 'make check' will hang on > > my aarch32 test system (really an aarch64 box with an aarch32 chroot). > > > > I think from grep that this must be the vhost-user-blk test. > > I've also now seen this on qemu-system-i386 guest x86-64 Linux host: Your two stack traces look very different to me, the common thing is just that one process requests something and the other seems to have ignored it and is just idle. In the first stack trace, it was the qtest sending the very first command ('endianness') over the qtest socket and QEMU seemed to ignore it. In the second stack trace, it is the vhost-user-blk realize() code in QEMU sending a request to the export in qemu-storage-daemon and never getting an answer. If this is the same bug, it looks to me as if it's something with the event notification in the main loop? Can we check if there would actually be an event pending in the apparently idle process if ppoll() returned? Kevin