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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55526 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lIDqo-0005Eq-5e for qemu-devel@archiver.kernel.org; Fri, 05 Mar 2021 12:02:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:60212) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lIDiM-0005Zk-D8 for qemu-devel@nongnu.org; Fri, 05 Mar 2021 11:54:10 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55111) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lIDiJ-0006O0-3v for qemu-devel@nongnu.org; Fri, 05 Mar 2021 11:54:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614963245; 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=KFMg+CoTo6mnONRoVd2DdNS3rI/CkJgNyKm/Snlhmjw=; b=bkg9aYEfE6T9HNrzMKhC009WMW/XuvLsbvbIzpUfgCI8GxRZ9fO14g7suMF/IR1uwJk5eb 5e9NOvaWbeDvThW5F/KcJK84YppPGGkH6J7aVrJx4XuXyigcYpNOrlmwh9V3ywwKKcpNVC TBzPNR2aG2K6Y+LxnKWrWszvm0noD9o= 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-597-IzW8frESNcm_a4SokNkPzA-1; Fri, 05 Mar 2021 11:54:00 -0500 X-MC-Unique: IzW8frESNcm_a4SokNkPzA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0B52D193F562; Fri, 5 Mar 2021 16:53:59 +0000 (UTC) Received: from [10.10.117.80] (ovpn-117-80.rdu2.redhat.com [10.10.117.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 007A21053B20; Fri, 5 Mar 2021 16:53:55 +0000 (UTC) Subject: Re: [RESEND][BUG FIX HELP] QEMU main thread endlessly hangs in __ppoll() To: Like Xu References: <06dec6f0-d720-ce7b-8485-8be1954418bb@redhat.com> <624a6256-a735-6475-8831-b4c85f225c94@linux.intel.com> From: John Snow Message-ID: Date: Fri, 5 Mar 2021 11:53:55 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <624a6256-a735-6475-8831-b4c85f225c94@linux.intel.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , "Thomas Huth \(S390-ccw/CHRP/qtest/GitLab\)" , vsementsov@virtuozzo.com, "qemu-devel@nongnu.org Developers" , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/4/21 10:08 PM, Like Xu wrote: > Hi John, > > Thanks for your comment. > > On 2021/3/5 7:53, John Snow wrote: >> On 2/28/21 9:39 PM, Like Xu wrote: >>> Hi Genius, >>> >>> I am a user of QEMU v4.2.0 and stuck in an interesting bug, which may >>> still exist in the mainline. >>> Thanks in advance to heroes who can take a look and share understanding. >>> >> >> Do you have a test case that reproduces on 5.2? It'd be nice to know >> if it was still a problem in the latest source tree or not. > > We narrowed down the source of the bug, which basically came from > the following qmp usage: > > {'execute': 'human-monitor-command', 'arguments':{ 'command-line': > 'drive_del replication0' } } > > One of the test cases is the COLO usage (docs/colo-proxy.txt). > > This issue is sporadic,the probability may be 1/15 for a io-heavy guest. > > I believe it's reproducible on 5.2 and the latest tree. > Can you please test and confirm that this is the case, and then file a bug report on the LP: https://launchpad.net/qemu and include: - The exact commit you used (current origin/master debug build would be the most ideal.) - Which QEMU binary you are using (qemu-system-x86_64?) - The shortest command line you are aware of that reproduces the problem - The host OS and kernel version - An updated call trace - Any relevant commands issued prior to the one that caused the hang; or detailed reproduction steps if possible. Thanks, --js