From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33459) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1boVOZ-00060m-4z for qemu-devel@nongnu.org; Mon, 26 Sep 2016 08:52:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1boVOU-0002o4-3A for qemu-devel@nongnu.org; Mon, 26 Sep 2016 08:52:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48854) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1boVOT-0002n3-SX for qemu-devel@nongnu.org; Mon, 26 Sep 2016 08:52:26 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B321FC05492D for ; Mon, 26 Sep 2016 12:52:24 +0000 (UTC) References: <20160923153612.GU3233@thinpad.lan.raisama.net> <20160923184040-mutt-send-email-mst@kernel.org> <29325c65-7ee6-22ed-31b3-211bcaceef50@redhat.com> <4f7bb8d9-a9da-5c06-a0b7-20dea8b802f8@redhat.com> <274086782.1698878.1474836953815.JavaMail.zimbra@redhat.com> <20160926121331.GF3877@thinpad.lan.raisama.net> From: Maxime Coquelin Message-ID: <3c623e89-3a46-d77b-c352-834da483531f@redhat.com> Date: Mon, 26 Sep 2016 14:52:21 +0200 MIME-Version: 1.0 In-Reply-To: <20160926121331.GF3877@thinpad.lan.raisama.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] vhost-user-test failure List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= Cc: "Michael S. Tsirkin" , qemu-devel@nongnu.org, =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= Hi, On 09/26/2016 02:13 PM, Eduardo Habkost wrote: > On Sun, Sep 25, 2016 at 04:55:53PM -0400, Marc-Andr=E9 Lureau wrote: >> Hi >> >> ----- Original Message ----- >>> This time with Marc-Andr=E9 in cc:... >>> >>> On 09/23/2016 07:40 PM, Maxime Coquelin wrote: >>>> >>>> >>>> On 09/23/2016 05:41 PM, Michael S. Tsirkin wrote: >>>>> On Fri, Sep 23, 2016 at 12:36:12PM -0300, Eduardo Habkost wrote: >>>>>> Hi, >>>>>> >>>>>> I hit a weird vhost-user-test failure on travis-ci recently, on a >>>>>> branch where I didn't touch any vhost-related code. From a quick >>>>>> look at the code, it looks like the vhost-user code is unhappy to >>>>>> see a disconnected socket. >>>>>> >>>>>> I wasn't able to reproduce it. It seems to be a hard to reproduce >>>>>> race between vhost-user code and socket reconnection. >>>>>> >>>>>> The failure can be seen at: >>>>>> >>>>>> https://travis-ci.org/ehabkost/qemu-hacks/jobs/162077239 >>>>> >>>>> Maxime looked at something similiar. Any idea? >>>> No, not really. >>>> Marc-Andr=E9 contributed a lot to these tests, I add him in cc: in c= ase >>>> he has an idea. >>>> >>>> I will have a look in the mean time. >>>> >> >> I am unable to reproduce locally (over 500x iterations), and I >> have no clue what's going on: the warnings there aren't the >> problem (that's the main reason why we use the subprocess, to >> silence those). Do you have a local reproducer or is it only on >> travis? Afaik, there are no other reports of this test failing, >> are you sure its not related to changes on your branch? > > I don't have a local reproducer, I could only see it once on > travis-ci. Maybe it is not possible to reproduce it if the > machine isn't loaded enough to make the right thread/process be > delayed. I'm also trying to reproduce it. Interestingly, launching the test with strace, I reproduce another problem systematically: $> strace -o /tmp/vut -ff ./tests/vhost-user-test /x86_64/vhost-user/read-guest-mem: OK /x86_64/vhost-user/migrate: Vhost user backend fails to broadcast fake RA= RP OK /x86_64/vhost-user/reconnect: OK I'll try to load the CPU randomly when executing the test. Regards, Maxime