From: John Snow <jsnow@redhat.com>
To: Kevin Wolf <kwolf@redhat.com>
Cc: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
Eduardo Habkost <ehabkost@redhat.com>,
qemu-block@nongnu.org, qemu-devel <qemu-devel@nongnu.org>,
Hanna Reitz <hreitz@redhat.com>, Cleber Rosa <crosa@redhat.com>
Subject: Re: [PATCH v5 6/8] iotests/300: avoid abnormal shutdown race condition
Date: Wed, 27 Oct 2021 13:55:37 -0400 [thread overview]
Message-ID: <CAFn=p-Z2MiL5B3HQt9bXaeB4SuXVNYVOMu_WLzWrsFWgYSaoDQ@mail.gmail.com> (raw)
In-Reply-To: <YXlMjhokWt5R2cQf@redhat.com>
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On Wed, Oct 27, 2021 at 8:56 AM Kevin Wolf <kwolf@redhat.com> wrote:
> Am 26.10.2021 um 19:56 hat John Snow geschrieben:
> > Wait for the destination VM to close itself instead of racing to shut it
> > down first, which produces different error log messages from AQMP
> > depending on precisely when we tried to shut it down.
> >
> > (For example: We may try to issue 'quit' immediately prior to the target
> > VM closing its QMP socket, which will cause an ECONNRESET error to be
> > logged. Waiting for the VM to exit itself avoids the race on shutdown
> > behavior.)
> >
> > Reported-by: Hanna Reitz <hreitz@redhat.com>
> > Signed-off-by: John Snow <jsnow@redhat.com>
>
> I think this will still expose the race I described in my comment on
> patch 2.
>
> Kevin
>
>
I wrote a long, meandering explanation of how I think things work in reply
to that comment. TLDR: I didn't see the problem.
Here in reply to this comment I'll just ask: what exactly *is* the race you
see happening here even with this patch? I'm not sure I see it.
--js
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next prev parent reply other threads:[~2021-10-27 17:57 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-26 17:56 [PATCH v5 0/8] Switch iotests to using Async QMP John Snow
2021-10-26 17:56 ` [PATCH v5 1/8] python/machine: remove has_quit argument John Snow
2021-10-26 17:56 ` [PATCH v5 2/8] python/machine: Handle QMP errors on close more meticulously John Snow
2021-10-27 11:19 ` Kevin Wolf
2021-10-27 17:49 ` John Snow
2021-10-28 10:01 ` Kevin Wolf
2021-10-28 15:35 ` John Snow
2021-10-26 17:56 ` [PATCH v5 3/8] python/aqmp: Remove scary message John Snow
2021-10-26 17:56 ` [PATCH v5 4/8] iotests: Accommodate async QMP Exception classes John Snow
2021-10-26 17:56 ` [PATCH v5 5/8] iotests: Conditionally silence certain AQMP errors John Snow
2021-10-26 17:56 ` [PATCH v5 6/8] iotests/300: avoid abnormal shutdown race condition John Snow
2021-10-27 12:56 ` Kevin Wolf
2021-10-27 17:55 ` John Snow [this message]
2021-10-26 17:56 ` [PATCH v5 7/8] python/aqmp: Create sync QMP wrapper for iotests John Snow
2021-10-26 17:56 ` [PATCH v5 8/8] python, iotests: replace qmp with aqmp John Snow
2021-10-28 10:37 ` [PATCH v5 0/8] Switch iotests to using Async QMP Kevin Wolf
2021-10-28 14:48 ` John Snow
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