From: Juan Quintela <quintela@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: qemu-devel@nongnu.org, "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 6/6] RFH: We lost "connect" events
Date: Mon, 19 Aug 2019 12:46:20 +0200 [thread overview]
Message-ID: <87pnl1301v.fsf@trasno.org> (raw)
In-Reply-To: <20190819095228.GC12960@redhat.com> ("Daniel P. =?utf-8?Q?Ber?= =?utf-8?Q?rang=C3=A9=22's?= message of "Mon, 19 Aug 2019 10:52:28 +0100")
Daniel P. Berrangé <berrange@redhat.com> wrote:
> On Wed, Aug 14, 2019 at 04:02:18AM +0200, Juan Quintela wrote:
>> When we have lots of channels, sometimes multifd migration fails
>> with the following error:
>>
>> Any good ideas?
>
> In inet_listen_saddr() we call
>
> if (!listen(slisten, 1)) {
>
> note the second parameter sets the socket backlog, which is the max
> number of pending socket connections we allow. My guess is that the
> target QEMU is not accepting incoming connections quickly enough and
> thus you hit the limit & the kernel starts dropping the incoming
> connections.
>
> As a quick test, just hack this code to pass a value of 100 and see
> if it makes your test reliable. If it does, then we'll need to figure
> out a nice way to handle backlog instead of hardcoding it at 1.
Nice.
With this change I can create 100 channels on a 4 core machine without
any trouble.
How can we proceed from here?
Thanks, Juan.
next prev parent reply other threads:[~2019-08-19 10:47 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 2:02 [Qemu-devel] [PATCH 0/6] Fix multifd with big number of channels Juan Quintela
2019-08-14 2:02 ` [Qemu-devel] [PATCH 1/6] migration: Add traces for multifd terminate threads Juan Quintela
2019-08-14 11:17 ` Dr. David Alan Gilbert
2019-08-19 11:14 ` Philippe Mathieu-Daudé
2019-08-14 2:02 ` [Qemu-devel] [PATCH 2/6] migration: Make global sem_sync semaphore by channel Juan Quintela
2019-08-14 14:34 ` Dr. David Alan Gilbert
2019-08-14 2:02 ` [Qemu-devel] [PATCH 3/6] migration: Make sure that all multifd channels have been created Juan Quintela
2019-08-14 14:58 ` Dr. David Alan Gilbert
2019-08-19 8:29 ` Juan Quintela
2019-08-14 2:02 ` [Qemu-devel] [PATCH 4/6] migration: Make multifd threads wait until all " Juan Quintela
2019-08-14 2:02 ` [Qemu-devel] [PATCH 5/6] migration: add some multifd traces Juan Quintela
2019-08-14 16:23 ` Dr. David Alan Gilbert
2019-08-19 11:10 ` Philippe Mathieu-Daudé
2019-08-19 11:13 ` Philippe Mathieu-Daudé
2019-08-14 2:02 ` [Qemu-devel] [PATCH 6/6] RFH: We lost "connect" events Juan Quintela
2019-08-19 9:52 ` Daniel P. Berrangé
2019-08-19 10:33 ` Juan Quintela
2019-08-19 10:40 ` Daniel P. Berrangé
2019-08-19 10:46 ` Juan Quintela [this message]
2019-08-19 10:49 ` Daniel P. Berrangé
2019-08-19 10:50 ` Juan Quintela
2019-08-19 11:00 ` Peter Maydell
2019-08-19 11:06 ` Daniel P. Berrangé
2019-08-19 10:47 ` Juan Quintela
2019-08-14 11:43 ` [Qemu-devel] [PATCH 0/6] Fix multifd with big number of channels no-reply
2019-08-14 14:53 ` Dr. David Alan Gilbert
2019-08-14 23:24 ` no-reply
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