From: "Michael R. Hines" <mrhines@linux.vnet.ibm.com>
To: Frank Yang <frank.yangjie@gmail.com>
Cc: Isaku Yamahata <yamahata@private.email.ne.jp>,
qemu-stable@nongnu.org, qemu-devel@nongnu.org,
yamahata@valinux.co.jp, Michael R Hines <mrhines@us.ibm.com>,
pbonzini@redhat.com
Subject: Re: [Qemu-devel] [Qemu-stable][PATCH] rdma: fix multiple VMs parallel migration
Date: Tue, 03 Sep 2013 10:13:54 -0400 [thread overview]
Message-ID: <5225EEA2.4060908@linux.vnet.ibm.com> (raw)
In-Reply-To: <CAO0YQGKOOtghkz8e4+d4sS_Y9bJoQfYpASAKx7YgWq5E6M7mrw@mail.gmail.com>
No top-posting, please.
On 09/03/2013 12:20 AM, Frank Yang wrote:
> Yes, it depends on low-level implementation. During my earlier test,
> using one CQ to send and receive may cause packet loss with heavy load:
> the destination thinks it send READY message successfully but the source
> still waits for it. This situation always happens when the destination
> polls
> receive CQE first.
>
> So I think using only one CQ may cause packet conflict or something
> like that,
> and it should be the driver bug. However, using two CQs fix the problem.
>
>
This doesn't seem like a very clear answer ..... are you sure its packet
loss?
The queue pairs are supposed to be reliable - I've never experienced a
situation
where packets were simply "dropped" for no reason without breaking the
connection and putting the QP into an error state.
- Michael
next prev parent reply other threads:[~2013-09-03 15:04 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-30 12:39 [Qemu-devel] [Qemu-stable][PATCH] rdma: fix multiple VMs parallel migration Frank Yang
2013-09-02 12:46 ` Isaku Yamahata
2013-09-03 4:20 ` Frank Yang
2013-09-03 5:38 ` Lei Li
2013-09-04 3:59 ` Frank Yang
2013-09-03 14:13 ` Michael R. Hines [this message]
2013-09-04 3:23 ` Frank Yang
2013-09-03 5:03 ` Lei Li
2013-09-04 2:42 ` Frank Yang
2013-09-04 8:10 ` Frank Yang
2013-09-24 17:59 ` [Qemu-devel] [Qemu-stable] [PATCH] " Michael R. Hines
2013-10-10 13:38 ` Frank Yang
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