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From: Zoltan Kiss <zoltan.kiss@citrix.com>
To: xu cong <congxumail@gmail.com>, xen-devel@lists.xensource.com
Cc: wei.liu2@citrix.com, ian.campbell@citrix.com
Subject: Re: xen-netback in linux 3.12
Date: Mon, 20 Jan 2014 10:28:29 +0000	[thread overview]
Message-ID: <52DCFA4D.4070903@citrix.com> (raw)
In-Reply-To: <CA+hYhXtn_J5d=9JUU7qL5YVc4b2yqM9sonQX01cd=TPn--K02g@mail.gmail.com>

On 17/01/14 21:30, xu cong wrote:
> Hi all,
>
> I found xen-netback changed a lot in latest kernel. The shared
> xen-netback threads in driver domain is replaced by per-vif kernel
> thread. In my platform, I found the I/O throughput and scalability of
> per-vif netback is better than previous implementation. Another
> advantage is that I can use cgroups to control the CPU fair share among
> all VMs in driver domain (I group netback thread and blkback thread for
> each VM). Is there any other motivation for this modification? Thanks.

as far as I remember scalability was the only motivation. Previously you 
could end in a situation where one thread (pinned to a vCPU) did a lot 
of work while others nothing. In this thread-per-VIF model the kernel 
has the ability to schedule the workloads as it want, and users can also 
poke around with settings.

Zoli

      reply	other threads:[~2014-01-20 10:28 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-17 21:30 xen-netback in linux 3.12 xu cong
2014-01-20 10:28 ` Zoltan Kiss [this message]

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