Subject: Re: Faster Migration
To: Jed Davis <jdev@panix.com>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: port-xen
Date: 09/16/2005 20:15:27
On Thu, Sep 15, 2005 at 08:52:07PM -0400, Jed Davis wrote:
> Jed Davis <jdev@panix.com> writes:
> 
> > What I've been slowly leading up to: with this and the other three
> > changes I've posted about today, I can successfully (and consistently)
> > save and restore a Linux domU with a NetBSD dom0.
> 
> Live migration also works -- and non-live, for that matter.  (I have
> had a domain fail to suspend once, while running a process on the domU
> that repeatedly wrote to 2MB of memory, but I haven't been able to
> reproduce it, and it's likely not our problem anyway.)
> 
> But it's a bit slow, because xfrd reads from the network socket using
> fread() on an _IONBF'ed stream; under NetBSD, this results in a
> sequence of one-character reads.  This behavior, as far as I can tell,
> goes back all the way to V7 Unix; i.e., it's older than me.
> 
> So I've modified libxutil, which has its own IO indirection layer, to
> switch to read(2) in the "unbuffered" case; the patch is attached.

Thanks ! I've commited your patch to pkgsrc.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--