From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: [RFC] Scheduler work,	part 1: High-level goals and
	interface.
Date: Fri, 10 Apr 2009 10:34:45 -0700
Message-ID: <49DF8335.7030501@goop.org>
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To: Ian Pratt <Ian.Pratt@eu.citrix.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>, "Tian,
	Kevin" <kevin.tian@intel.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
List-Id: xen-devel@lists.xenproject.org

Ian Pratt wrote:
>  1. explicitly present HT to guests and gang schedule threads
>
>  2. normal free-for-all with HT aware accounting.
>
> Of course, #1 isn't optimal if guests may migrate between HT and non-HT systems.
>   

Well, we could extend vcpu hotplug to deal with those kinds of cpu 
topology changes, but I guess that doesn't help most Windows/hvm 
guests.  But I think if those vcpus stop being siblings, I don't think 
it would hurt if we stopped gang scheduling them, so long as they're 
kept close (same package, I guess).

    J