Re: Patch question (Hyper-Threading support)

[Elizeu Santos-Neto <elizeu@cs.uchicago.edu>]

	Hi Keir,

	Thanks for the answer.

	Possibly I used an out of date Xen-3.0.testing source code.  

	What I meant by HT support was the construction of sibling maps by the
Guest OS smp-kernel using information about the core ids from the VCPU. 

	More precisely, I've found the following comment in the file:

	./linux-2.6-xen-sparse/arch/xen/kernel/smpboot.c

	 /* Currently, Xen gives no dynamic NUMA/HT info. */

	Thus, I modified this file and a couple of other to allow the guest os
kernel to build the siblings map properly.

	Regards,
	Eli
	
On Tue, 2006-03-28 at 08:32 +0100, Keir Fraser wrote:
> On 28 Mar 2006, at 01:52, Elizeu Santos-Neto wrote:
> 
> > 	Well, based on some quick inspections on the that I checked out from
> > the mercurial repository this afternoon, it seems that the HT support
> > has been already implemented. :-)
> >
> > 	Thus, here is a suggestion, it would be nice to make more details
> > available about who is doing what and in which phase of development
> > things are, this information could avoid duplicated efforts.
> 
> HT has been supported for years, so its development hasn't overlapped 
> with your own work. The existing support isn't very HT aware though. 
> For example, the schedulers treat HT pairs just the same as two 
> separate physical processors, so there may be more performance to be 
> had by making Xen a bit smarter.
> 
>   -- Keir
> 
>