Re: Re: [PATCH 1/6][RESEND] xen: Add NUMA support to Xen

[Ryan Harper <ryanh@us.ibm.com>]

* Keir Fraser <Keir.Fraser@cl.cam.ac.uk> [2006-05-15 11:55]:
> 
> On 15 May 2006, at 17:27, Andi Kleen wrote:
> 
> >>  1. You re-indented. Normally a good thing but not for copies of
> >>Linux source files. Please edit them and maintain them in Linux style
> >>(inc. hard tabs) as it makes it easier to sync with Linux updates.
> >
> >What Linux updates? The i386 NUMA support is basically dead and
> >bitrots slowly (except perhaps on NUMAQ) Every half a year someone
> >uses it and finds it doesn't work, maybe even fixes it and then it
> >breaks shortly after again. That's because it isn't used and tested in
> >any significant way. No distribution I'm aware of uses it either.
> >
> >If you want maintained NUMA it would be much better to base on the 
> >x86-64
> >NUMA code.
> 
> Sounds like an excellent plan to me: the x86/64 code looks cleaner too. 
> Let's go with the x86/64 code then, unless there are any objections 
> from the IBM folks?

When I looked at the x86_64 NUMA code, I noticed that SRAT parsing was
done by ACPI_NUMA (drivers/acpi/numa.c).  That code requires more ACPI
support than Xen currently has available.  Rather than pulling in all of
that ACPI, I chose to start with the i386 SRAT table parser which was
sufficient for both i386 and x86_64.  I would think that using the
modified i386 srat.c for parser gets the job done without bringing in
all of the support needed to compile drivers/acpi/numa.c in Xen.

How about putting the two together: use the i386 SRAT parser and the
x86_64 srat.c for structures and initialization?

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
(512) 838-9253   T/L: 678-9253
ryanh@us.ibm.com