RE: [Xen-devel] TPR write optimization (even improves 2003 sp2)

["James Harper" <james.harper@xxxxxxxxxxxxxxxx>]

> 
> For anyone who is interested, I have implemented TPR write
optimization
> based on Travis Betak's amdvopt driver. My implementation gets the
base
> address and length of hal.dll when loaded into memory and scans that
for
> patchable instructions, instead of the patch table approach that
Travis
> used.
> 
> A preliminary test under XP shows a 10x increase in iperf performance.
> 
> I'll test under 2003sp1 soon, unfortunately my sp1 decided to
> automatically install sp2 and I 'xm destroy'd it in the middle of that
> and now it's doing a chkdsk...
> 

2003sp1 iperf throughput went from 150mbit/second without the patch to
950mbit/second with the patch

Surprisingly, the AMD TPR write patch under 2003sp2 increases iperf
throughput from 1Gbit/second (without the patch) to 1.5Gbit/second
(patched). I guess this makes sense - 2003sp2 includes 'lazy write', but
the AMD patch optimises the write operation itself.

Is there such a facility available under Intel CPU's, other than the
latest 'flex priority' stuff which I am about to read up on?

Thanks

James


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