Re: [Xen-devel] Xen & I/O in clusters - Single Vs. Dual CPU issue

[Ian P. <Ian...@cl...>]

> But, in a dual CPU cluster, Intel Xenon CPU 2.40 GHz  Ethernet 
> controller: Intel Corp. 82547GI Gigabit Ethernet Controller, we get 
> only 1%
> (from 114 000 KB/s -> 110 000 KB/s) performance loss.)

Good, that's the result we expect.

> Hi, we have validated the single CPU results in another single CPU 
> cluster, and we still get an performance loss about 30%
> (ca. 85 000 KB/s between two dom0 nodes (and NOT 114 000 KB/s),
> Specs:
> Ethernet controller: Intel Corp. 82547GI Gigabit Ethernet Controller
> CPU: Intel(R) Pentium(R) 4 CPU 3.40GHz single CPU
> RAM: 1 GB)

Hmm, have your systems got an IOAPIC, or is Xen using the legacy
PIC code? The latter probably hasn't been thoroughly performance
tested...

Ian