On Fri, 20 Jun 2008 09:49:29 am Mark Nelson wrote: > On Thu, 19 Jun 2008 09:53:16 pm Arnd Bergmann wrote: > > On Thursday 19 June 2008, Mark Nelson wrote: > > > The plan is to use Michael Ellerman's code patching work so that at > > > runtime > > > if we're running on a Cell machine the new routines are called but > > > otherwise > > > the existing memory copy routines are used. > > > > Have you tried running this code on other platforms to see if it > > actually performs worse on any of them? I would guess that the > > older code also doesn't work too well on Power 5 and Power 6, so the > > cell optimized version could give us a significant advantage as well, > > albeit less than another CPU specific version. > > > > Arnd <>< > > > > I did run the tests on Power 5 and Power 6, and on Power 5 with the > new routines, the iperf bandwidth increased to 7.9 GBits/sec up from > 7.5 GBits/sec; but on Power 6 the bandwidth with the old routines > was 13.6 GBits/sec compared to 12.8 GBits/sec...
After running the tests again I get a similar result, where on Power 6 the new routine is slower than the old one. I'll spend some time doing tests to see if we can come up with a routine that works well on Power 6 too. Mark _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev