On Wed, Mar 30, 2005 at 11:08:31AM +0200, Michael S. Tsirkin wrote: > Quoting r. Grant Grundler <[EMAIL PROTECTED]>: > > FWIW, default IPoIB perf is pathetic: ~1.5-1.6Gb/s > > with the above netperf command line. > > I think these systems have IOMMU, do they not?
They do. But HP ZX1 chipset allows 64-bit devices to bypass the IOMMU and directly address memory. tg3 is a 64-bit device and bypasses the IOMMU. ie tg3 is using physical addresses. > If so, could the fact that IPoIB calls dma_map_single for each > packet be the reason it is slow? Maybe dma_map_single is slow? pfmon output I've collected in the past doesn't support that theory. The ia64 "machvec" indirect function call certainly isn't helping though. ZX1 is about 3yr old chipset. I expect current x86/amd64 chipsets are not as old. I really need to collect PCI bus traces to verify if it's a chipset problem though. The logistics of doing that are non-trivial and I'll need help from a local HW group. *sigh* thanks, grant _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
