> > with/without CONFIG_X86_PAT gives the same results... > I noted that I have CONFIG_MTRR=y so maybe this can explain the nice latency > even without setting X86_PAT?
I don't understand: your results below don't seem to have good results without X86_PAT? In any case I don't see how you can get the lowest latency (from WC mapping to userspace) without X86_PAT, since pgprot_writecombine() will fall back to pgprot_noncached() is X86_PAT=n. Anyway, thanks a lot for testing, I'll go ahead and include the patch in my next pull request. > 2.6.29 without CONFIG_X86_PAT > Latency typical: 1.43087 usec > Latency best : 1.41287 usec > > 2.6.29 + CONFIG_X86_PAT > Latency typical: 1.43245 usec > Latency best : 1.41295 usec > > 2.6.29 + CONFIG_X86_PAT + your patch > Latency typical: 1.14896 usec > Latency best : 1.12646 usec > > 2.6.29 + CONFIG_X86_PAT + ofed's patch > Latency typical: 1.14746 usec > Latency best : 1.12646 usec _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
