David Dillow wrote: >> if we look on the 50% for SAS/1M IOs that you're presenting, can you tell >> what made the difference, srp went from sg_tablesize of 255 to 256 so the >> upper layers where able to provide 1M as one IO
> This win is from sg_tablesize going from 255 to 256 in this case; the HW > really likes that better than getting two requests -- one for 1020 KB > and one for 4 KB. Its always nice to find the simplest explanation to the greatest improvement... going to the 2nd largest gains > SAS 2M 520 MB/s 861 MB/s > SAS 4M 529 MB/s 921 MB/s > SAS 8M 600 MB/s 951 MB/s I wonder what made the difference here? it can't be only the 255 --> 256 sg_tablesize change, for the 2M case the change to use 512 pages FMRs could let you use one rkey/fmr for the whole IO but not for 4M/8M Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
