2009/7/31 Vladislav Bolkhovitin <vst@xxxxxxxx>: > > OK, as I expected, on the SCST level everything is clear and the forced > ordering change didn't change anything. > > But still, a single read stream must be the fastest from single thread. > Otherwise, there's something wrong somewhere in the I/O path: block layer, > RA, I/O scheduler. And, apparently, this is what we have and should find out > the cause. > > Can you check if noop on the target and/or initiator makes any difference? > Case 5 with 1 and 2 threads will be sufficient. That doesn't seem to help: client kernel: 2.6.26-15lenny3 (debian) server kernel: 2.6.29.5 with readahead-context, blk_run_backing_dev and io_context, forced_order With one IO thread: 5) client: default, server: default (server noop, client noop) blocksize R R R R(avg, R(std R (bytes) (s) (s) (s) MB/s) ,MB/s) (IOPS) 67108864 17.612 21.113 21.355 51.532 4.680 0.805 33554432 18.329 18.523 19.049 54.969 0.891 1.718 16777216 18.497 18.219 17.042 57.217 2.059 3.576 With two threads: 5) client: default, server: default (server noop, client noop) blocksize R R R R(avg, R(std R (bytes) (s) (s) (s) MB/s) ,MB/s) (IOPS) 67108864 17.436 18.376 20.493 54.807 3.634 0.856 33554432 17.466 16.980 18.261 58.337 1.740 1.823 16777216 18.222 17.567 18.077 57.045 0.901 3.565 Ronald. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
