2009/8/3 Vladislav Bolkhovitin <vst@xxxxxxxx>: > Ronald Moesbergen, on 08/03/2009 01:15 PM wrote: >> >> 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 > > And with client cfq, server noop? 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 cfq) blocksize R R R R(avg, R(std R (bytes) (s) (s) (s) MB/s) ,MB/s) (IOPS) 67108864 16.019 16.434 15.730 63.777 1.144 0.997 33554432 16.020 16.624 15.936 63.258 1.183 1.977 16777216 15.966 15.465 16.115 64.630 1.145 4.039 With two threads: 5) client: default, server: default (server noop, client cfq) blocksize R R R R(avg, R(std R (bytes) (s) (s) (s) MB/s) ,MB/s) (IOPS) 67108864 16.504 15.762 14.842 65.335 2.848 1.021 33554432 16.080 16.627 15.766 63.406 1.386 1.981 16777216 15.489 16.627 16.043 63.842 1.846 3.990 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
