By now (5.1 is released), the Linux kernel initiator supports the
success optimization and further, the version that doesn't support
it (5.0) was EOL-ed. As such, lets open it up @ spdk by default.
Doing so provides a notable performance improvement: running perf with
iodepth of 64, randread, two threads and block size of 512 bytes for 60s
("-q 64 -w randread -o 512 -c 0x5000 -t 60") over the VMA socket acceleration
library and null backing store, we got 730K IOPS with the success
optimization vs 550K without it.
IOPS MiB/s Average min max
549274.10 268.20 232.99 93.23 3256354.96
728117.57 355.53 175.76 85.93 14632.16
To allow for interop with older kernel initiators, we added
a config knob under which the success optimization can be
enabled or disabled.
Change-Id: Ia4c79f607f82c3563523ae3e07a67eac95b56dbb
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/457644
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Ziye Yang <ziye.yang@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
6629202cbd