Use the new spdk_ioat_flush interface to batch
doorbell writes - this significantly improves
descriptor throughput. For now, just set the
threshold for writing the descriptor to half of
the queue depth. We can always modify this later
to allow very specific thresholds, but for now
this simple change is sufficient.
Increases 512B descriptor throughput at QD=256 from
3.7M/s to 14.0M/s on my Skylake Xeon server.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I4504579e23cee5b6a1044849c49d33d58bdb51a9
Reviewed-on: https://review.gerrithub.io/c/445355
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
6728c1b8cb