This is used to calculate more accurate interval between two
calls of bdev_get_iostat RPC.
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Ib561b056bc8095aa23d04cb5f9ae6f558b157124
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/475167
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: GangCao <gang.cao@intel.com>