Hello, I am trying to achieve high packet per second throughput with 2-byte messages over Infiniband from kernel using IB_SEND verb. The most I can get so far is 3.5 Mpps. However, ib_send_bw utility from perftest package is able to send 2-byte packets with rate of 9 Mpps. After some profiling I found that execution of ib_post_send function in kernel takes about 213 ns in average, for the user-space function ibv_post_send takes only about 57 ns. As I understand, these functions do almost same operations. The work request fields and queue pair parameters are also the same. Why do they have such big difference in execution times? I'm using: Debian Jessie kernel 3.16-2-amd64 libibverbs1 (1.1.8-1) libmlx4-1 (1.0.6-1) perftest (2.3+0.12.gcb5b746-1) ConnectX-3 VPI adapter MT_1090110018 fw_ver: 2.32.5100 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
