On Thu, Oct 23, 2014 at 10:21 AM, Evgenii Smirnov <evgenii.smirnov@xxxxxxxxxxxxxxxx> wrote: > 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? Interesting. I guess it would be useful to look at perf top / and or get a perf report with "perf report -a -g" when running your high PPS workload, and see where the time is wasted. - R. -- 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
