Eric Lee / smarc-fsl-linux-kernel

08 Apr, 2016

1 commit

  • e3edfdec0   samples/bpf: add tracepoint vs kprobe performance tests ... Browse Code ยป

    the first microbenchmark does
    fd=open("/proc/self/comm");
    for() {
    write(fd, "test");
    }
    and on 4 cpus in parallel:
    writes per sec
    base (no tracepoints, no kprobes) 930k
    with kprobe at __set_task_comm() 420k
    with tracepoint at task:task_rename 730k

    For kprobe + full bpf program manully fetches oldcomm, newcomm via bpf_probe_read.
    For tracepint bpf program does nothing, since arguments are copied by tracepoint.

    2nd microbenchmark does:
    fd=open("/dev/urandom");
    for() {
    read(fd, buf);
    }
    and on 4 cpus in parallel:
    reads per sec
    base (no tracepoints, no kprobes) 300k
    with kprobe at urandom_read() 279k
    with tracepoint at random:urandom_read 290k

    bpf progs attached to kprobe and tracepoint are noop.

    Signed-off-by: Alexei Starovoitov
    Signed-off-by: David S. Miller

    Alexei Starovoitov