On Sat, Oct 29, 2016 at 1:27 AM, William Tu via iovisor-dev < iovisor-dev@lists.iovisor.org> wrote:
> Hi, > > I'm trying to measure the performance of my BPF programs, which attach > to clsact. As a start, I thought I could simply measure the cycles > spent on cls_bpf_classify(), because it's the wrapper calling into my > BPF programs. > > However, it seems that kprobe can not probe cls_bpf_classify(), even > though cls_bpf_classify isn't in NOKPROBE_SYMBOL. Is there any reason > why we couldn't probe it? > > [root@vm-dev bpf]# echo 'p:myprobe3 cls_bpf_classify' >> > /sys/kernel/debug/tracing/kprobe_events > bash: echo: write error: No such file or directory > Worked for me: root@localhost:/sys/kernel/debug/tracing# echo 'p:myprobe3 cls_bpf_classify' > kprobe_events root@localhost:/sys/kernel/debug/tracing# cat events/kprobes/myprobe3/id 1256 > > As an alternative, I can probe on "__bpf_prog_run". > [root@vm-dev bpf]# echo 'p:myprobe4 __bpf_prog_run' >> > /sys/kernel/debug/tracing/kprobe_events > > Thanks > William > _______________________________________________ > iovisor-dev mailing list > iovisor-dev@lists.iovisor.org > https://lists.iovisor.org/mailman/listinfo/iovisor-dev >
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