| Message ID | 149076491191.24574.9187877160820798843.stgit@devbox |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, Mar 29, 2017 at 7:22 AM, Masami Hiramatsu <mhiramat@kernel.org> wrote: > Show sum of probe and retprobe nmissed count in > kprobe_profile, since retprobe can be missed even > if the kprobe itself succeeeded. > This explains user why their return probe didn't hit > sometimes. > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> I tested this patch with my kretprobe on "inet_csk_accept" when there are many processes waiting in the accept() syscall. I can now successfully see the nmissed counter in /sys/kernel/debug/tracing/kprobe_profile being incremented when the kretprobe is missed. Tested-by: Alban Crequy <alban@kinvolk.io> > --- > kernel/trace/trace_kprobe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 013f4e7..bbdc3de 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -896,7 +896,7 @@ static int probes_profile_seq_show(struct seq_file *m, void *v) > seq_printf(m, " %-44s %15lu %15lu\n", > trace_event_name(&tk->tp.call), > trace_kprobe_nhit(tk), > - tk->rp.kp.nmissed); > + tk->rp.kp.nmissed + tk->rp.nmissed); > > return 0; > } >
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 013f4e7..bbdc3de 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -896,7 +896,7 @@ static int probes_profile_seq_show(struct seq_file *m, void *v) seq_printf(m, " %-44s %15lu %15lu\n", trace_event_name(&tk->tp.call), trace_kprobe_nhit(tk), - tk->rp.kp.nmissed); + tk->rp.kp.nmissed + tk->rp.nmissed); return 0; }
Show sum of probe and retprobe nmissed count in kprobe_profile, since retprobe can be missed even if the kprobe itself succeeeded. This explains user why their return probe didn't hit sometimes. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- kernel/trace/trace_kprobe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)