Messages in this thread | | | Date | Tue, 13 Dec 2016 10:30:20 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2 1/2] tracing/kprobes: add a helper method to return number of probe hits |
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Hello Marcin,
On Fri, 9 Dec 2016 15:19:37 +0100 Marcin Nowakowski <marcin.nowakowski@imgtec.com> wrote:
> The number of probe hits is stored in a percpu variable and therefore > can't be read directly. Add a helper method trace_kprobe_nhit() that > performs the required calculation. > > It will be used in a follow-up commit that changes kprobe selftests to > verify the number of probe hits.
Ah, that's nicer & neet :)
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Thanks!
> > Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> > --- > kernel/trace/trace_kprobe.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > v2: improved commit message as suggested by Steven Rostedt > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index eb6c9f1..a2af1bc 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -73,6 +73,17 @@ static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) > return !!strchr(trace_kprobe_symbol(tk), ':'); > } > > +static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) > +{ > + unsigned long nhit = 0; > + int cpu; > + > + for_each_possible_cpu(cpu) > + nhit += *per_cpu_ptr(tk->nhit, cpu); > + > + return nhit; > +} > + > static int register_kprobe_event(struct trace_kprobe *tk); > static int unregister_kprobe_event(struct trace_kprobe *tk); > > @@ -882,14 +893,10 @@ static const struct file_operations kprobe_events_ops = { > static int probes_profile_seq_show(struct seq_file *m, void *v) > { > struct trace_kprobe *tk = v; > - unsigned long nhit = 0; > - int cpu; > - > - for_each_possible_cpu(cpu) > - nhit += *per_cpu_ptr(tk->nhit, cpu); > > seq_printf(m, " %-44s %15lu %15lu\n", > - trace_event_name(&tk->tp.call), nhit, > + trace_event_name(&tk->tp.call), > + trace_kprobe_nhit(tk), > tk->rp.kp.nmissed); > > return 0; > -- > 2.7.4 >
-- Masami Hiramatsu <mhiramat@kernel.org>
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