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Commit f18f97ac authored by Marcin Nowakowski's avatar Marcin Nowakowski Committed by Steven Rostedt
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tracing/kprobes: Add a helper method to return number of probe hits 

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.

Link: http://lkml.kernel.org/r/1481293178-3128-1-git-send-email-marcin.nowakowski@imgtec.com



Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarMarcin Nowakowski <marcin.nowakowski@imgtec.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 99e6f6e8

kernel/trace/trace_kprobe.c

+13 −6
Original line number Diff line number Diff line
@@ -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;