Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933406AbcLIOTo (ORCPT ); Fri, 9 Dec 2016 09:19:44 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:35492 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932299AbcLIOTn (ORCPT ); Fri, 9 Dec 2016 09:19:43 -0500 From: Marcin Nowakowski To: Steven Rostedt , Ingo Molnar CC: Subject: [PATCH v2 1/2] tracing/kprobes: add a helper method to return number of probe hits Date: Fri, 9 Dec 2016 15:19:37 +0100 Message-ID: <1481293178-3128-1-git-send-email-marcin.nowakowski@imgtec.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.80.2.5] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1664 Lines: 55 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. Signed-off-by: Marcin Nowakowski --- 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