From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932956AbdHYN4t (ORCPT ); Fri, 25 Aug 2017 09:56:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:52840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756286AbdHYN4r (ORCPT ); Fri, 25 Aug 2017 09:56:47 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E81321A6E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Fri, 25 Aug 2017 09:56:44 -0400 From: Steven Rostedt To: Zhou Chengming Cc: , , , , , , Subject: Re: [PATCH] perf/ftrace: fix doubled traces of perf on ftrace:function Message-ID: <20170825095644.5d310469@gandalf.local.home> In-Reply-To: <1503668977-12526-1-git-send-email-zhouchengming1@huawei.com> References: <1503668977-12526-1-git-send-email-zhouchengming1@huawei.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 25 Aug 2017 21:49:37 +0800 Zhou Chengming wrote: > When run perf on the ftrace:function tracepoint, there is a bug > which can be reproduced by: > > perf record -e ftrace:function -a sleep 20 & > perf record -e ftrace:function ls > perf script > > ls 10304 [005] 171.853235: ftrace:function: > perf_output_begin > ls 10304 [005] 171.853237: ftrace:function: > perf_output_begin > ls 10304 [005] 171.853239: ftrace:function: > task_tgid_nr_ns > ls 10304 [005] 171.853240: ftrace:function: > task_tgid_nr_ns > ls 10304 [005] 171.853242: ftrace:function: > __task_pid_nr_ns > ls 10304 [005] 171.853244: ftrace:function: > __task_pid_nr_ns > > We can see that all the function traces are doubled in perf.data > of "ls". > > The problem is caused by the inconsistency of the register > function perf_ftrace_event_register() with the probe function > perf_ftrace_function_call(). The former registers one probe > for every perf_event. And the latter handles all perf_events > on the current cpu. So when two perf_events on the current cpu, > the traces of them will be doubled. > > So this patch adds an extra parameter "event" for perf_tp_event, > only send sample data to this event when it's not NULL. > > Signed-off-by: Zhou Chengming > --- > include/linux/perf_event.h | 2 +- > include/linux/trace_events.h | 4 ++-- > kernel/events/core.c | 13 +++++++++---- > kernel/trace/trace_event_perf.c | 4 +++- > kernel/trace/trace_kprobe.c | 4 ++-- > kernel/trace/trace_syscalls.c | 4 ++-- > kernel/trace/trace_uprobe.c | 2 +- The trace files look fine to me. Acked-by: Steven Rostedt (VMware) -- Steve > 7 files changed, 20 insertions(+), 13 deletions(-) >