From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753445Ab0FXGif (ORCPT ); Thu, 24 Jun 2010 02:38:35 -0400 Received: from mga11.intel.com ([192.55.52.93]:32964 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398Ab0FXGid (ORCPT ); Thu, 24 Jun 2010 02:38:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.53,472,1272870000"; d="scan'208";a="579408130" Date: Thu, 24 Jun 2010 14:38:29 +0800 From: Wu Fengguang To: Peter Zijlstra Cc: LKML , Frederic Weisbecker , Steven Rostedt Subject: Re: perf regression: failed to stat syscalls events Message-ID: <20100624063829.GA6501@localhost> References: <20100624013915.GA16965@localhost> <20100624014422.GA17476@localhost> <1277359125.1875.828.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1277359125.1875.828.camel@laptop> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 24, 2010 at 01:58:45PM +0800, Peter Zijlstra wrote: > On Thu, 2010-06-24 at 09:44 +0800, Wu Fengguang wrote: > > On Thu, Jun 24, 2010 at 09:39:15AM +0800, Wu Fengguang wrote: > > > Greetings, > > > > > > I noticed that > > > > > > # perf stat -e syscalls:sys_enter_mmap true > > > > > > refuse to work on 2.6.35-rc1. The last working kernel is 2.6.34. > > > > Other events like lock:* or block:* or whatever continue to work. > > So this is a problem specific to syscalls:*. > > Does your tree contain: Thanks, it worked! This patch is missing from linux-2.6.git for now. Thanks, Fengguang > --- > commit a8fb2608053547bc3152ea61a5ec7cdfce5d942c > Author: Steven Rostedt > Date: Thu Jun 10 14:53:16 2010 -0400 > > perf/tracing: Fix regression of perf losing kprobe events > > With the addition of the code to shrink the kernel tracepoint > infrastructure, we lost kprobes being traced by perf. The reason > is that I tested if the "tp_event->class->perf_probe" existed before > enabling it. This prevents "ftrace only" events (like the function > trace events) from being enabled by perf. > > Unfortunately, kprobe events do not use perf_probe. This causes > kprobes to be missed by perf. To fix this, we add the test to > see if "tp_event->class->reg" exists as well as perf_probe. > > Normal trace events have only "perf_probe" but no "reg" function, > and kprobes and syscalls have the "reg" but no "perf_probe". > The ftrace unique events do not have either, so this is a valid > test. If a kprobe or syscall is not to be probed by perf, the > "reg" function is called anyway, and will return a failure and > prevent perf from probing it. > > Reported-by: Srikar Dronamraju > Tested-by: Srikar Dronamraju > Acked-by: Peter Zijlstra > Signed-off-by: Steven Rostedt > > diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c > index e6f6588..8a2b73f 100644 > --- a/kernel/trace/trace_event_perf.c > +++ b/kernel/trace/trace_event_perf.c > @@ -96,7 +96,9 @@ int perf_trace_init(struct perf_event *p_event) > mutex_lock(&event_mutex); > list_for_each_entry(tp_event, &ftrace_events, list) { > if (tp_event->event.type == event_id && > - tp_event->class && tp_event->class->perf_probe && > + tp_event->class && > + (tp_event->class->perf_probe || > + tp_event->class->reg) && > try_module_get(tp_event->mod)) { > ret = perf_trace_event_init(tp_event, p_event); > break; >