From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752885Ab3CRItW (ORCPT ); Mon, 18 Mar 2013 04:49:22 -0400 Received: from mail-ea0-f172.google.com ([209.85.215.172]:35153 "EHLO mail-ea0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649Ab3CRItT (ORCPT ); Mon, 18 Mar 2013 04:49:19 -0400 Date: Mon, 18 Mar 2013 09:49:13 +0100 From: Ingo Molnar To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Andrew Morton , Frederic Weisbecker Subject: Re: [PATCH 0/3 v2] [GIT PULL][3.9] tracing: Fixes with flags and latency tracers Message-ID: <20130318084913.GD17959@gmail.com> References: <20130315050616.512983245@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130315050616.512983245@goodmis.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > > Ingo, > > Here's take two of the last patch series I sent. The only difference > with this series is that I encapsulate the max_tr reference with > the #ifdef CONFIG_TRACER_MAX_TRACE. Other than that, it's the same. > > Here's the recap: > > The first patch fixes a long standing bug where the changing of > the trace options has absolutely no protection against multiple > changers. Luckily, this is something that requires human (root) > action, and is usually performed by a single individual. But as > scripts are starting to become more active, this bug is bound to > be triggered. > > The second patch is a bug where the setting of the overwrite flag > can cause the max and normal buffers to get out of sync. This > is more predomitinant with the 3.9 snapshot feature, but still > has an affect on the latency tracers. Which bring us to the third > patch. > > The third patch I found out that disabling overwrite to the buffers > screws with the latency tracers. If the buffer is in produce consumer > mode, the irqsoff tracer and friends wont show any output at all. > This was a bit frustrating to figure out. > > Hopefully this time it's good. > > Thanks, > > -- Steve > > Please pull the latest tip/perf/urgent-2 tree, which can be found at: > > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git > tip/perf/urgent-2 > > Head SHA1: 613f04a0f51e6e68ac6fe571ab79da3c0a5eb4da > > > Steven Rostedt (Red Hat) (3): > tracing: Protect tracer flags with trace_types_lock > tracing: Keep overwrite in sync between regular and snapshot buffers > tracing: Prevent buffer overwrite disabled for latency tracers > > ---- > kernel/trace/trace.c | 56 +++++++++++++++++++++++++++++-------- > kernel/trace/trace.h | 6 ++++ > kernel/trace/trace_irqsoff.c | 19 +++++++++---- > kernel/trace/trace_sched_wakeup.c | 18 ++++++++---- > 4 files changed, 78 insertions(+), 21 deletions(-) Pulled, thanks Steve! Ingo