From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762441AbYJKULv (ORCPT ); Sat, 11 Oct 2008 16:11:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760093AbYJKULm (ORCPT ); Sat, 11 Oct 2008 16:11:42 -0400 Received: from nf-out-0910.google.com ([64.233.182.184]:36386 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755056AbYJKULm (ORCPT ); Sat, 11 Oct 2008 16:11:42 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :content-type:content-transfer-encoding; b=vwX19VxwPl2AxtCCJ0eKPxus1CF+bq+1/zoL69yaUGfGOyg9coxNV0gd9IWqTthoR9 feAU9vTRVeE1dtIGEFyCZVdqgC8/dX4f3dcJ+8uvj0JyRAur3RIEKA6iTw6EdJGDJJPp LUO8Ss/J29kRzMkbpEL2dSCJDq0vopJSkZDuQ= Message-ID: <48F10878.9080705@gmail.com> Date: Sat, 11 Oct 2008 22:11:36 +0200 From: Frederic Weisbecker User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Ingo Molnar CC: linux-kernel@vger.kernel.org, Steven Rostedt Subject: [PATCH 1/5] tracing/ftrace: Types and naming corrections for sched tracer Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch applies some corrections suggested by Steven Rostedt. Change the type of shed_ref into int since it is used into a Mutex, we don't need it anymore as an atomic variable in the sched_switch tracer. Also change the name of the register mutex. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt --- kernel/trace/trace_sched_switch.c | 30 +++++++++++++----------------- 1 files changed, 13 insertions(+), 17 deletions(-) diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 9d7bdac..969953b 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -16,8 +16,8 @@ static struct trace_array *ctx_trace; static int __read_mostly tracer_enabled; -static atomic_t sched_ref; -static DEFINE_MUTEX(tracepoint_mutex); +static int sched_ref; +static DEFINE_MUTEX(sched_register_mutex); static void probe_sched_switch(struct rq *__rq, struct task_struct *prev, @@ -28,7 +28,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev, int cpu; int pc; - if (!atomic_read(&sched_ref)) + if (!sched_ref) return; tracing_record_cmdline(prev); @@ -124,26 +124,22 @@ static void tracing_sched_unregister(void) static void tracing_start_sched_switch(void) { - long ref; - - mutex_lock(&tracepoint_mutex); - tracer_enabled = 1; - ref = atomic_inc_return(&sched_ref); - if (ref == 1) + mutex_lock(&sched_register_mutex); + if (!(sched_ref++)) { + tracer_enabled = 1; tracing_sched_register(); - mutex_unlock(&tracepoint_mutex); + } + mutex_unlock(&sched_register_mutex); } static void tracing_stop_sched_switch(void) { - long ref; - - mutex_lock(&tracepoint_mutex); - tracer_enabled = 0; - ref = atomic_dec_and_test(&sched_ref); - if (ref) + mutex_lock(&sched_register_mutex); + if (!(--sched_ref)) { tracing_sched_unregister(); - mutex_unlock(&tracepoint_mutex); + tracer_enabled = 0; + } + mutex_unlock(&sched_register_mutex); } void tracing_start_cmdline_record(void)