From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754012Ab1AZSEm (ORCPT <rfc822;w@1wt.eu>);
	Wed, 26 Jan 2011 13:04:42 -0500
Received: from mail-bw0-f46.google.com ([209.85.214.46]:63692 "EHLO
	mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753971Ab1AZSEY (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 26 Jan 2011 13:04:24 -0500
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=date:from:to:cc:subject:message-id:references:mime-version
         :content-type:content-disposition:in-reply-to:user-agent;
        b=FfHxzFU7qY2XiyDvkkaD7G1JUH4LJBd9zCVbxEI3WpDzLs2Z/7UzRlIgf1gzlhn5Kp
         68AUoBXG0aqrBw5/gRxznaRFowE2s5EVhAbZaMwfhr7ww1o1b2uDx/dbkj+P48zQUZ8P
         fL510NtcuX9YfdjBadqBjj6RiGmz98TQjC1rA=
Date: Wed, 26 Jan 2011 18:32:43 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-hotplug@vger.kernel.org,
        rostedt@goodmis.org, amit.kucheria@linaro.org
Subject: Re: [PATCH 2/2] tracing, perf : add cpu hotplug trace events
Message-ID: <20110126173241.GD1757@nowhere>
References: <AANLkTi=hQpCVJWZ_Op4mhnehufcBg2=h_=q4xXD66tGb@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <AANLkTi=hQpCVJWZ_Op4mhnehufcBg2=h_=q4xXD66tGb@mail.gmail.com>
User-Agent: Mutt/1.5.20 (2009-06-14)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Jan 25, 2011 at 09:54:59AM +0100, Vincent Guittot wrote:
> Please find below a new proposal for adding trace events for cpu hotplug.
> The goal is to measure the latency of each part (kernel, architecture)
> and also to trace the cpu hotplug activity with other power events. I
> have tested these traces events on an arm platform.
> 
> Subject: [PATCH 1/2] add cpu hotplug tracepoints
> 
> this patch adds new events for cpu hotplug tracing
>  * plug/unplug sequence
>  * core and architecture latency measurements
> 
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
>  kernel/cpu.c |   17 +++++++++++++++++
>  1 files changed, 17 insertions(+), 0 deletions(-)
> 
> diff --git a/kernel/cpu.c b/kernel/cpu.c
> index 156cc55..f04e9cf 100644
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -16,6 +16,9 @@
>  #include <linux/mutex.h>
>  #include <linux/gfp.h>
> 
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/cpu_hotplug.h>
> +
>  #ifdef CONFIG_SMP
>  /* Serializes the updates to cpu_online_mask, cpu_present_mask */
>  static DEFINE_MUTEX(cpu_add_remove_lock);
> @@ -200,7 +203,9 @@ static int __ref take_cpu_down(void *_param)
>  	int err;
> 
>  	/* Ensure this CPU doesn't handle any more interrupts. */
> +	trace_cpu_hotplug_arch_disable_start((unsigned int)(param->hcpu));
>  	err = __cpu_disable();
> +	trace_cpu_hotplug_arch_disable_end((unsigned int)(param->hcpu));

You should create a cpu var instead of doing that not very beautiful cast
twice.

Probably we should eventually rename arch_disable into just disable.

And same for die, because otherwise the name is quite long.

Other than that, looks all good to me.

Thanks.