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From: Stephen Boyd <sboyd@codeaurora.org>
To: Joe Perches <joe@perches.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nohz: remove "Switched to NOHz mode" debugging messages
Date: Tue, 23 Aug 2011 12:15:51 -0700	[thread overview]
Message-ID: <4E53FC67.7090108@codeaurora.org> (raw)
In-Reply-To: <1314126777.1659.2.camel@Joe-Laptop>

On 08/23/2011 12:12 PM, Joe Perches wrote:
> On Tue, 2011-08-23 at 13:20 +0200, Heiko Carstens wrote:
>> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>>
>> When performing cpu hotplug tests the kernel printk log buffer gets flooded
>> with pointless "Switched to NOHz mode..." messages. Especially when afterwards
>> analyzing a dump this might have removed more interesting stuff out of the
>> buffer.
>> Assuming that switching to NOHz mode simply works just remove the printk.
>> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> []
>> -
>> -	printk(KERN_INFO "Switched to NOHz mode on CPU #%d\n", smp_processor_id());
> Though I don't know if these are actually particularly
> useful messages, perhaps pr_info_ratelimited() might
> be appropriate instead.

Or perhaps a printk_once() would be good. Presumably the second switch
to NOHz mode wouldn't be as dangerous as the first.

-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.


  reply	other threads:[~2011-08-23 19:15 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-23 11:20 [PATCH] nohz: remove "Switched to NOHz mode" debugging messages Heiko Carstens
2011-08-23 19:12 ` Joe Perches
2011-08-23 19:15   ` Stephen Boyd [this message]
2011-08-24  5:52     ` Heiko Carstens
2011-08-23 22:36 ` David Miller

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