linux-kernel - Re: [PATCH] x86/mcheck/therm_throt.c: Don't log power limit and package level thermal throttle event in mce log

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Date:	Tue, 6 Dec 2011 20:06:48 +0100
From:	Borislav Petkov <bp@...64.org>
To:	"Yu, Fenghua" <fenghua.yu@...el.com>
Cc:	"Luck, Tony" <tony.luck@...el.com>, H Peter Anvin <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"Brown, Len" <len.brown@...el.com>,
	linux-kernel <linux-kernel@...r.kernel.org>, x86 <x86@...nel.org>
Subject: Re: [PATCH] x86/mcheck/therm_throt.c: Don't log power limit and
 package level thermal throttle event in mce log

On Tue, Dec 06, 2011 at 09:48:41AM -0800, Yu, Fenghua wrote:

> The printk is one way to notify users about the power limit and
> thermal throttle. The printk only dumps the events in an interval
> (300*HZ).
>
> Another way is to count the events in
> /sys/devices/system/cpu/cpu#/thermal_throttle. In this way, kernel
> logs every interrupt on any cpu into respective counters. User
> application can poll the counters and get more accurate and timely
> information for the events.
>
> As explained in this patch, core level thermal throttle is still
> logged in mcelog for legacy reason after this patch is applied.

I can see all that. Still, I'm questioning the need for those printks. A
user application polling the counters is a much better solution, IMHO,
than spamming the logs. IOW, is there a strong reason to have this -
even ratelimited - information in the logs and unnerve users, or, would
it be better to collect this info somewhere queitly and present it only
when something requests it?

Thanks.

-- 
Regards/Gruss,
Boris.

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