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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20111206190648.GB20445@aftab>
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.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/