linux-kernel - Re: [BUG] cpufreq: constant cpu

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: <20080825112244.34b2fe67@infradead.org>
Date:	Mon, 25 Aug 2008 11:22:44 -0700
From:	Arjan van de Ven <arjan@...radead.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Dave Jones <davej@...emonkey.org.uk>,
	Peter Zijlstra <peterz@...radead.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	cpufreq@...r.kernel.org, Alok Kataria <akataria@...are.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>
Subject: Re: [BUG] cpufreq: constant cpu_khz

On Mon, 25 Aug 2008 19:57:12 +0200
Ingo Molnar <mingo@...e.hu> wrote:

> 
> * Dave Jones <davej@...emonkey.org.uk> wrote:
> 
> >  > hm, that too is due to the tsc.c unification - Alok Cc:-ed.
> >  > Applied your fix to x86/urgent.
> > 
> > ACKed-by: Dave Jones <davej@...hat.com>
> > 
> > Good catch Peter.  I'm puzzled how that bug was latent on 64bit for
> > so long with no-one realising though.
> 
> i think it's the combination of these two factors:
> 
>  - bootup frequently is typically full-speed, so we calibrate things 
>    right
> 
>  - cpufreq events are relatively slow-scale - and when they trigger
> the system is definitely not under load. So how precisely the
> scheduler functions isnt all that important in such scenarios -
> there's tons of CPU power available.
> 

- many many of the 64 bit capable cpus are constant-tsc anyway

--
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/