From: Dominik Brodowski <linux@brodo.de>
To: john stultz <johnstul@us.ibm.com>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>,
lkml <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>
Subject: Re: Question: monolitic_clock, timer_{tsc,hpet} and CPUFREQ
Date: Sun, 7 Sep 2003 20:57:55 +0200 [thread overview]
Message-ID: <20030907185755.GA19923@brodo.de> (raw)
In-Reply-To: <1062749594.5809.7.camel@laptop.cornchips.homelinux.net>
On Fri, Sep 05, 2003 at 01:13:14AM -0700, john stultz wrote:
> On Thu, 2003-09-04 at 20:14, Dmitry Torokhov wrote:
> > I noticed that although timer_tsc registers cpufreq notifier to detect
> > frequency changes and adjust cpu_khz it does not set cyc2ns_scale. Is
> > monotonic clocks supposed to be also accurate?
>
> You are correct, without adjusting the cyc2ns_scale value
> monotonic_clock() will not be accurate on freq changing hardware.
Seems to be a necessary update. Thanks for noting this.
> Looks fine to me. Although I don't have any cpufreq enabled hardware, so
> I'm unable to test this (main cause I never added it myself).
/me has cpufreq enabled hardware -- but how can I accurately debug
monotonic_ticks()?
Dominik
next prev parent reply other threads:[~2003-09-07 19:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-09-05 3:14 Question: monolitic_clock, timer_{tsc,hpet} and CPUFREQ Dmitry Torokhov
2003-09-05 8:13 ` john stultz
2003-09-07 18:57 ` Dominik Brodowski [this message]
2003-09-08 17:30 ` john stultz
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