From: Tim Bird <tim.bird@am.sony.com>
To: Tim Schmielau <tim@physik3.uni-rostock.de>
Cc: jesper.juhl@gmail.com, "Randy.Dunlap" <rdunlap@xenotime.net>,
linux-kernel@vger.kernel.org, Andrew Morton <akpm@osdl.org>
Subject: Re: early printk timings way off
Date: Fri, 16 Sep 2005 10:42:57 -0700 [thread overview]
Message-ID: <432B0421.3060807@am.sony.com> (raw)
In-Reply-To: <Pine.LNX.4.61.0509161920370.31820@gans.physik3.uni-rostock.de>
Tim Schmielau wrote:
> On Fri, 16 Sep 2005, Tim Schmielau wrote:
> The "Detected 1400.279 MHz processor." line just happens to be written
> _during_ time_init, when use_tsc is already set, but cycles_2_ns is not
> yet initialized.
That's exactly what I surmised as well. Our e-mails must
have crossed each other. :-)
> So I think everything is well-understood. It's just a matter of whether
> it's worth fixing.
Exactly. My own testing has focused on bootup time measurement.
Historically, the time spent before time_init() has been relatively
small and so I haven't (often) focused on trying to measure it
accurately. Although, I have done this on occasion to get
complete results.
Andrew's suggestion of a replaceable clock function would
satisfy me. What do other's think?
-- Tim
=============================
Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Electronics
=============================
next prev parent reply other threads:[~2005-09-16 17:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-15 21:42 early printk timings way off Jesper Juhl
2005-09-15 21:59 ` Randy.Dunlap
2005-09-15 22:07 ` Jesper Juhl
2005-09-15 22:37 ` Randy.Dunlap
2005-09-15 22:49 ` Jesper Juhl
2005-09-15 22:55 ` Randy.Dunlap
2005-09-15 23:00 ` Jesper Juhl
2005-09-16 10:30 ` Rogier Wolff
2005-09-16 13:55 ` Jesper Juhl
2005-09-16 17:04 ` Tim Bird
2005-09-16 17:15 ` Tim Schmielau
2005-09-16 17:25 ` Tim Schmielau
2005-09-16 17:42 ` Tim Bird [this message]
2005-09-16 18:24 ` Tony Luck
2005-09-16 17:37 ` Tim Bird
2005-09-16 10:09 ` Tim Schmielau
2005-09-16 10:33 ` Tim Schmielau
2005-09-16 13:56 ` Jesper Juhl
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