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Date: Fri, 15 Nov 2002 17:17:37 +0100 (CET)
From: Tim Schmielau <tim@physik3.uni-rostock.de>
To: "Mario 'BitKoenig' Holbe" <Mario.Holbe@RZ.TU-Ilmenau.DE>
cc: <linux-kernel@vger.kernel.org>, <Elrond@Wunder-Nett.org>
Subject: Re: /proc/stat interface and 32bit jiffies / kernel_stat
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On Fri, 15 Nov 2002, Mario 'BitKoenig' Holbe wrote:

[system idle time will overflow after about 497/NR_CPUS days]
> 
> Since it should not be a big problem to fix this, to
> at least reduce the problem back to the 500 days
> jiffies-overflow problem, I'd suggest to do so.
> 
> No need to mention, that 64bit jiffies and statistics on
> all platforms at all would be great :)

2.5 has 64 bit jiffies (but not (yet?) 64 bit statistics).

A patch for 2.4 that fixes the overflow in proc_stat as well as 
introducing 63 bit jiffies is at
  http://www.physik3.uni-rostock.de/tim/kernel/2.4/jiffies64-20.patch.gz

> 
> Btw... Could anybody please explain me the problems to
> expect while a jiffies overflow? Would a kernel possibly
> survive this at all and if, what's the chance to? :)

"ps" will report processes started before the jiffies wrap as being 
started in the future, but this won't do any harm.

Tim

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