Re: [patch] jiffies wraparound [Re: 2.1.125 Show stopper list: Draft]

Rik van Riel (H.H.vanRiel@phys.uu.nl)
Fri, 23 Oct 1998 08:20:37 +0200 (CEST)

On Fri, 23 Oct 1998, Albert D. Cahalan wrote:
> Linus wrote:
> > On Fri, 23 Oct 1998, Albert D. Cahalan wrote:
>
> Do you plan to keep HZ==100 on Intel forever? Would that even include
> 64-bit chips? Note that people will want to run 32-bit Linux software
> on 64-bit hardware. Unless you really want to keep that crappy value,
> you need a transition plan.

[SNIP]

> > In short: HZ is not variable. Neither is the coprocessor reset value.
> Whoa, STOP! The coprocessor reset value is part of the Linux personality
> on 32-bit Intel hardare. It would be easy to have a new personality
> with a new coprocessor reset value; old software would still work.
>
> The data in /proc is shared by all processes. It is much harder to
> support old software reading /proc.

For proc-reading stuff we can easily check their personality
(if current->personality == HZ_3k)
fake_hz();

Supporting different proc readouts is just as easy as
supporting different personalities. If you don't believe
me I could code up some example code for you...

Rik.
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| Linux memory management tour guide. H.H.vanRiel@phys.uu.nl |
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