Re: [PATCH REPOST for 2.6.25] Use an own random generator forpageattr-test.c

From: Thomas Gleixner
Date: Tue Mar 11 2008 - 07:42:18 EST




On Tue, 11 Mar 2008, Andi Kleen wrote:

> On Tue, Mar 11, 2008 at 09:25:21AM +0100, Thomas Gleixner wrote:
> > On Tue, 11 Mar 2008, Andi Kleen wrote:
> > > Use an own random generator for pageattr-test.c
> > >
> > > [Repost. Please ack/nack. This is a bug fix and imho a .25 late merge
> > > candidate because it fixes a subtle bug]
> >
> > Care to point out which "subtle bug" is fixed ?
> >
> > You replace a random generator by another to get repeateable
> > sequences. The non repeatability of the cpa test patterns is hardly a
> > "subtle bug".
>
> The subtle bug(s) are first that it is not repeatable (it really should),

As I said before. It's hardly a bug. In fact it is questionable
whether fully reproducible test patterns are desired.

> then that it only initializes the CPU where the code first runs
> (since srandom32 is per CPU) and later might change CPUs and then that it
> adds totally unnecessary state bits to CPU #0 (or whatever runs first).

Can you please elaborate why changing the seed of the random generator
is a bug ? Networking reseeds the random generator itself, so what ?

Thanks,
tglx
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