Re: [PATCH] sched: fix never executed code due to expression always false

[Nick Piggin <nickpiggin@yahoo.com.au>]

Jesper Juhl wrote:
> On Fri, 15 Apr 2005, Nick Piggin wrote:
>
>
> > Jesper Juhl wrote:
> >
> > > There are two expressions in kernel/sched.c that are always false since they
> > > test for <0 but the result of the expression is unsigned so they will never
> > > be less than zero. This patch implement the logic that I believe is intended
> > > without the signedness issue and without the nasty casts.
> > > <disclaimer>patch is compile tested only</disclaimer>
> > This is not *quite* the intended behaviour. It is OK for prev->timestamp
> > to be '0 - a bit' and now to be '0 + a bit' in the case of wrapping.
> >
> > Although considering they're 64-bit values, I'm not sure how much we care.
>
> How do you propose to fix this then?  As the code is now the expressionsa 
> are always false - should we just remove the them?  Or do you have a 
> sensible definition of "a bit" ?  or ome other suggestion alltogether?

Make it a signed comparison?

--
SUSE Labs, Novell Inc.

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