Re: delay_tsc(): inefficient delay loop (2.6.16-mm1)

[Andreas Mohr]

Hi,

On Fri, Mar 24, 2006 at 09:22:51AM -0800, Ray Lee wrote:
> On 3/24/06, Andreas Mohr <andi@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > +       loops += bclock;
> [...]
> > -       } while ((now-bclock) < loops);
> > +       } while (now < loops);
> 
> Erm, aren't you introducing an overflow problem here?
> 
> if loops is 2^32-1, bclock is 1, the old version would execute the
> proper number of times, the new one will blow out in one tick.

Doh. That's what happens if you get too excited about some new trick...
Back to the drawing board, methinks.

Andreas Mohr

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