Re: [patch 11/13] s390: instruction processing damage handling.

[Martin Schwidefsky]

On Fri, 2006-04-28 at 10:39 +0200, Heiko Carstens wrote:
> > > +++ linux-2.6-patched/drivers/s390/s390mach.c	2006-04-24 16:47:28.000000000 +0200
> > ...
> > > +#define MAX_IPD_TIME	(5 * 60 * 100 * 1000) /* 5 minutes */
> > 
> > I'm no s390 expert, but shouldn't the above use something like HZ?
> 
> Using HZ here feels just wrong to me. MAX_IPD_TIME has nothing to do with the
> timer frequency. In this case it's used to tell if there were 30 machine
> checks within the last 5 minutes (in a usec granularity). It's just by
> accident that this could be expressed using HZ.
> (5 * 60 * USEC_PER_SEC) would probably look better...

Using HZ would be wrong. The check that uses MAX_IPD_TIME compares it
against the result of a get_clock() call. That uses the TOD Clock
directly, there is no dependency on HZ.

-- 
blue skies,
  Martin.

Martin Schwidefsky
Linux for zSeries Development & Services
IBM Deutschland Entwicklung GmbH

"Reality continues to ruin my life." - Calvin.


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