Re: [PATCH 1/1] cpumask: force nr_cpumask_bit to NR_CPUS for CPUMASK_OFFSTACK=n

From: Rusty Russell
Date: Sat Dec 13 2008 - 04:55:26 EST


On Friday 12 December 2008 07:14:09 Mike Travis wrote:
> Re: cpumask conversions, or not?
>
> Rusty Russell wrote:
> > On Tuesday 09 December 2008 21:26:36 Mike Travis wrote:
> >> Rusty Russell wrote:
> >>> Hi all,
> >>>
> >>> The new cpumask conversions are going well, but unfortunately Stephen
> >>> uncovered a nasty bug via linux-next: the new cpumask operators only go to
> >>> nr_cpumask_bits which can be less than NR_CPUS if NR_CPUS > BITS_PER_LONG.
> >>> The undefined bits confuse the old cpumask operators. We fixed one case,
> >>> but I am concerned that we will break archs as we convert more core code.
> >> Hi Rusty,
> >>
> >> I think we can avoid this problem if we make cpumask_bits == NR_CPUS iff
> >> CONFIG_CPUMASK_OFFSTACK=n. This complies with the current cpumask_t
> >> approach and should cause all cpumask operators to always operate on
> >> all cpumask bits.
> >
> > A very good point. And it's no worse than the old method.
> >
> > OK, forget about this for now, no urgent conversions needed :)
> > Rusty.
>
> This probably should be submitted through linux-next for wider test coverage?

Identical patch already in series.

Thanks,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/