Re: cpumask: fix compat getaffinity

[Rusty Russell]

On Wed, 12 May 2010 06:00:45 pm Milton Miller wrote:
> 
> At least for parsing, we need to allocate and parse NR_CPUS until
> all places like arch/powerpc/platforms/pseries/xics.c that compare a
> user-supplied mask to CPUMASK_ALL are eliminated.

Good point.  Anton will want to fix those anyway for CONFIG_CPUMASK_OFFSTACK,
too, but that's the reason the parsing uses nr_cpumask_bits.

> > Would it make sense to use my initial patch for -stable, which reverts
> > the ABI back to before the change that caused the problem, but apply
> > the correct fix (changing the ABI throughout) for future releases?
> 
> This would definitly be the conservative fix.

Instead of changing back to NR_CPUS which will break libnuma for
CPUMASK_OFFSTACK, how about changing it to nr_cpumask_bits and having an
explicit comment above it:

	/* libnuma assumes we match scnprintf for /sys/.../node/node*/cpumap */

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/