Re: [stable] cpumask: fix compat getaffinity

[Greg KH <greg@kroah.com>]

On Tue, May 11, 2010 at 10:47:03AM +0900, KOSAKI Motohiro wrote:
> > How's this?
> > 
> > cpumask: use nr_cpu_ids for printing and parsing cpumasks
> > 
> > Commit a45185d2d "cpumask: convert kernel/compat.c" broke
> > libnuma, which abuses sched_getaffinity to find out NR_CPUS
> > in order to parse /sys/devices/system/node/node*/cpumap.
> > 
> > However, the result now returned reflects nr_cpu_ids, and
> > cpumask_scnprintf et al. use nr_cpumask_bits which is NR_CPUS (for
> > CONFIG_CPUMASK_OFFSTACK=n) or nr_cpu_ids (for
> > CONFIG_CPUMASK_OFFSTACK=y).
> > 
> > We should use nr_cpu_ids consistently.
> >
> > Reported-by: Arnd Bergmann <arnd@arndb.de>
> > Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> > Cc: stable@kernel.org
> 
> Well, This patch seems to have ABI change. please don't send abi-change to -stable.

Why?  There is no such thing as a "stable" internal abi in the kernel,
and that includes the -stable kernel releases.

If it fixes a bug, that's all the requirement is.

> note: I'm not against this patch itself.

Great, then it should be just fine, right?

thanks,

greg k-h