Re: NUMA API observations

[Jesse Barnes <jbarnes@engr.sgi.com>]

> > > > My kernel is compiled with NR_CPUS=128, the setaffinity syscall must
> > > > be called with a bitmap at least as big as the kernels cpumask_t. I
> > > > will submit a patch for this shortly.
> > >
> > > Umm, what a misfeature. We size the buffer up to the biggest
> > > running CPU. That should be enough.
> > >
> > > IMHO that's just a kernel bug. How should a user space
> > > application sanely discover the cpumask_t size needed by the kernel?
> > > Whoever designed that was on crack.
> >
> > glibc now uses a select style interface. Unfortunately the interface has
> > changed about three times by now.
>
> I have no plans to track the glibc interface of the week for this
> and numactl must run with older glibc anyways, that is why I always
> used an own stub to this. I am not sure they even solved the problem
> completely. With the upcomming numactl version it should work.
>
> What I wonder is why IA64 worked though. We tested on it previously,
> but somehow didn't run into this. The regression test suite
> needs to check this better.

Yeah, I tested it with a kernel compiled for 512p, and didn't have any 
problems.  But that was awhile ago--I may have fixed the code and lost the 
diff when I sent you the other patches...

Jesse