[PATCH] glibc: Remove CPU set size checking from affinity functions [BZ #19143]

[Florian Weimer]

On 03/08/2016 08:42 PM, Michael Kerrisk (man-pages) wrote:

>> One caveat is that sched_getaffinity can set bits beyond the requested
>> allocation size (in bits) because the kernel gets a padded CPU vector
>> and sees a few additional bits.  
> 
> I'm not quite clear on this point. Does it get a padded CPU vector
> because CPU_ALLOC() might allocate a vector of size larger than the
> user requested?

Yes, this is the problem, combined with CPU_ALLOC_SIZE returning the
larger size (which is unavoidable).

This whole interface could have been designed much better (compare
select to epoll, for instance).

Florian