[libvirt] [PATCH] util: assume modern CPU_ALLOC macros always exist

[Daniel P. Berrangé]

On Tue, Jul 09, 2019 at 05:10:59PM +0200, Martin Kletzander wrote:
> On Tue, Jul 09, 2019 at 12:33:54PM +0100, Daniel P. Berrangé wrote:
> > Support for the modern CPU_ALLOC macros was added 10 years ago in
> > 
> >  commit a73cd93b2428adbbc62bb919b6cf5ffd27728040
> >  Author: Daniel P. Berrange <berrange at redhat.com>
> >  Date:   Mon Nov 16 16:08:29 2009 +0000
> > 
> >    Alternate CPU affinity impl to cope with NR_CPUS > 1024
> > 
> > This is long enough that we can assume it always exists and drop the
> > back compat code.
> > 
> 
> Yes, it was added to glibc 12 years ago, so it should be in few distros now.
> I'm not sure what is the support in other libc implementations and what is our
> libc support matrix, but if we either:
> 
> a) support only glibc, or

We only test on glibc. We don't go out of our way to intentionally
break other libc impls so in general they can be expected to work.

> b) checked that other ones have that as well (ideally with a note in the commit
>    message)

I've not checked any other libcs, but if any don't support this after
12+ years they are seriously broken because they're unusable when the
kernel is built with large NR_CPUS. Thus I don't think we need to care
to check them. ie if they work, everything is fine, if they don't work
that they're unsupported targets for libvirt.

> then I can safely say:
> 
> Reviewed-by: Martin Kletzander <mkletzan at redhat.com>



Regards,
Daniel
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