Re: [rt-tests v2 v2 01/20] cyclictest: Always use libnuma

[John Kacur <jkacur@redhat.com>]

On Fri, 19 Feb 2021, Christian Eggers wrote:

> On Friday, 19 February 2021, 17:21:21 CET, John Kacur wrote:
> > 
> > On Fri, 19 Feb 2021, Daniel Wagner wrote:
> > 
> > > On Fri, Feb 19, 2021 at 04:21:46PM +0100, Christian Eggers wrote:
> > > > CONFIG_NUMA is not available on ARM32:
> > > 
> > > libnuma is not happy if the kernel doesn't have the config
> > > option. Well, in this case we just revert the patch I suppose.
> > > 
> > 
> > Yeah, I'm not happy with this.
> > To be sure Daniel did a lot of good work cleaning-up some of the numa 
> > calls and cleaning up the somewhat artificial smp / numa divide.
> > 
> > That work needs to continue, but I want the ability to build cyclictest
> > without NUMA, and that also means we need the small helpers.
> 
> Just for clarification: Does this mean that cyclictest shall link against
> libnuma (libnuma can be built on ARM without problems), but not call it
> functions at runtime?
> 
> From the numa.h:
> 
> /* NUMA support available. If this returns a negative value all other function
>    in this library are undefined. */
> int numa_available(void);
> 
> regards,
> Christian

We used to be able to build cyclictest without libnuma.
The small helpers that wrapped the calls to numa contained versions
without numa calls. Most people did have libnuma, so we were requiring 
libnuma say on x86_64.

I think at some point before Daniel starting removing the wrappers this
support was broken.

So, I mean the ability to build cyclitest without libnuma at least
on some architectures.

John