Re: [PATCH v5 0/2] Balanced allocation of hugepages

[Thomas Monjalon <thomas@monjalon.net>]

21/06/2017 10:41, Jerin Jacob:
> > > 1. There are many machines (arm/ppc), which do not support NUMA.
> > > 
> > > https://wiki.linaro.org/LEG/Engineering/Kernel/NUMA
> > > 
> > 
> > I did find that link too, last modified 4 years ago.
> > Despite that, I could not find any ARM references in libnuma sources, but
> > Jerin proved that there is support for it.
> > 
> > http://oss.sgi.com/projects/libnuma/
> > https://github.com/numactl/numactl
> 
> Those Linaro links are very old. ARM64 NUMA supported has been added in 4.7 kernel.
> I guess we are talking about build time time dependency with libnuma here.
> Correct? I think, Even with old arm64 kernel(< 4.6), You can build against
> libnuma if it is present in rootfs. Just that at runtime, it will return
> NUMA support not available. Correct?
> 
> How hard is detect the presence of "numaif.h" if existing build system does not
> support it? If it trivial, we can enable RTE_LIBRTE_EAL_NUMA_AWARE_HUGEPAGES
> if build environment has "numaif.h".
> 
> Some example in linux kernel build system:
> http://lxr.linux.no/linux+v4.10.1/scripts/gcc-goto.sh

I think we should not try to detect numaif.h, because it should be
an error on platform supporting NUMA.
If someone really wants to build DPDK without NUMA for x86, he should
disable it in the build config file.