> -----Original Message-----
> From: Bruce Richardson <bruce.richard...@intel.com>
> Sent: Tuesday, June 29, 2021 1:29 PM
> To: Juraj Linkeš <juraj.lin...@pantheon.tech>
> Cc: tho...@monjalon.net; david.march...@redhat.com;
> honnappa.nagaraha...@arm.com; ruifeng.w...@arm.com;
> ferruh.yi...@intel.com; jerinjac...@gmail.com; dev@dpdk.org
> Subject: Re: [PATCH v4] build: optional NUMA and cpu counts detection
>
> On Tue, Jun 29, 2021 at 12:55:05PM +0200, Juraj Linkeš wrote:
> > Add an option to automatically discover the host's numa and cpu counts
> > and use those values for a non cross-build.
> > Give users the option to override the per-arch default values or
> > values from cross files by specifying them on the command line with
> > -Dmax_lcores and -Dmax_numa_nodes.
> >
> > Signed-off-by: Juraj Linkeš <juraj.lin...@pantheon.tech>
> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> > ---
> Two very minor suggestions inline below.
>
> Acked-by: Bruce Richardson <bruce.richard...@intel.com>
>
> >
> <snip>
> > +max_lcores = get_option('max_lcores') if max_lcores == 'auto'
>
> Rather than "auto", would "detect" be a clearer name for this option value?
>
> <snip>
> > +option('max_lcores', type: 'string', value: 'default', description:
> > + 'Set maximum number of cores/threads supported by EAL. The
> > +default is different per-arch. Set to auto to detect the number of cores
> > on the
> build machine.') option('max_numa_nodes', type: 'string', value: 'default',
> description:
> > + 'Set highest NUMA node supported by EAL. The default is
> > +different per-arch. Set to auto to detect the highest numa node on
> > +the build machine.')
>
> I'd put the explicit values of "default" and "auto"(or "detect") in quotes ""
> to
> make clear they are literal values.
>
Thanks, Bruce, I'll change it. I have one extra question now that I'm looking
at the patch:
What does subprocess.run(['sysctl', '-n', 'vm.ndomains'], check=False) return
exactly? Is the the number of NUMA nodes (looks like it) or the highest NUMA
node on the system (the highest number of all NUMA nodes)? I'm asking because
of how NUMA works on P9:
NUMA node0 CPU(s): 0-63
NUMA node8 CPU(s): 64-127
NUMA node252 CPU(s):
NUMA node253 CPU(s):
NUMA node254 CPU(s):
NUMA node255 CPU(s):
Here we need not just two NUMA nodes, but at least 9 (0-8). Linux and Windows
should return the highest NUMA, not sure about FreeBSD. Or maybe we should
return the highest NUMA on which there are actual CPUs?
