Re: [dpdk-dev] [PATCH v5] build: optional NUMA and cpu counts detection

[Piotr Kubaj <pkubaj@anongoth.pl>]

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On 21-08-31 07:54:16, Juraj Linkeš wrote:
> 
> 
> > -----Original Message-----
> > From: Piotr Kubaj <pkubaj@anongoth.pl>
> > Sent: Tuesday, August 31, 2021 2:55 AM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: David Christensen <drc@linux.vnet.ibm.com>; thomas@monjalon.net;
> > david.marchand@redhat.com; bruce.richardson@intel.com;
> > Honnappa.Nagarahalli@arm.com; Ruifeng.Wang@arm.com;
> > ferruh.yigit@intel.com; jerinjacobk@gmail.com; jerinj@marvell.com;
> > stephen@networkplumber.org; dev@dpdk.org
> > Subject: Re: [PATCH v5] build: optional NUMA and cpu counts detection
> > 
> > Hi,
> > 
> > sorry for the late answer.
> 
> Thanks for the answer anyway, better late than never.
> 
> > 
> > I suppose you mean sysctl command, not systemctl.
> > 
> 
> That's right. What does lscpu say? Are the NUMA nodes non-contiguous like this?:
> 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):
> 
> > On dual CPU systems, it returns 2. On single CPU ones, 1.
> 
> I asked the previous question so that we know the actual numa node number of the second CPU. If it's 8, then sysctl does some renumeration and we can't use it.
> 
> Bruce, maybe we should just parse lscpu output? That introduces a dependency, but that may not be such a big deal as lscpu is pretty common.
There's no lscpu on FreeBSD in the base system. There is one in packages, but it's written only for amd64 / i386 since it uses CPUID. https://github.com/NanXiao/lscpu


> 
> > 
> > On 21-08-03 10:21:50, Juraj Linkeš wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: David Christensen <drc@linux.vnet.ibm.com>
> > > > Sent: Tuesday, August 3, 2021 1:29 AM
> > > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>; thomas@monjalon.net;
> > > > david.marchand@redhat.com; bruce.richardson@intel.com;
> > > > Honnappa.Nagarahalli@arm.com; Ruifeng.Wang@arm.com;
> > > > ferruh.yigit@intel.com; jerinjacobk@gmail.com; jerinj@marvell.com;
> > > > stephen@networkplumber.org; Piotr Kubaj <pkubaj@FreeBSD.org>
> > > > Cc: dev@dpdk.org
> > > > Subject: Re: [PATCH v5] build: optional NUMA and cpu counts
> > > > detection
> > > >
> > > >
> > > >
> > > > On 8/2/21 5:44 AM, Juraj Linkeš wrote:
> > > > >> +if os.name == 'posix':
> > > > >> +    if os.path.isdir('/sys/devices/system/node'):
> > > > >> +        numa_nodes = glob.glob('/sys/devices/system/node/node*')
> > > > >> +        numa_nodes.sort()
> > > > >> +        print(int(os.path.basename(numa_nodes[-1])[4:]) + 1)
> > > > >> +    else:
> > > > >> +        subprocess.run(['sysctl', '-n', 'vm.ndomains'],
> > > > >> +check=False)
> > > > >> +
> > > > >
> > > > > Bruce, David, Thomas,
> > > > >
> > > > > Is DPDK actually supported on Power9 FreeBSD? Is anyone using this
> > > > combination? How can we address the open question of what exactly
> > > > does sysctl -n vm.ndomains return on a Power9 FreeBSD system? Or
> > > > should we just leave it as is? Or maybe add 1 to the output (as we do in other
> > cases)?
> > > >
> > > > Not supported within IBM, but you can buy OpenPOWER boxes from 3rd
> > > > parties such as Raptor Computing Systems so there may be customers
> > > > using DPDK on POWER with FreeBSD that I don't track.  Adding Piotr
> > > > Kubaj who has commented on POWER/FreeBSD issues in this past.
> > > >
> > > > Dave
> > >
> > > Thanks, David.
> > >
> > > Piotr, to provide more context, we're trying to figure out what the highest
> > NUMA node on a system is.
> > > On P9 systems, here's how NUMA nodes look like in Linux:
> > > 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):
> > > The highest NUMA with CPUs is node8.
> > >
> > > We're trying to get the highest NUMA with CPUs on P9 FreeBSD systems, but
> > we don't know whether FreeBSD NUMA layout looks the same (does FreeBSD
> > report non-contiguous NUMA nodes as Linxu above, or does it renumerate) a
> > what does "systemctl -n vm.ndomains" return. Could you check these for us?

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