On Thu, Sep 09, 2021 at 07:20:27AM +0000, Juraj Linkeš wrote: > > > > -----Original Message----- > > From: Bruce Richardson <bruce.richard...@intel.com> > > Sent: Tuesday, August 31, 2021 10:03 AM > > To: Juraj Linkeš <juraj.lin...@pantheon.tech> > > Cc: Piotr Kubaj <pku...@anongoth.pl>; David Christensen > > <d...@linux.vnet.ibm.com>; tho...@monjalon.net; > > david.march...@redhat.com; honnappa.nagaraha...@arm.com; > > ruifeng.w...@arm.com; ferruh.yi...@intel.com; jerinjac...@gmail.com; > > jer...@marvell.com; step...@networkplumber.org; dev@dpdk.org > > Subject: Re: [PATCH v5] build: optional NUMA and cpu counts detection > > > > On Tue, Aug 31, 2021 at 07:54:16AM +0000, Juraj Linkeš wrote: > > > > > > > > > > -----Original Message----- > > > > From: Piotr Kubaj <pku...@anongoth.pl> > > > > Sent: Tuesday, August 31, 2021 2:55 AM > > > > To: Juraj Linkeš <juraj.lin...@pantheon.tech> > > > > Cc: David Christensen <d...@linux.vnet.ibm.com>; tho...@monjalon.net; > > > > david.march...@redhat.com; bruce.richard...@intel.com; > > > > honnappa.nagaraha...@arm.com; ruifeng.w...@arm.com; > > > > ferruh.yi...@intel.com; jerinjac...@gmail.com; jer...@marvell.com; > > > > step...@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. > > > > > Until we are sure that we need it, can we just keep things simple? Perhaps > > we > > can use lscpu if present, and fallback to sysctl output if not. > > Piotr says lscpu isn't available on ppc FreeBSD. I think this leaves us with > two options: > 1. either use sysctl with the risk that it may not return an accurate value > 2. not support PPC for numa detection > > What do you think?
I think point #2 is more not supporting FreeBSD on PPC for numa detection rather than not supporting PPC generally, right? Personally, I am just in favour of #1 for the sake of moving forward and giving us best support with simplest code. If or when someone does hit this (FreeBSD+PPC) as a problem, then we can work with them to find best solution for fixing it. Right now we don't have anyone with the PPC+FreeBSD setup, so I'd rather ignore it than implement more complicated solutions that we can't test "just in case". /Bruce
