Messages in this thread | | | Date | Mon, 4 Nov 2013 09:56:24 -0600 | From | Russ Anderson <> | Subject | Re: [PATCH] x86: Allow NR_CPUS=1024 |
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On Mon, Nov 04, 2013 at 09:16:16AM -0500, Josh Boyer wrote: > On Mon, Nov 04, 2013 at 03:10:51PM +0100, Ingo Molnar wrote: > > * Josh Boyer <jwboyer@redhat.com> wrote: > > > > > > Why touch MAXSMP at all? It's really just a shortcut for 'configure > > > > the kernel silly large', via a single option, nothing else. You are > > > > not forced to use it and it should not affect configurability of > > > > NR_CPUS. > > > > > > > > What we _really_ want here is to fix NR_CPUS setting: to extend its > > > > range and to enforce that NR_CPUS cannot be set larger than 512 > > > > without setting CONFIG_CPUMASK_OFFSTACK. > > > > > > OK. I was just thinking that if we've come to the conclusion that 4096 > > > CPUs isn't silly large anymore, we should make MAXSMP be something we > > > consider silly large. [...] > > > > MAXSMP is also supposed to track the real hardware max as well on x86 - > > i.e. we should only increase it to 8192 etc. if such hardware exists. > > Russ, does SGI (or anyone else that you know of) have x86 hardware with > more than 4096 CPUs?
Yes. We have a system in the lab with 254 12-core IVB sockets for a total of 3048 cores. With HT is it 6096 cpus.
> If so, I can actually make a bump to the MAXSMP count a separate patch. > > josh
-- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@sgi.com
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