Re: [Patch V2 2/2] x86/mm/numa: remove the numa_nodemask_from_meminfo()

From: Borislav Petkov
Date: Mon Apr 10 2017 - 08:43:47 EST


On Sun, Apr 09, 2017 at 11:12:14AM +0800, Wei Yang wrote:
> Oops, sorry to bring in the regression with my cleanup.
> I haven't noticed there is a kernel command line "numa=fake", which
> is the cause of the crash I think.

Of course it is, didn't you see my debugging upthread?

> So from my understanding, I am goting to do these tests:
>
> 1. all fake numa scenarios with Kirill's qemu command line

It is enough if you boot the kernel with "numa=fake..."

> 2. Real numa scenarios with following qemu command option

Not qemu command option but a kernel cmdline option.

> 3. Baremetal
>
> One more question, on the baremetal mathine, I can't change the
> numa configuration, so there would be only one case. Do you have
> some specific requirement?

numa=fake on baremetal too.

> Well, if I missed something, just let me know :-)
>
> > Qemu can emulate real numa too, for example you can boot with:
> >
> > -smp 64 \
> > -numa node,nodeid=0,cpus=1-8 \
> > -numa node,nodeid=1,cpus=9-16 \
> > -numa node,nodeid=2,cpus=17-24 \
> > -numa node,nodeid=3,cpus=25-32 \
> > -numa node,nodeid=4,cpus=0 \
> > -numa node,nodeid=4,cpus=33-39 \
> > -numa node,nodeid=5,cpus=40-47 \
> > -numa node,nodeid=6,cpus=48-55 \
> > -numa node,nodeid=7,cpus=56-63

Also, do this in kvm. kvm can emulate a lot of numa configurations, do
experiment with those too.

Basically, try to break your "cleanup". Stuff one should do for every
patch one sends anyway.

--
Regards/Gruss,
Boris.

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