Re: [PATCH v2 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline

David Hildenbrand
2020-05-08T13:39:24Z

On 08.05.20 15:03, Srikar Dronamraju wrote:
> * Michal Hocko <mhocko@kernel.org> [2020-05-04 11:37:12]:
>
>>>>
>>>> Have you tested on something else than ppc? Each arch does the NUMA
>>>> setup separately and this is a big mess. E.g. x86 marks even memory less
>>>> nodes (see init_memory_less_node) as online.
>>>>
>>>
>>> while I have predominantly tested on ppc, I did test on X86 with CONFIG_NUMA
>>> enabled/disabled on both single node and multi node machines.
>>> However, I dont have a cpuless/memoryless x86 system.
>>
>> This should be able to emulate inside kvm, I believe.
>>
>
> I did try but somehow not able to get cpuless / memoryless node in a x86 kvm
> guest.

I use the following

#! /bin/bash
sudo x86_64-softmmu/qemu-system-x86_64 \
--enable-kvm \
-m 4G,maxmem=20G,slots=2 \
-smp sockets=2,cores=2 \
-numa node,nodeid=0,cpus=0-1,mem=4G -numa node,nodeid=1,cpus=2-3,mem=0G \
-kernel /home/dhildenb/git/linux/arch/x86_64/boot/bzImage \
-append "console=ttyS0 rd.shell rd.luks=0 rd.lvm=0 rd.md=0 rd.dm=0" \
-initrd /boot/initramfs-5.2.8-200.fc30.x86_64.img \
-machine pc,nvdimm \
-nographic \
-nodefaults \
-chardev stdio,id=serial \
-device isa-serial,chardev=serial \
-chardev socket,id=monitor,path=/var/tmp/monitor,server,nowait \
-mon chardev=monitor,mode=readline

to get a cpu-less and memory-less node 1. Never tried with node 0.

--
Thanks,

David / dhildenb