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

[David Hildenbrand <david@redhat.com>]

On 08.05.20 15:39, David Hildenbrand wrote:
> 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 \

Sorry, this line has to be

-numa node,nodeid=0,cpus=0-3,mem=4G -numa node,nodeid=1,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