Re: [PATCH v3] mm: fix panic in __alloc_pages

[Alexey Makhalov]

> On Dec 9, 2021, at 1:56 AM, Michal Hocko <mhocko@xxxxxxxx> wrote:
> 
> On Thu 09-12-21 09:28:55, Alexey Makhalov wrote:
>> 
>> 
>> [    0.081777] Node 4 uninitialized by the platform. Please report with boot dmesg.
>> [    0.081790] Initmem setup node 4 [mem 0x0000000000000000-0x0000000000000000]
>> ...
>> [    0.086441] Node 127 uninitialized by the platform. Please report with boot dmesg.
>> [    0.086454] Initmem setup node 127 [mem 0x0000000000000000-0x0000000000000000]
> 
> Interesting that only those two didn't get a proper arch specific
> initialization. Could you check why? I assume init_cpu_to_node
> doesn't see any CPU pointing at this node. Wondering why that would be
> the case but that can be a bug in the affinity tables.

My bad shrinking. Not just these 2, but all possible and not present nodes from 4 to 127
are having this message.


> 
>> vCPU/node hot add works.
>> Onlining works as well, but with warning. I do not think it is related to the patch:
>> [   36.838838] CPU4 has been hot-added
>> [   36.838987] acpi_processor_hotadd_init:205 cpu 4, node 4, online 0, ndata 00000000e9c7f79b
>> [   48.480498] Built 4 zonelists, mobility grouping on.  Total pages: 961440
>> [   48.480508] Policy zone: Normal
>> [   48.508318] smpboot: Booting Node 4 Processor 4 APIC 0x8
>> [   48.509255] Disabled fast string operations
>> [   48.509807] smpboot: CPU 4 Converting physical 8 to logical package 4
>> [   48.509825] smpboot: CPU 4 Converting physical 0 to logical die 4
>> [   48.510040] WARNING: workqueue cpumask: online intersect > possible intersect
> 
> I will double check. There are changes required on the hotplug side. I
> would like to see that this one doesn't blow up before diving there.
> 
>> [   48.510324] vmware: vmware-stealtime: cpu 4, pa 3e667000
>> [   48.511311] Will online and init hotplugged CPU: 4
>> 
>> Hot remove does not quite work. It might be issue in ACPI/Firmware code or Hypervisor. Debugging…
>> 
>> Do you want me to perform any specific tests?
> 
> No, not really. AFAIU your issue has been reproducible during boot and
> that seems to be fixed. I will work on the hotplug side of the things
> and post something resembling a real patch soon. That would require also
> memory hotplug testing.
I can help you with memory hotplug testing if needed.

Thanks,
—Alexey

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