Messages in this thread | | | From | David Hildenbrand <> | Subject | Re: [PATCH v1] memory-hotplug.rst: complete admin-guide overhaul | Date | Tue, 8 Jun 2021 17:22:10 +0200 |
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Looks like a was too fast with my resend ;)
>>>> -Phases of memory hotplug >>>> +Further, the basic memory hot(un)plug infrastructure in Linux is nowadays >>>> +also used to expose PMEM, other performance-differentiated >>> >>> ^ persistent memory (PMEM) >>> > > Just in case you've missed this one ^ ;-)
I did catch that :)
[...]
>> >> "If it fails, an error will be returned by the kernel via the systemcall >> that triggered modifying of the respective file." > > I also think that write(2) to /sys/devices/system/memory/memoryXXX/online > will fail. But the inner workings of system call, its return value and the > ERRNO are probably not very interesting to a person that did > > echo 0 > /sys/devices/system/memory/memoryXXX/online > > Maybe something like > > If it fails, the state of the memory block will remain unchanged and the > above command will fail.
Thanks, I'll use that.
> > And maybe an example of how echo reports some unrelated error message :) > >>>> +Observing the State of Memory Blocks > > ... > >>>> -Now, a boot option for making a memory block which consists of migratable pages >>>> -is supported. By specifying "kernelcore=" or "movablecore=" boot option, you can >>>> -create ZONE_MOVABLE...a zone which is just used for movable pages. >>>> -(See also Documentation/admin-guide/kernel-parameters.rst) >>>> + For online memory blocks, ``DMA``, ``DMA32``, ``Normal``, >>>> + ``Movable`` and ``none`` may be returned. ``none`` indicates >>> >>> Highmem? Or we don't support hotplug on 32 bits? >> >> We only support 64 bit: >> >> config MEMORY_HOTPLUG >> ... >> depends on 64BIT || BROKEN >> >> Worth a comment in the document "Introduction": >> >> "Linux only supports memory hot(un)plug on selected 64 bit architectures, >> such as x86_64, aarch64, ppc64, s390x and ia64." > > ^ arm64 ?
I think aarch64 is historically actually the right(tm) thing to use in general ... but nowadays it doesn't matter anymore. It's "arch/arm64" ... the inconsistency is real. (interesting read: https://stackoverflow.com/questions/31851611/differences-between-arm64-and-aarch64)
But it's the same mess as using x86 vs. x86_64 vs. x64 vs. AMD64 for the 64 bit extension of IA-32.
So I'll convert that to arm64.
-- Thanks,
David / dhildenb
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