Re: [RFC PATCH v5 12/19] memory-hotplug: introduce new function arch_remove_memory()

[Wen Congyang]

At 07/31/2012 08:40 PM, Gerald Schaefer Wrote:
> On Mon, 30 Jul 2012 18:35:37 +0800
> Wen Congyang <wency@xxxxxxxxxxxxxx> wrote:
> 
>> At 07/30/2012 06:23 PM, Heiko Carstens Wrote:
>>> On Fri, Jul 27, 2012 at 06:32:15PM +0800, Wen Congyang wrote:
>>>> We don't call __add_pages() directly in the function add_memory()
>>>> because some other architecture related things need to be done
>>>> before or after calling __add_pages(). So we should introduce
>>>> a new function arch_remove_memory() to revert the things
>>>> done in arch_add_memory().
>>>>
>>>> Note: the function for s390 is not implemented(I don't know how to
>>>> implement it for s390).
>>>
>>> There is no hardware or firmware interface which could trigger a
>>> hot memory remove on s390. So there is nothing that needs to be
>>> implemented.
>>
>> Thanks for providing this information.
>>
>> According to this, arch_remove_memory() for s390 can just return
>> -EBUSY.
> 
> Yes, but there is a prototype mismatch for arch_remove_memory() on s390
> and also other architectures (u64 vs. unsigned long).
> 
> arch/s390/mm/init.c:262: error: conflicting types for
> âarch_remove_memoryâ include/linux/memory_hotplug.h:88: error: previous
> declaration of âarch_remove_memoryâ was here
> 
> In memory_hotplug.h you have:
> extern int arch_remove_memory(unsigned long start, unsigned long size);
> 
> On all archs other than x86 you have:
> int arch_remove_memory(u64 start, u64 size)

Thanks for pointing it out. I will fix it.

Wen Congyang

> 
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