Re: [PATCH v2 3/3] device-dax: Add system ram (add_memory()) with MHP_NO_FIRMWARE_MEMMAP

[David Hildenbrand <david@xxxxxxxxxx>]

On 30.04.20 13:23, Dave Hansen wrote:
> On 4/30/20 3:29 AM, David Hildenbrand wrote:
>> Currently, when adding memory, we create entries in /sys/firmware/memmap/
>> as "System RAM". This does not reflect the reality and will lead to
>> kexec-tools to add that memory to the fixed-up initial memmap for a
>> kexec kernel (loaded via kexec_load()). The memory will be considered
>> initial System RAM by the kexec kernel.
>>
>> We should let the kexec kernel decide how to use that memory - just as
>> we do during an ordinary reboot.
> ...
>> -    rc = add_memory(numa_node, new_res->start, resource_size(new_res), 0);
>> +    rc = add_memory(numa_node, new_res->start, resource_size(new_res),
>> +                    MHP_NO_FIRMWARE_MEMMAP);
> 
> Looks fine.  But, if you send another revision, could you add a comment
> about the actual goal of MHP_NO_FIRMWARE_MEMMAP?  Maybe:
> 
>       /*
>        * MHP_NO_FIRMWARE_MEMMAP ensures that future
>        * kexec'd kernels will not treat this as RAM.
>        */
> 
> Not a biggie, though.

Sure, maybe Andrew can fixup when applying (if no resend is necessary).

Thanks Dave!

> 
> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> 


-- 
Thanks,

David / dhildenb