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

David Hildenbrand
2020-04-30T15:28:46Z

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@linux.intel.com>
>

--
Thanks,

David / dhildenb