Andi Kleen <mailto:[email protected]> wrote:
>> In general SRAT has a hotplug memory bit so it's possible
>> to predict how much memory there will be in advance. Since
>> the overhead of the kernel page tables should be very
>> low I would prefer if you just used instead.
>>
>> (i.e. instead of extending the kernel mapping preallocate
>> the direct mapping and just clear the P bits)
>>
>> That should be much simpler.
>
> Looking at it again - accessing SRAT currently relies on the
> direct mapping already. Untangling that would be possible,
> but require an bt_ioremap which would also add lots of code.
>
> Ok I retract that objection. I guess your way is better
> for now.
Thanks for considering this Andi.
> In addition to the __cpuinit comment
>
> +if (after_bootmem) spin_unlock(&init_mm.page_table_lock);
>
> Conditional locking is evil. spinlocking in the boot
> case should just work too I think.
>
> The EXPORTs should be probably EXPORT_SYMBOL_GPL.
>
> With these changes it would look ok for me.
Excellent points. Thanks for the review and suggestions. I'm
testing a revised patch now and will repost in a bit.
matt