[PATCH 0/3] ARM 4Kstacks: introduction

[Andi Kleen]

>> If system run for some time, sometimes it may be difficult for
>> memory allocator to allocate 2 continuous page frames even  there are
>> many spare page frames in system because of
>> fragment issue, so the patch does make sense. Anyway,
>> it provides one option for user to apply 4k stack to avoid
>> such kind of process creation failure.
>
> Can't page migration be used in these situations?

The kernel already uses it of course, assuming the pages are movable.
So if you are really worried about this, just define a movable zone.

-Andi