[PATCH 1/1 v4] arm: fault.c: Port OOM changes into do_page_fault

[kautuk.c @samsung.com]

Hi,

>
> These changes reduce the mmap_sem hold time, which is crucial
> during OOM killer invocation.
>
> Port these changes to ARM.

Did anyone get a chance to look at version 4 of this patch ?

I have incorporated changes as suggested by Russell during version 3 review.

Can I improve this patch in any way ?

>
> Without these changes, my ARM board encounters many hang and livelock
> scenarios.
> After applying this patch, OOM feature performance improves according to
> my testing.
>