for-next/pgtable branch: OOM error with 16K page size

quoted

From: linux-arm-kernel <redacted> on behalf of Jaggi, Manish <redacted>
Sent: Monday, February 29, 2016 5:56 PM
To: linux-arm-kernel at lists.infradead.org
Subject: for-next/pgtable branch: OOM error with 16K page size

Hi All,

I am trying to use the for-next/pgtable branch with the top commit,

The same issue is observed with for-next/core branch

quoted

commit 068a17a5805dfbca4bbf03e664ca6b19709cc7a8
Author: Mark Rutland [off-list ref]
Date:   Mon Jan 25 11:45:12 2016 +0000

  arm64: mm: create new fine-grained mappings at boot

Setup: ARMv8, Cavium ThunderX, 48Cores 64G ram.
linux config: defconfig + 16k page size.

Observations:
a) During linux boot I see some oom messages
http://pastebin.com/8jSMFhqf

b) cat /proc/meminfo

MemTotal:         66613760 kB
MemFree:          307328 kB
MemAvailable:      22416 kB

Available memory is very less compared to total.

c) With 64K pagesize
MemTotal:       66831552 kB
MemFree:         3541184 kB
MemAvailable:    3298752 kB

So it seems there is some issue with 16k only.
Need some inputs how to fix this

Regards,
Manish Jaggi