[SRU][Vivid][V2]Pull Request: Fixes for lp:1294283

[Joseph Salisbury]

The generation 2 VMs have been assinged a memory range of 512 MiB-4096MiB with 
a starting memory of 512 MiB. They should get additional memory when needed. 
However, the total available memory in the VM stays at the intial 512 MiB and the 
kernel starts swapping instead of allocating more memory from the host.

The primary patch is commit to fix this bug is:
4e4bd36f9 - Drivers: hv: balloon: check if ha_region_mutex was acquired in MEM_CANCEL_ONLINE case

However, Vivid requires addition prereqs requested in thie pull request.

This primary patch was already applied to Wily.  However, Vivid and Trusty need backports.  
This pull request is specific to Vivid and a Trusty pull request will be sent
as it's own SRU.  This is a V2 pull request because V1 was missing this 
request details.
 


The following changes since commit 2497037c0eaad700846db8e1e716ea5f6fc06439:

  UBUNTU: Ubuntu-3.19.0-33.38 (2015-11-05 18:58:47 +0000)

are available in the git repository at:

  kernel.ubuntu.com:/srv/kernel.ubuntu.com/git/jsalisbury/bugs/lp1294283/ubuntu-vivid.git 

for you to fetch changes up to 56d40e0dd99903196eb09ad75c198f54612f1722:

  mm: initialize hotplugged pages as reserved (2015-11-20 15:59:00 -0500)

----------------------------------------------------------------
Mel Gorman (4):
      mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nid
      mm: meminit: inline some helper functions
      mm, meminit: allow early_pfn_to_nid to be used during runtime
      mm: initialize hotplugged pages as reserved

Vitaly Kuznetsov (5):
      Drivers: hv: hv_balloon: refuse to balloon below the floor
      Drivers: hv: hv_balloon: survive ballooning request with num_pages=0
      Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case
      Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX case
      Drivers: hv: balloon: check if ha_region_mutex was acquired in MEM_CANCEL_ONLINE case

 arch/ia64/mm/numa.c     | 19 ++++------
 drivers/hv/hv_balloon.c | 41 ++++++++++++---------
 include/linux/mm.h      |  6 ++--
 include/linux/mmzone.h  | 15 +++++---
 mm/memory_hotplug.c     | 10 +++++-
 mm/page_alloc.c         | 95 +++++++++++++++++++++++++++++++------------------
 6 files changed, 114 insertions(+), 72 deletions(-)