mm: compaction: compact normal zone

Compact normal zone when system run into early suspend.

There isn't need to compact other zones since there isn't
big memory block needs in those zones on our platform.

This is ported from the following patch:

 * (CR) compact normal zone only in early suspend
   Reviewed-on: http://gerrit.pcs.mot.com/494963

Change-Id: If81d1d440a365bd54a6bd6d23ef851493280692c
Signed-off-by: Yi-wei Zhao <gbjc64@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/507168
Tested-by: Jira Key <JIRAKEY@motorola.com>
Reviewed-by: Jason Hrycay <jason.hrycay@motorola.com>
(cherry picked from commit a8cb0d740ddbe26511f280b958d6c6b41e7bb7e2)
mm: compaction: disable compaction deferring

Originally if compaction fails in slowpath, it will defer the
following compaction request (by 64 times at most), and try
direct reclaim.  But if the memory has been fragmented, and
reclaim can't resolve the problem, OOM will be triggered soon.
Disabling the deferring will let compaction run as much as it can.

Because majority of page request is with order = 0 in our
current platform; memory compaction in the slowpath occurs
rarely. The performacne impact is very low.

This is ported from the following patch:

 * (CR) mem compaction enhancement
   Reviewed-on: http://gerrit.pcs.mot.com/494962

Change-Id: Iaf107d20d6905ac998dc861d3c7bfa0185937958
Signed-off-by: Yi-wei Zhao <gbjc64@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/507229
Tested-by: Jira Key <JIRAKEY@motorola.com>
Reviewed-by: Jason Hrycay <jason.hrycay@motorola.com>
(cherry picked from commit 73c03e5b4bc40e927a21300a70cfb75335b6dce9)
compact all zones on earlysuspend

mm: compaction: add Android-specific hook.

On larger memory configurations the bulk of memory is in the high
zone and in the 3.4 Android kernels ION and KGSL attempt to make
large allocations. So it's no longer enough to compact just normal
zone. That simplifies things by removing the need for some code.
The suitability of compaction per zone is checked implicitly, so we
will only do anything "expensive" when there's a good reason. Given
that the screen is off at that time, user won't notice anything.
This takes about 150ms on 2GB configuration with MSM8960pro CPU.

Also the code added previously to install earlysuspend handler
was not properly checking for CONFIG_HAS_EARLYSUSPEND, which means
Android-specific code has been stuffed into generic kernel code.
Fix that too, while we're at it.

Change-Id: Icd7b5ec3a304d47611602bdac3e2aad6f4faf8c1
Signed-off-by: Igor Kovalenko <cik009@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/522737
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
(cherry picked from commit 88cdf7ab16589afff4f72226980541e15816c8f4)
mm: compaction: do suspend compaction in workqueue

Move compact_nodes_suspend out of the direct early suspend workqueue
to avoid long delays in the suspend path on a heavily loaded system;
examples being heavily use of filesystem contending with the pages
that are trying to be compacted.

Signed-off-by: Yuan Jiangli <jlyuan@motorola.com>
Reviewed-on: http://gerrit.pcs.mot.com/535748
SLT-Approved: Slta Waiver <sltawvr@motorola.com>
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Christopher Fries <qcf001@motorola.com>
Reviewed-by: Igor Kovalenko <cik009@motorola.com>
Reviewed-by: Klocwork kwcheck <klocwork-kwcheck@sourceforge.mot.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
Reviewed-by: Check Patch <CHEKPACH@motorola.com>

(cherry-pick from commit  6e202c2572708430f682987b2240eae50dadb1e3)

Change-Id: Ifcf8e0ff8f60d3c7f099d95653a43ba9651eeb28
Reviewed-on: http://gerrit.pcs.mot.com/540977
SLT-Approved: Slta Waiver <sltawvr@motorola.com>
Tested-by: Jira Key <jirakey@motorola.com>
Reviewed-by: Yi-Wei Zhao <gbjc64@motorola.com>
Submit-Approved: Jira Key <jirakey@motorola.com>
Revert mm/shmem.c. & mm/truncate.c changes applied in Kernel update 3.4.100

Revert "shmem: fix splicing from a hole while it's punched"
commit b1a366500bd537b50c3aad26dc7df083ec03a448 upstream.

Revert "shmem: fix faulting into a hole, not taking i_mutex"
commit 8e205f779d1443a94b5ae81aa359cb535dd3021e upstream.

Revert "shmem: fix faulting into a hole while it's punched"
commit f00cdc6df7d7cfcabb5b740911e6788cb0802bdb upstream.

May cause memory failures.