add extra free kbytes tunable

Add a userspace visible knob to tell the VM to keep an extra amount
of memory free, by increasing the gap between each zone's min and
low watermarks.

This is useful for realtime applications that call system
calls and have a bound on the number of allocations that happen
in any short time period.  In this application, extra_free_kbytes
would be left at an amount equal to or larger than than the
maximum number of allocations that happen in any burst.

It may also be useful to reduce the memory use of virtual
machines (temporarily?), in a way that does not cause memory
fragmentation like ballooning does.

[ccross]
Revived for use on old kernels where no other solution exists.
The tunable will be removed on kernels that do better at avoiding
direct reclaim.

Change-Id: I765a42be8e964bfd3e2886d1ca85a29d60c3bb3e
Signed-off-by: Rik van Riel<riel@redhat.com>
Signed-off-by: Colin Cross <ccross@android.com>
config: enable memory group

Required for optimal functionality of ZRAM

http://source.android.com/devices/low-ram.html

Change-Id: I6dd7b4313cfc02ecfd0c487f0cfcef4ad11001c1
S5PC11X: JPEG: add ioctl to export memory configuration

This allows userspace libs3cjpeg to read memory configuration
from the kernel instead of using the hardcoded value.

Change-Id: I61248d659dbccf2e6cc656adc7fdf18773c2fcbd
aries: optimize JPEG memory configuration

Only 1MB is required for encoding of VGA JPEG images (used by FFC).
Note that thumbnail encoding function is not used.

Requires userspace change (http://review.cyanogenmod.org/56795).

Change-Id: Icea2fc74dfc692d98ae041b785238d6b847c4ddd
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_kernel_samsung_aries into cm-11.0-ypg1-dev
YPG1: optimize JPEG memory configuration

Only 1MB is required for encoding of VGA JPEG images (used by FFC).
Note that thumbnail encoding function is not used.

Requires userspace change (http://review.cyanogenmod.org/56795).

Change-Id: Icea2fc74dfc692d98ae041b785238d6b847c4ddd