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.
CHROMIUM: zram: fix 32-bit overflow

The 64-bit division operator is not available in 32-bit kernels,
so have to use do_div.

BUG=chromium:245703
TEST=compiled

Change-Id: I44ab763ea9e115cef6212f6524518cf7d9eac8c7
Signed-off-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/64695
Reviewed-by: Doug Anderson <dianders@chromium.org>
PORT: Disable using battd in roms and calculate percentage by kernel battery driver

This is a port of Quarx's cpcap_battery mod
crivers: cpcap_battery: fix definition of funtions left over from module used with symsearch
build script: add option to include modified ramdisk
the modified ramdisk includes the odefault battery 10% calculation
omap4-common: Update Workaround for OMAP errata i640

The code was missing a critical barrier instruction present in
the upstream omapzoom-kernel. Synced the code to the upstream-
kernel to fix a rare issue with the LTE-modem not resuming.

Change-Id: Ia6728b7fb6807b6fc8acaa36a3baa635e9e70874
drivers:cpcap_battery: Use seperate functions for added code
Revert "drivers:cpcap_battery: Use seperate functions for added code"

This reverts commit f2131fd9092d685e1ebe06e6691a7630204388b3.
Revert "crivers: cpcap_battery: fix definition of funtions left over from module used with symsearch"

This reverts commit 1f3a5260174227acb24ba495dfe73ffaff080b2d.
Revert PORT for cpcap_battery: Needs rework as we're using a newer veryion of cpcap_battery driver
build script update
build script: Fix obsolete area
Added todays changelog and updated full history