Revert "android/lowmemorykiller: Check all tasks for death pending"

This reverts commit 75eb6d4db2ce97c625e887e9bbdd065607864e70.
Revert "staging: android: lowmemorykiller: Add config option to support oom_adj values"

This reverts commit a20bd296efc12cef27e99b28ecf2c47c31f28647.
android: lowmemorykiller: add lmk parameters tunning code.

There are cases that LMK doesn't run, even when it must run.
It is due to LMK shrinker not considering memory status per zone.
So add LMK parameters(other_free, other_file) tunnig code to
consider target zone of LMK shrinker.

Change-Id: I6f1f8660d5da920a0e3af45a160499965032081d
staging: android: lowmemorykiller: Add config option to support oom_adj values

The conversion to use oom_score_adj instead of the deprecated oom_adj
values breaks existing user-space code. Add a config option to convert
oom_adj values written to oom_score_adj values if they appear to be
valid oom_adj values.

Change-Id: I68308125059b802ee2991feefb07e9703bc48549
Signed-off-by: Arve Hjønnevåg <arve@android.com>
staging: android: lowmemorykiller: Don't count reserved free memory

The amount of reserved memory varies between devices. Subtract it
here to reduce the amount of devices specific tuning needed for the
minfree values.

Change-Id: I466ae8b18f5972f6f6d8b5a7d8c4ae69660de53a
Signed-off-by: Arve Hjønnevåg <arve@android.com>
staging: android: lowmemorykiller: Change default debug_level to 1

The select...to kill messages are not very useful when not debugging
the lowmemorykiller itself. After the change to check TIF_MEMDIE
instead of using a task notifer this message can also get very
noisy.

Change-Id: Ice171c25801d6faa454b885a23b24b002423b754
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Revert "staging: android: lowmemorykiller: Don't count reserved free memory"

This reverts commit 4971f84bfce8bd180287c8cb94136ac89d328f1d

Change-Id: I6c51caef9c6bdf0ec86d2c155aab0313c54272e8
android/lowmemorykiller: Check all tasks for death pending

The lowmemorykiller uses the TIF_MEMDIE flag to help ensure it doesn't
kill another task until the memory from the previously killed task has
been returned to the system.

However the lowmemorykiller does not currently look at tasks who do not
have a tasks->mm, but just because a process doesn't have a tasks->mm
does not mean that the task's memory has been fully returned to the
system yet.

In order to prevent the lowmemorykiller from unnecessarily killing
multiple applications in a row the lowmemorykiller has been changed to
ensure that previous killed tasks are no longer in the process list
before attempting to kill another task.

Change-Id: I7d8a8fd39ca5625e6448ed2efebfb621f6e93845
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
android/lowmemorykiller: Selectively count free CMA pages

In certain memory configurations there can be a large number of
CMA pages which are not suitable to satisfy certain memory
requests.

This large number of unsuitable pages can cause the
lowmemorykiller to not kill any tasks because the
lowmemorykiller counts all free pages.
In order to ensure the lowmemorykiller properly evaluates the
free memory only count the free CMA pages if they are suitable
for satisfying the memory request.

Change-Id: I7f06d53e2d8cfe7439e5561fe6e5209ce73b1c90
CRs-fixed: 437016
Signed-off-by: Liam Mark <lmark@codeaurora.org>
android/lowmemorykiller: Wait for memory to be freed

The memory reclaim code needs to give time to the system to
return the memory from a killed process otherwise the memory
reclaim code could run continuously, in multiple threads,
which could starve both the watchdog thread and the thread
which is responsible for returning the memory from the
killed process.

Change-Id: Ib390dbb021cb6d41e74ac64eca6fef46367daf1e
CRs-fixed: 447740
Signed-off-by: Liam Mark <lmark@codeaurora.org>
android/lowmemorykiller: Ignore tasks with freed mm

A killed task can stay in the task list long after its
memory has been returned to the system, therefore
ignore any tasks whose mm struct has been freed.

Change-Id: I76394b203b4ab2312437c839976f0ecb7b6dde4e
CRs-fixed: 450383
Signed-off-by: Liam Mark <lmark@codeaurora.org>