binder: use freezable blocking calls

Avoid waking up every thread sleeping in a binder call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Change-Id: Ic4458ae90447f6caa895cc62f08e515caa7790ba
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ashmem: avoid deadlock between read and mmap calls

Avoid holding ashmem_mutex across code that can page fault.  Page faults
grab the mmap_sem for the process, which are also held by mmap calls
prior to calling ashmem_mmap, which locks ashmem_mutex.  The reversed
order of locking between the two can deadlock.

The calls that can page fault are read() and the ASHMEM_SET_NAME and
ASHMEM_GET_NAME ioctls.  Move the code that accesses userspace pages
outside the ashmem_mutex.

Bug: 9261835
Change-Id: If1322e981d29c889a56cdc9dfcbc6df2729a45e9
Signed-off-by: Todd Poynor <toddpoynor@google.com>
drivers/stagin: reduced android event_log buffer size
staging: android: lowmemorykiller: Reduce debug_level to 1

Under certain circumstances, such as after the lowmemorykiller
has recently killed an application, the logs can get flooded
with "select to kill" messages.

Change-Id: I7ae1de47c77d929e04b99be3432577d4f5fd1b2d
Signed-off-by: Liam Mark <lmark@codeaurora.org>
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
CRs-Fixed: 389463
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Git-commit: 77a6bf41d0d230ce0b2bfca58ddbea6e954fe950
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
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>
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
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>
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.
freezer: convert freezable helpers to freezer_do_not_count()

Freezing tasks will wake up almost every userspace task from
where it is blocking and force it to run until it hits a
call to try_to_sleep(), generally on the exit path from the syscall
it is blocking in.  On resume each task will run again, usually
restarting the syscall and running until it hits the same
blocking call as it was originally blocked in.

Convert the existing wait_event_freezable* wrappers to use
freezer_do_not_count().  Combined with a previous patch,
these tasks will not run during suspend or resume unless they wake
up for another reason, in which case they will run until they hit
the try_to_freeze() in freezer_count(), and then continue processing
the wakeup after tasks are thawed.

This results in a small change in behavior, previously a race
between freezing and a normal wakeup would be won by the wakeup,
now the task will freeze and then handle the wakeup after thawing.

Change-Id: I532e62251f58c1a9ca488b3fb6220c53acf7d33d
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
freezer: added missing definition of wait_event_freezable_exclusive
freezer: added missing definition of NR_FREE_CMA_PAGES