lowmemorykiller.c: convert to use for_each_thread

Signed-off-by: Paul Reioux <reioux@gmail.com>
Optimized ARM RWSEM algorithm

RWSEM implementation for ARM using atomic functions.
Heavily based on arch/sh/include/asm/rwsem.h

Signed-off-by: Ashwin Chaugule <ashwinc@codeaurora.org>