lowmemorykiller作为内核一个module，输入参数有如下：
/sys/module/lowmemorykiller/parameters/adj 0,100,200,300,900,906
/sys/module/lowmemorykiller/parameters/cost 32
/sys/module/lowmemorykiller/parameters/debug_level 1
/sys/module/lowmemorykiller/parameters/minfree 18432,23040,27648,32256,55296,80640
adj文件包含oom_adj的阈值，minfree存放着对应的阈值，以page为单位。当对应的minfree值达到，则进程的oom_adj如果大于这个值将被杀掉。
ProcessList.java中定义的mOomAdj的值通过writeLmkd写入sysfs节点，和上面对应：
private final int[] mOomAdj = new int[] {
FOREGROUND_APP_ADJ, VISIBLE_APP_ADJ, PERCEPTIBLE_APP_ADJ,
BACKUP_APP_ADJ, CACHED_APP_MIN_ADJ, CACHED_APP_MAX_ADJ
};
// These are the low-end OOM level limits. This is appropriate for an
// HVGA or smaller phone with less than 512MB. Values are in KB.
private final int[] mOomMinFreeLow = new int[] {
12288, 18432, 24576,
36864, 43008, 49152
};
//
