怎样取子进程的内存使用情况

fork出来应该能获取到子进程Id，然后进/proc读取对应进程的相关信息

ActivityManager activityManager = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);
MemoryInfo memoryInfo = new ActivityManager.MemoryInfo();
activityManager.getMemoryInfo(memoryInfo);

Log.i(TAG, " memoryInfo.availMem " + memoryInfo.availMem + "n" );
Log.i(TAG, " memoryInfo.lowMemory " + memoryInfo.lowMemory + "n" );
Log.i(TAG, " memoryInfo.threshold " + memoryInfo.threshold + "n" );

List runningAppProcesses = activityManager.getRunningAppProcesses();

Map pidMap = new TreeMap();
for (RunningAppProcessInfo runningAppProcessInfo : runningAppProcesses)
{

pidMap.put(runningAppProcessInfo.pid, runningAppProcessInfo.processName);

}
Collection keys = pidMap.keySet();

for(int key : keys)
{

int pids[] = new int[1];
pids[0] = key;
android.os.Debug.MemoryInfo[] memoryInfoArray = activityManager.getProcessMemoryInfo(pids);
for(android.os.Debug.MemoryInfo pidMemoryInfo: memoryInfoArray)
{
    Log.i(TAG, String.format("** MEMINFO in pid %d [%s] **\n",pids[0],pidMap.get(pids[0])));
    Log.i(TAG, " pidMemoryInfo.getTotalPrivateDirty(): " + pidMemoryInfo.getTotalPrivateDirty() + "\n");
    Log.i(TAG, " pidMemoryInfo.getTotalPss(): " + pidMemoryInfo.getTotalPss() + "\n");
    Log.i(TAG, " pidMemoryInfo.getTotalSharedDirty(): " + pidMemoryInfo.getTotalSharedDirty() + "\n");
}

}