Bump Surfaceflinger's binder threads to SCHED_FIFO

    // binder threads to 4.

    ProcessState::self()->setThreadPoolMaxThreadCount(4);

    // The binder threadpool we start will inherit sched policy and priority

    // of (this) creating thread. We want the binder thread pool to have

    // SCHED_FIFO policy and priority 1 (lowest RT priority)

    // Once the pool is created we reset this thread's priority back to

    // original.

    int newPriority = 0;

    int origPolicy = sched_getscheduler(0);

    struct sched_param origSchedParam;

    int errorInPriorityModification = sched_getparam(0, &origSchedParam);

    if (errorInPriorityModification == 0) {

        int policy = SCHED_FIFO;

        newPriority = sched_get_priority_min(policy);

        struct sched_param param;

        param.sched_priority = newPriority;

        errorInPriorityModification = sched_setscheduler(0, policy, &param);

    }

    // start the thread pool

    sp<ProcessState> ps(ProcessState::self());

    ps->startThreadPool();

    // Reset current thread's policy and priority

    if (errorInPriorityModification == 0) {

        errorInPriorityModification = sched_setscheduler(0, origPolicy, &origSchedParam);

    } else {

        ALOGE("Failed to set SurfaceFlinger binder threadpool priority to SCHED_FIFO");

    }

    // instantiate surfaceflinger

    sp<SurfaceFlinger> flinger = surfaceflinger::createSurfaceFlinger();

    // Set the minimum policy of surfaceflinger node to be SCHED_FIFO.

    // So any thread with policy/priority lower than {SCHED_FIFO, 1}, will run

    // at least with SCHED_FIFO policy and priority 1.

    if (errorInPriorityModification == 0) {

        flinger->setMinSchedulerPolicy(SCHED_FIFO, newPriority);

    }

    setpriority(PRIO_PROCESS, 0, PRIORITY_URGENT_DISPLAY);

    set_sched_policy(0, SP_FOREGROUND);