Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

[firefly-linux-kernel-4.4.55.git] / kernel / sched / walt.c

diff --git a/kernel/sched/walt.c b/kernel/sched/walt.c
index b9ae8d5c4393ada4a0355ea1fdbbbdec81a6c38d..6e053bd9830c785fdf68de27f635d9380f017cdb 100644 (file)
--- a/kernel/sched/walt.c
+++ b/kernel/sched/walt.c
@@ -62,8 +62,6 @@ static unsigned int max_possible_freq = 1;
  */
 static unsigned int min_max_freq = 1;
 
-static unsigned int max_capacity = 1024;
-static unsigned int min_capacity = 1024;
 static unsigned int max_load_scale_factor = 1024;
 static unsigned int max_possible_capacity = 1024;
 
@@ -185,7 +183,12 @@ update_window_start(struct rq *rq, u64 wallclock)
        int nr_windows;
 
        delta = wallclock - rq->window_start;
-       BUG_ON(delta < 0);
+       /* If the MPM global timer is cleared, set delta as 0 to avoid kernel BUG happening */
+       if (delta < 0) {
+               delta = 0;
+               WARN_ONCE(1, "WALT wallclock appears to have gone backwards or reset\n");
+       }
+
        if (delta < walt_ravg_window)
                return;
 
@@ -864,39 +867,6 @@ void walt_fixup_busy_time(struct task_struct *p, int new_cpu)
                double_rq_unlock(src_rq, dest_rq);
 }
 
-/* Keep track of max/min capacity possible across CPUs "currently" */
-static void __update_min_max_capacity(void)
-{
-       int i;
-       int max = 0, min = INT_MAX;
-
-       for_each_online_cpu(i) {
-               if (cpu_rq(i)->capacity > max)
-                       max = cpu_rq(i)->capacity;
-               if (cpu_rq(i)->capacity < min)
-                       min = cpu_rq(i)->capacity;
-       }
-
-       max_capacity = max;
-       min_capacity = min;
-}
-
-static void update_min_max_capacity(void)
-{
-       unsigned long flags;
-       int i;
-
-       local_irq_save(flags);
-       for_each_possible_cpu(i)
-               raw_spin_lock(&cpu_rq(i)->lock);
-
-       __update_min_max_capacity();
-
-       for_each_possible_cpu(i)
-               raw_spin_unlock(&cpu_rq(i)->lock);
-       local_irq_restore(flags);
-}
-
 /*
  * Return 'capacity' of a cpu in reference to "least" efficient cpu, such that
  * least efficient cpu gets capacity of 1024
@@ -979,15 +949,9 @@ static int cpufreq_notifier_policy(struct notifier_block *nb,
        /* Initialized to policy->max in case policy->related_cpus is empty! */
        unsigned int orig_max_freq = policy->max;
 
-       if (val != CPUFREQ_NOTIFY && val != CPUFREQ_REMOVE_POLICY &&
-                                               val != CPUFREQ_CREATE_POLICY)
+       if (val != CPUFREQ_NOTIFY)
                return 0;
 
-       if (val == CPUFREQ_REMOVE_POLICY || val == CPUFREQ_CREATE_POLICY) {
-               update_min_max_capacity();
-               return 0;
-       }
-
        for_each_cpu(i, policy->related_cpus) {
                cpumask_copy(&cpu_rq(i)->freq_domain_cpumask,
                             policy->related_cpus);
@@ -1077,8 +1041,6 @@ static int cpufreq_notifier_policy(struct notifier_block *nb,
                max_load_scale_factor = highest_mplsf;
        }
 
-       __update_min_max_capacity();
-
        return 0;
 }