Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: tweak the sched_runtime_limit tunable
  sched: skip updating rq's next_balance under null SD
  sched: fix broken SMT/MC optimizations
  sched: accounting regression since rc1
  sched: fix sysctl directory permissions
  sched: sched_clock_idle_[sleep|wakeup]_event()

2 files changed, 53 insertions, 18 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 45e17b83b7f1..96e9b82246d2 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -262,7 +262,8 @@ struct rq {
         s64 clock_max_delta;
 
         unsigned int clock_warps, clock_overflows;
-        unsigned int clock_unstable_events;
+        u64 idle_clock;
+        unsigned int clock_deep_idle_events;
         u64 tick_timestamp;
 
         atomic_t nr_iowait;
@@ -556,18 +557,40 @@ static inline struct rq *this_rq_lock(void)
 }
 
 /*
- * CPU frequency is/was unstable - start new by setting prev_clock_raw:
+ * We are going deep-idle (irqs are disabled):
  */
-void sched_clock_unstable_event(void)
+void sched_clock_idle_sleep_event(void)
 {
-        unsigned long flags;
-        struct rq *rq;
+        struct rq *rq = cpu_rq(smp_processor_id());
 
-        rq = task_rq_lock(current, &flags);
-        rq->prev_clock_raw = sched_clock();
-        rq->clock_unstable_events++;
-        task_rq_unlock(rq, &flags);
+        spin_lock(&rq->lock);
+        __update_rq_clock(rq);
+        spin_unlock(&rq->lock);
+        rq->clock_deep_idle_events++;
 }
+EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
+
+/*
+ * We just idled delta nanoseconds (called with irqs disabled):
+ */
+void sched_clock_idle_wakeup_event(u64 delta_ns)
+{
+        struct rq *rq = cpu_rq(smp_processor_id());
+        u64 now = sched_clock();
+
+        rq->idle_clock += delta_ns;
+        /*
+         * Override the previous timestamp and ignore all
+         * sched_clock() deltas that occured while we idled,
+         * and use the PM-provided delta_ns to advance the
+         * rq clock:
+         */
+        spin_lock(&rq->lock);
+        rq->prev_clock_raw = now;
+        rq->clock += delta_ns;
+        spin_unlock(&rq->lock);
+}
+EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
 
 /*
  * resched_task - mark a task 'to be rescheduled now'.
@@ -2494,7 +2517,7 @@ group_next:
          * a think about bumping its value to force at least one task to be
          * moved
          */
-        if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task/2) {
+        if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task) {
                 unsigned long tmp, pwr_now, pwr_move;
                 unsigned int imbn;
 
@@ -3020,6 +3043,7 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
         struct sched_domain *sd;
         /* Earliest time when we have to do rebalance again */
         unsigned long next_balance = jiffies + 60*HZ;
+        int update_next_balance = 0;
 
         for_each_domain(cpu, sd) {
                 if (!(sd->flags & SD_LOAD_BALANCE))
@@ -3056,8 +3080,10 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
                 if (sd->flags & SD_SERIALIZE)
                         spin_unlock(&balancing);
 out:
-                if (time_after(next_balance, sd->last_balance + interval))
+                if (time_after(next_balance, sd->last_balance + interval)) {
                         next_balance = sd->last_balance + interval;
+                        update_next_balance = 1;
+                }
 
                 /*
                  * Stop the load balance at this level. There is another
@@ -3067,7 +3093,14 @@ out:
                 if (!balance)
                         break;
         }
-        rq->next_balance = next_balance;
+
+        /*
+         * next_balance will be updated only when there is a need.
+         * When the cpu is attached to null domain for ex, it will not be
+         * updated.
+         */
+        if (likely(update_next_balance))
+                rq->next_balance = next_balance;
 }
 
 /*
@@ -4890,7 +4923,7 @@ static inline void sched_init_granularity(void)
         if (sysctl_sched_granularity > gran_limit)
                 sysctl_sched_granularity = gran_limit;
 
-        sysctl_sched_runtime_limit = sysctl_sched_granularity * 4;
+        sysctl_sched_runtime_limit = sysctl_sched_granularity * 8;
         sysctl_sched_wakeup_granularity = sysctl_sched_granularity / 2;
 }
 
@@ -5234,15 +5267,16 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
 static struct ctl_table sd_ctl_dir[] = {
         {
                 .procname       = "sched_domain",
-                .mode           = 0755,
+                .mode           = 0555,
         },
         {0,},
 };
 
 static struct ctl_table sd_ctl_root[] = {
         {
+                .ctl_name       = CTL_KERN,
                 .procname       = "kernel",
-                .mode           = 0755,
+                .mode           = 0555,
                 .child          = sd_ctl_dir,
         },
         {0,},
@@ -5318,7 +5352,7 @@ static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
         for_each_domain(cpu, sd) {
                 snprintf(buf, 32, "domain%d", i);
                 entry->procname = kstrdup(buf, GFP_KERNEL);
-                entry->mode = 0755;
+                entry->mode = 0555;
                 entry->child = sd_alloc_ctl_domain_table(sd);
                 entry++;
                 i++;
@@ -5338,7 +5372,7 @@ static void init_sched_domain_sysctl(void)
         for (i = 0; i < cpu_num; i++, entry++) {
                 snprintf(buf, 32, "cpu%d", i);
                 entry->procname = kstrdup(buf, GFP_KERNEL);
-                entry->mode = 0755;
+                entry->mode = 0555;
                 entry->child = sd_alloc_ctl_cpu_table(i);
         }
         sd_sysctl_header = register_sysctl_table(sd_ctl_root);
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 87e524762b85..ab18f45f2ab2 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -154,10 +154,11 @@ static void print_cpu(struct seq_file *m, int cpu)
         P(next_balance);
         P(curr->pid);
         P(clock);
+        P(idle_clock);
         P(prev_clock_raw);
         P(clock_warps);
         P(clock_overflows);
-        P(clock_unstable_events);
+        P(clock_deep_idle_events);
         P(clock_max_delta);
         P(cpu_load[0]);
         P(cpu_load[1]);