sched: remove PREEMPT_RESTRICT

[powerpc.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 3f6bd11..2a107e4 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,7 +75,7 @@
  */
 unsigned long long __attribute__((weak)) sched_clock(void)
 {
-       return (unsigned long long)jiffies * (1000000000 / HZ);
+       return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
 }
 
 /*
@@ -99,8 +99,8 @@ unsigned long long __attribute__((weak)) sched_clock(void)
 /*
  * Some helpers for converting nanosecond timing to jiffy resolution
  */
-#define NS_TO_JIFFIES(TIME)    ((unsigned long)(TIME) / (1000000000 / HZ))
-#define JIFFIES_TO_NS(TIME)    ((TIME) * (1000000000 / HZ))
+#define NS_TO_JIFFIES(TIME)    ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
+#define JIFFIES_TO_NS(TIME)    ((TIME) * (NSEC_PER_SEC / HZ))
 
 #define NICE_0_LOAD            SCHED_LOAD_SCALE
 #define NICE_0_SHIFT           SCHED_LOAD_SHIFT
@@ -460,7 +460,6 @@ enum {
        SCHED_FEAT_TREE_AVG             = 4,
        SCHED_FEAT_APPROX_AVG           = 8,
        SCHED_FEAT_WAKEUP_PREEMPT       = 16,
-       SCHED_FEAT_PREEMPT_RESTRICT     = 32,
 };
 
 const_debug unsigned int sysctl_sched_features =
@@ -468,8 +467,7 @@ const_debug unsigned int sysctl_sched_features =
                SCHED_FEAT_START_DEBIT          * 1 |
                SCHED_FEAT_TREE_AVG             * 0 |
                SCHED_FEAT_APPROX_AVG           * 0 |
-               SCHED_FEAT_WAKEUP_PREEMPT       * 1 |
-               SCHED_FEAT_PREEMPT_RESTRICT     * 1;
+               SCHED_FEAT_WAKEUP_PREEMPT       * 1;
 
 #define sched_feat(x) (sysctl_sched_features & SCHED_FEAT_##x)
 
@@ -4992,6 +4990,32 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
  */
 cpumask_t nohz_cpu_mask = CPU_MASK_NONE;
 
+/*
+ * Increase the granularity value when there are more CPUs,
+ * because with more CPUs the 'effective latency' as visible
+ * to users decreases. But the relationship is not linear,
+ * so pick a second-best guess by going with the log2 of the
+ * number of CPUs.
+ *
+ * This idea comes from the SD scheduler of Con Kolivas:
+ */
+static inline void sched_init_granularity(void)
+{
+       unsigned int factor = 1 + ilog2(num_online_cpus());
+       const unsigned long limit = 200000000;
+
+       sysctl_sched_min_granularity *= factor;
+       if (sysctl_sched_min_granularity > limit)
+               sysctl_sched_min_granularity = limit;
+
+       sysctl_sched_latency *= factor;
+       if (sysctl_sched_latency > limit)
+               sysctl_sched_latency = limit;
+
+       sysctl_sched_wakeup_granularity *= factor;
+       sysctl_sched_batch_wakeup_granularity *= factor;
+}
+
 #ifdef CONFIG_SMP
 /*
  * This is how migration works:
@@ -6688,10 +6712,12 @@ void __init sched_init_smp(void)
        /* Move init over to a non-isolated CPU */
        if (set_cpus_allowed(current, non_isolated_cpus) < 0)
                BUG();
+       sched_init_granularity();
 }
 #else
 void __init sched_init_smp(void)
 {
+       sched_init_granularity();
 }
 #endif /* CONFIG_SMP */
 
@@ -7228,7 +7254,7 @@ static u64 cpu_usage_read(struct cgroup *cgrp, struct cftype *cft)
                spin_unlock_irqrestore(&cpu_rq(i)->lock, flags);
        }
        /* Convert from ns to ms */
-       do_div(res, 1000000);
+       do_div(res, NSEC_PER_MSEC);
 
        return res;
 }