sched: fix sched_info_switch not being called according to documentation

[linux-2.6-omap-h63xx.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 34bcc5bc120e5f2da970e180dfaf65d73b80dc7d..3ac3d7af04a186990bf3f849c51863e26fbb6cac 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -757,14 +757,14 @@ const_debug unsigned int sysctl_sched_features =
 #define SCHED_FEAT(name, enabled)      \
        #name ,
 
-__read_mostly char *sched_feat_names[] = {
+static __read_mostly char *sched_feat_names[] = {
 #include "sched_features.h"
        NULL
 };
 
 #undef SCHED_FEAT
 
-int sched_feat_open(struct inode *inode, struct file *filp)
+static int sched_feat_open(struct inode *inode, struct file *filp)
 {
        filp->private_data = inode->i_private;
        return 0;
@@ -1124,6 +1124,7 @@ void sched_clock_idle_sleep_event(void)
 {
        struct rq *rq = cpu_rq(smp_processor_id());
 
+       WARN_ON(!irqs_disabled());
        spin_lock(&rq->lock);
        __update_rq_clock(rq);
        spin_unlock(&rq->lock);
@@ -1139,6 +1140,7 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
        struct rq *rq = cpu_rq(smp_processor_id());
        u64 now = sched_clock();
 
+       WARN_ON(!irqs_disabled());
        rq->idle_clock += delta_ns;
        /*
         * Override the previous timestamp and ignore all
@@ -1189,6 +1191,7 @@ static inline void resched_rq(struct rq *rq)
 enum {
        HRTICK_SET,             /* re-programm hrtick_timer */
        HRTICK_RESET,           /* not a new slice */
+       HRTICK_BLOCK,           /* stop hrtick operations */
 };
 
 /*
@@ -1200,6 +1203,8 @@ static inline int hrtick_enabled(struct rq *rq)
 {
        if (!sched_feat(HRTICK))
                return 0;
+       if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags)))
+               return 0;
        return hrtimer_is_hres_active(&rq->hrtick_timer);
 }
 
@@ -1282,7 +1287,63 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
        return HRTIMER_NORESTART;
 }
 
-static inline void init_rq_hrtick(struct rq *rq)
+static void hotplug_hrtick_disable(int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+       unsigned long flags;
+
+       spin_lock_irqsave(&rq->lock, flags);
+       rq->hrtick_flags = 0;
+       __set_bit(HRTICK_BLOCK, &rq->hrtick_flags);
+       spin_unlock_irqrestore(&rq->lock, flags);
+
+       hrtick_clear(rq);
+}
+
+static void hotplug_hrtick_enable(int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+       unsigned long flags;
+
+       spin_lock_irqsave(&rq->lock, flags);
+       __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags);
+       spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+static int
+hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+       int cpu = (int)(long)hcpu;
+
+       switch (action) {
+       case CPU_UP_CANCELED:
+       case CPU_UP_CANCELED_FROZEN:
+       case CPU_DOWN_PREPARE:
+       case CPU_DOWN_PREPARE_FROZEN:
+       case CPU_DEAD:
+       case CPU_DEAD_FROZEN:
+               hotplug_hrtick_disable(cpu);
+               return NOTIFY_OK;
+
+       case CPU_UP_PREPARE:
+       case CPU_UP_PREPARE_FROZEN:
+       case CPU_DOWN_FAILED:
+       case CPU_DOWN_FAILED_FROZEN:
+       case CPU_ONLINE:
+       case CPU_ONLINE_FROZEN:
+               hotplug_hrtick_enable(cpu);
+               return NOTIFY_OK;
+       }
+
+       return NOTIFY_DONE;
+}
+
+static void init_hrtick(void)
+{
+       hotcpu_notifier(hotplug_hrtick, 0);
+}
+
+static void init_rq_hrtick(struct rq *rq)
 {
        rq->hrtick_flags = 0;
        hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
@@ -1319,6 +1380,10 @@ static inline void init_rq_hrtick(struct rq *rq)
 void hrtick_resched(void)
 {
 }
+
+static inline void init_hrtick(void)
+{
+}
 #endif
 
 /*
@@ -1438,8 +1503,8 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
 {
        u64 tmp;
 
-       if (unlikely(!lw->inv_weight))
-               lw->inv_weight = (WMULT_CONST-lw->weight/2) / (lw->weight+1);
+       if (!lw->inv_weight)
+               lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2)/(lw->weight+1);
 
        tmp = (u64)delta_exec * weight;
        /*
@@ -4339,8 +4404,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
        struct rq *rq = this_rq();
        cputime64_t tmp;
 
-       if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
-               return account_guest_time(p, cputime);
+       if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
+               account_guest_time(p, cputime);
+               return;
+       }
 
        p->stime = cputime_add(p->stime, cputime);
 
@@ -4595,9 +4662,9 @@ need_resched_nonpreemptible:
        prev->sched_class->put_prev_task(rq, prev);
        next = pick_next_task(rq, prev);
 
-       sched_info_switch(prev, next);
-
        if (likely(prev != next)) {
+               sched_info_switch(prev, next);
+
                rq->nr_switches++;
                rq->curr = next;
                ++*switch_count;
@@ -7939,6 +8006,7 @@ void __init sched_init_smp(void)
        put_online_cpus();
        /* XXX: Theoretical race here - CPU may be hotplugged now */
        hotcpu_notifier(update_sched_domains, 0);
+       init_hrtick();
 
        /* Move init over to a non-isolated CPU */
        if (set_cpus_allowed_ptr(current, &non_isolated_cpus) < 0)
@@ -8025,7 +8093,7 @@ static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
 
        se->my_q = cfs_rq;
        se->load.weight = tg->shares;
-       se->load.inv_weight = div64_u64(1ULL<<32, se->load.weight);
+       se->load.inv_weight = 0;
        se->parent = parent;
 }
 #endif
@@ -8692,7 +8760,7 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares)
                dequeue_entity(cfs_rq, se, 0);
 
        se->load.weight = shares;
-       se->load.inv_weight = div64_u64((1ULL<<32), shares);
+       se->load.inv_weight = 0;
 
        if (on_rq)
                enqueue_entity(cfs_rq, se, 0);