X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=kernel%2Fsched.c;h=b9a6837301482270dc7438a3df3539b9ac835f94;hb=aa45e2569ffe963dfbbbfddfdccd12afe69b2d65;hp=1fd67e16cd315388a67ba085dad46bb266bb5d93;hpb=574009c1a895aeeb85eaab29c235d75852b09eb8;p=karo-tx-linux.git

diff --git a/kernel/sched.c b/kernel/sched.c
index 1fd67e16cd31..b9a683730148 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1853,6 +1853,13 @@ context_switch(struct rq *rq, struct task_struct *prev,
 	struct mm_struct *mm = next->mm;
 	struct mm_struct *oldmm = prev->active_mm;
 
+	/*
+	 * For paravirt, this is coupled with an exit in switch_to to
+	 * combine the page table reload and the switch backend into
+	 * one hypercall.
+	 */
+	arch_enter_lazy_cpu_mode();
+
 	if (!mm) {
 		next->active_mm = oldmm;
 		atomic_inc(&oldmm->mm_count);
@@ -2897,14 +2904,16 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
 static void update_load(struct rq *this_rq)
 {
 	unsigned long this_load;
-	int i, scale;
+	unsigned int i, scale;
 
 	this_load = this_rq->raw_weighted_load;
 
 	/* Update our load: */
-	for (i = 0, scale = 1; i < 3; i++, scale <<= 1) {
+	for (i = 0, scale = 1; i < 3; i++, scale += scale) {
 		unsigned long old_load, new_load;
 
+		/* scale is effectively 1 << i now, and >> i divides by scale */
+
 		old_load = this_rq->cpu_load[i];
 		new_load = this_load;
 		/*
@@ -2914,7 +2923,7 @@ static void update_load(struct rq *this_rq)
 		 */
 		if (new_load > old_load)
 			new_load += scale-1;
-		this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) / scale;
+		this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i;
 	}
 }
 
@@ -2997,23 +3006,6 @@ static inline void idle_balance(int cpu, struct rq *rq)
 }
 #endif
 
-static inline void wake_priority_sleeper(struct rq *rq)
-{
-#ifdef CONFIG_SCHED_SMT
-	if (!rq->nr_running)
-		return;
-
-	spin_lock(&rq->lock);
-	/*
-	 * If an SMT sibling task has been put to sleep for priority
-	 * reasons reschedule the idle task to see if it can now run.
-	 */
-	if (rq->nr_running)
-		resched_task(rq->idle);
-	spin_unlock(&rq->lock);
-#endif
-}
-
 DEFINE_PER_CPU(struct kernel_stat, kstat);
 
 EXPORT_PER_CPU_SYMBOL(kstat);
@@ -3230,10 +3222,7 @@ void scheduler_tick(void)
 
 	update_cpu_clock(p, rq, now);
 
-	if (p == rq->idle)
-		/* Task on the idle queue */
-		wake_priority_sleeper(rq);
-	else
+	if (p != rq->idle)
 		task_running_tick(rq, p);
 #ifdef CONFIG_SMP
 	update_load(rq);
@@ -3242,136 +3231,6 @@ void scheduler_tick(void)
 #endif
 }
 
-#ifdef CONFIG_SCHED_SMT
-static inline void wakeup_busy_runqueue(struct rq *rq)
-{
-	/* If an SMT runqueue is sleeping due to priority reasons wake it up */
-	if (rq->curr == rq->idle && rq->nr_running)
-		resched_task(rq->idle);
-}
-
-/*
- * Called with interrupt disabled and this_rq's runqueue locked.
- */
-static void wake_sleeping_dependent(int this_cpu)
-{
-	struct sched_domain *tmp, *sd = NULL;
-	int i;
-
-	for_each_domain(this_cpu, tmp) {
-		if (tmp->flags & SD_SHARE_CPUPOWER) {
-			sd = tmp;
-			break;
-		}
-	}
-
-	if (!sd)
-		return;
-
-	for_each_cpu_mask(i, sd->span) {
-		struct rq *smt_rq = cpu_rq(i);
-
-		if (i == this_cpu)
-			continue;
-		if (unlikely(!spin_trylock(&smt_rq->lock)))
-			continue;
-
-		wakeup_busy_runqueue(smt_rq);
-		spin_unlock(&smt_rq->lock);
-	}
-}
-
-/*
- * number of 'lost' timeslices this task wont be able to fully
- * utilize, if another task runs on a sibling. This models the
- * slowdown effect of other tasks running on siblings:
- */
-static inline unsigned long
-smt_slice(struct task_struct *p, struct sched_domain *sd)
-{
-	return p->time_slice * (100 - sd->per_cpu_gain) / 100;
-}
-
-/*
- * To minimise lock contention and not have to drop this_rq's runlock we only
- * trylock the sibling runqueues and bypass those runqueues if we fail to
- * acquire their lock. As we only trylock the normal locking order does not
- * need to be obeyed.
- */
-static int
-dependent_sleeper(int this_cpu, struct rq *this_rq, struct task_struct *p)
-{
-	struct sched_domain *tmp, *sd = NULL;
-	int ret = 0, i;
-
-	/* kernel/rt threads do not participate in dependent sleeping */
-	if (!p->mm || rt_task(p))
-		return 0;
-
-	for_each_domain(this_cpu, tmp) {
-		if (tmp->flags & SD_SHARE_CPUPOWER) {
-			sd = tmp;
-			break;
-		}
-	}
-
-	if (!sd)
-		return 0;
-
-	for_each_cpu_mask(i, sd->span) {
-		struct task_struct *smt_curr;
-		struct rq *smt_rq;
-
-		if (i == this_cpu)
-			continue;
-
-		smt_rq = cpu_rq(i);
-		if (unlikely(!spin_trylock(&smt_rq->lock)))
-			continue;
-
-		smt_curr = smt_rq->curr;
-
-		if (!smt_curr->mm)
-			goto unlock;
-
-		/*
-		 * If a user task with lower static priority than the
-		 * running task on the SMT sibling is trying to schedule,
-		 * delay it till there is proportionately less timeslice
-		 * left of the sibling task to prevent a lower priority
-		 * task from using an unfair proportion of the
-		 * physical cpu's resources. -ck
-		 */
-		if (rt_task(smt_curr)) {
-			/*
-			 * With real time tasks we run non-rt tasks only
-			 * per_cpu_gain% of the time.
-			 */
-			if ((jiffies % DEF_TIMESLICE) >
-				(sd->per_cpu_gain * DEF_TIMESLICE / 100))
-					ret = 1;
-		} else {
-			if (smt_curr->static_prio < p->static_prio &&
-				!TASK_PREEMPTS_CURR(p, smt_rq) &&
-				smt_slice(smt_curr, sd) > task_timeslice(p))
-					ret = 1;
-		}
-unlock:
-		spin_unlock(&smt_rq->lock);
-	}
-	return ret;
-}
-#else
-static inline void wake_sleeping_dependent(int this_cpu)
-{
-}
-static inline int
-dependent_sleeper(int this_cpu, struct rq *this_rq, struct task_struct *p)
-{
-	return 0;
-}
-#endif
-
 #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
 
 void fastcall add_preempt_count(int val)
@@ -3498,7 +3357,6 @@ need_resched_nonpreemptible:
 		if (!rq->nr_running) {
 			next = rq->idle;
 			rq->expired_timestamp = 0;
-			wake_sleeping_dependent(cpu);
 			goto switch_tasks;
 		}
 	}
@@ -3538,8 +3396,6 @@ need_resched_nonpreemptible:
 		}
 	}
 	next->sleep_type = SLEEP_NORMAL;
-	if (dependent_sleeper(cpu, rq, next))
-		next = rq->idle;
 switch_tasks:
 	if (next == rq->idle)
 		schedstat_inc(rq, sched_goidle);
@@ -3557,7 +3413,7 @@ switch_tasks:
 
 	sched_info_switch(prev, next);
 	if (likely(prev != next)) {
-		next->timestamp = now;
+		next->timestamp = next->last_ran = now;
 		rq->nr_switches++;
 		rq->curr = next;
 		++*switch_count;
@@ -4831,32 +4687,10 @@ out_unlock:
 	return retval;
 }
 
-static inline struct task_struct *eldest_child(struct task_struct *p)
-{
-	if (list_empty(&p->children))
-		return NULL;
-	return list_entry(p->children.next,struct task_struct,sibling);
-}
-
-static inline struct task_struct *older_sibling(struct task_struct *p)
-{
-	if (p->sibling.prev==&p->parent->children)
-		return NULL;
-	return list_entry(p->sibling.prev,struct task_struct,sibling);
-}
-
-static inline struct task_struct *younger_sibling(struct task_struct *p)
-{
-	if (p->sibling.next==&p->parent->children)
-		return NULL;
-	return list_entry(p->sibling.next,struct task_struct,sibling);
-}
-
 static const char stat_nam[] = "RSDTtZX";
 
 static void show_task(struct task_struct *p)
 {
-	struct task_struct *relative;
 	unsigned long free = 0;
 	unsigned state;
 
@@ -4882,19 +4716,7 @@ static void show_task(struct task_struct *p)
 		free = (unsigned long)n - (unsigned long)end_of_stack(p);
 	}
 #endif
-	printk("%5lu %5d %6d ", free, p->pid, p->parent->pid);
-	if ((relative = eldest_child(p)))
-		printk("%5d ", relative->pid);
-	else
-		printk("      ");
-	if ((relative = younger_sibling(p)))
-		printk("%7d", relative->pid);
-	else
-		printk("       ");
-	if ((relative = older_sibling(p)))
-		printk(" %5d", relative->pid);
-	else
-		printk("      ");
+	printk("%5lu %5d %6d", free, p->pid, p->parent->pid);
 	if (!p->mm)
 		printk(" (L-TLB)\n");
 	else