Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Simplify sys_sched_rr_get_interval() system call
  sched: Fix potential NULL derference of doms_cur
  sched: Fix raciness in runqueue_is_locked()
  sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair()
  sched: Remove unneeded indentation in sched_fair.c::place_entity()

5 files changed, 73 insertions, 49 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index faf4d463bbff..830967e18285 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -681,15 +681,9 @@ inline void update_rq_clock(struct rq *rq)
  * This interface allows printk to be called with the runqueue lock
  * held and know whether or not it is OK to wake up the klogd.
  */
-int runqueue_is_locked(void)
+int runqueue_is_locked(int cpu)
 {
-        int cpu = get_cpu();
-        struct rq *rq = cpu_rq(cpu);
-        int ret;
-
-        ret = spin_is_locked(&rq->lock);
-        put_cpu();
-        return ret;
+        return spin_is_locked(&cpu_rq(cpu)->lock);
 }
 
 /*
@@ -6825,23 +6819,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
         if (retval)
                 goto out_unlock;
 
-        /*
-         * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER
-         * tasks that are on an otherwise idle runqueue:
-         */
-        time_slice = 0;
-        if (p->policy == SCHED_RR) {
-                time_slice = DEF_TIMESLICE;
-        } else if (p->policy != SCHED_FIFO) {
-                struct sched_entity *se = &p->se;
-                unsigned long flags;
-                struct rq *rq;
+        time_slice = p->sched_class->get_rr_interval(p);
 
-                rq = task_rq_lock(p, &flags);
-                if (rq->cfs.load.weight)
-                        time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
-                task_rq_unlock(rq, &flags);
-        }
         read_unlock(&tasklist_lock);
         jiffies_to_timespec(time_slice, &t);
         retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
@@ -9171,6 +9150,7 @@ void __init sched_init_smp(void)
         cpumask_var_t non_isolated_cpus;
 
         alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
+        alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
 
 #if defined(CONFIG_NUMA)
         sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
@@ -9202,7 +9182,6 @@ void __init sched_init_smp(void)
         sched_init_granularity();
         free_cpumask_var(non_isolated_cpus);
 
-        alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
         init_sched_rt_class();
 }
 #else
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 990b188803ce..ecc637a0d591 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -710,31 +710,28 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
         if (initial && sched_feat(START_DEBIT))
                 vruntime += sched_vslice(cfs_rq, se);
 
-        if (!initial) {
-                /* sleeps upto a single latency don't count. */
-                if (sched_feat(FAIR_SLEEPERS)) {
-                        unsigned long thresh = sysctl_sched_latency;
+        /* sleeps up to a single latency don't count. */
+        if (!initial && sched_feat(FAIR_SLEEPERS)) {
+                unsigned long thresh = sysctl_sched_latency;
 
-                        /*
-                         * Convert the sleeper threshold into virtual time.
-                         * SCHED_IDLE is a special sub-class.  We care about
-                         * fairness only relative to other SCHED_IDLE tasks,
-                         * all of which have the same weight.
-                         */
-                        if (sched_feat(NORMALIZED_SLEEPER) &&
-                                        (!entity_is_task(se) ||
-                                         task_of(se)->policy != SCHED_IDLE))
-                                thresh = calc_delta_fair(thresh, se);
+                /*
+                 * Convert the sleeper threshold into virtual time.
+                 * SCHED_IDLE is a special sub-class.  We care about
+                 * fairness only relative to other SCHED_IDLE tasks,
+                 * all of which have the same weight.
+                 */
+                if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) ||
+                                 task_of(se)->policy != SCHED_IDLE))
+                        thresh = calc_delta_fair(thresh, se);
 
-                        /*
-                         * Halve their sleep time's effect, to allow
-                         * for a gentler effect of sleepers:
-                         */
-                        if (sched_feat(GENTLE_FAIR_SLEEPERS))
-                                thresh >>= 1;
+                /*
+                 * Halve their sleep time's effect, to allow
+                 * for a gentler effect of sleepers:
+                 */
+                if (sched_feat(GENTLE_FAIR_SLEEPERS))
+                        thresh >>= 1;
 
-                        vruntime -= thresh;
-                }
+                vruntime -= thresh;
         }
 
         /* ensure we never gain time by being placed backwards. */
@@ -1343,7 +1340,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
         int sync = wake_flags & WF_SYNC;
 
         if (sd_flag & SD_BALANCE_WAKE) {
-                if (sched_feat(AFFINE_WAKEUPS))
+                if (sched_feat(AFFINE_WAKEUPS) &&
+                    cpumask_test_cpu(cpu, &p->cpus_allowed))
                         want_affine = 1;
                 new_cpu = prev_cpu;
         }
@@ -1941,6 +1939,25 @@ static void moved_group_fair(struct task_struct *p)
 }
 #endif
 
+unsigned int get_rr_interval_fair(struct task_struct *task)
+{
+        struct sched_entity *se = &task->se;
+        unsigned long flags;
+        struct rq *rq;
+        unsigned int rr_interval = 0;
+
+        /*
+         * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
+         * idle runqueue:
+         */
+        rq = task_rq_lock(task, &flags);
+        if (rq->cfs.load.weight)
+                rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
+        task_rq_unlock(rq, &flags);
+
+        return rr_interval;
+}
+
 /*
  * All the scheduling class methods:
  */
@@ -1969,6 +1986,8 @@ static const struct sched_class fair_sched_class = {
         .prio_changed           = prio_changed_fair,
         .switched_to            = switched_to_fair,
 
+        .get_rr_interval        = get_rr_interval_fair,
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
         .moved_group            = moved_group_fair,
 #endif
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index a8b448af004b..b133a28fcde3 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -97,6 +97,11 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p,
                 check_preempt_curr(rq, p, 0);
 }
 
+unsigned int get_rr_interval_idle(struct task_struct *task)
+{
+        return 0;
+}
+
 /*
  * Simple, special scheduling class for the per-CPU idle tasks:
  */
@@ -122,6 +127,8 @@ static const struct sched_class idle_sched_class = {
         .set_curr_task          = set_curr_task_idle,
         .task_tick              = task_tick_idle,
 
+        .get_rr_interval        = get_rr_interval_idle,
+
         .prio_changed           = prio_changed_idle,
         .switched_to            = switched_to_idle,
 
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 13de7126a6ab..a4d790cddb19 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1734,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq)
         dequeue_pushable_task(rq, p);
 }
 
+unsigned int get_rr_interval_rt(struct task_struct *task)
+{
+        /*
+         * Time slice is 0 for SCHED_FIFO tasks
+         */
+        if (task->policy == SCHED_RR)
+                return DEF_TIMESLICE;
+        else
+                return 0;
+}
+
 static const struct sched_class rt_sched_class = {
         .next                   = &fair_sched_class,
         .enqueue_task           = enqueue_task_rt,
@@ -1762,6 +1773,8 @@ static const struct sched_class rt_sched_class = {
         .set_curr_task          = set_curr_task_rt,
         .task_tick              = task_tick_rt,
 
+        .get_rr_interval        = get_rr_interval_rt,
+
         .prio_changed           = prio_changed_rt,
         .switched_to            = switched_to_rt,
 };
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 861308072d28..a35925d222ba 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -268,12 +268,18 @@ static DEFINE_SPINLOCK(tracing_start_lock);
  */
 void trace_wake_up(void)
 {
+        int cpu;
+
+        if (trace_flags & TRACE_ITER_BLOCK)
+                return;
         /*
          * The runqueue_is_locked() can fail, but this is the best we
          * have for now:
          */
-        if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
+        cpu = get_cpu();
+        if (!runqueue_is_locked(cpu))
                 wake_up(&trace_wait);
+        put_cpu();
 }
 
 static int __init set_buf_size(char *str)