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

Pull scheduler fixes from Ingo Molnar:
 "Four misc fixes: each was deemed serious enough to warrant v3.15
  inclusion"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix tg_set_cfs_bandwidth() deadlock on rq->lock
  sched/dl: Fix race in dl_task_timer()
  sched: Fix sched_policy < 0 comparison
  sched/numa: Fix use of spin_{un}lock_irq() when interrupts are disabled

4 files changed, 20 insertions, 12 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0a7251678982..084d17f89139 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3685,7 +3685,7 @@ SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr,
         if (retval)
                 return retval;
 
-        if (attr.sched_policy < 0)
+        if ((int)attr.sched_policy < 0)
                 return -EINVAL;
 
         rcu_read_lock();
@@ -7751,8 +7751,7 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
         /* restart the period timer (if active) to handle new period expiry */
         if (runtime_enabled && cfs_b->timer_active) {
                 /* force a reprogram */
-                cfs_b->timer_active = 0;
-                __start_cfs_bandwidth(cfs_b);
+                __start_cfs_bandwidth(cfs_b, true);
         }
         raw_spin_unlock_irq(&cfs_b->lock);
 
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 800e99b99075..14bc348ba3b4 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -513,9 +513,17 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
                                                      struct sched_dl_entity,
                                                      dl_timer);
         struct task_struct *p = dl_task_of(dl_se);
-        struct rq *rq = task_rq(p);
+        struct rq *rq;
+again:
+        rq = task_rq(p);
         raw_spin_lock(&rq->lock);
 
+        if (rq != task_rq(p)) {
+                /* Task was moved, retrying. */
+                raw_spin_unlock(&rq->lock);
+                goto again;
+        }
+
         /*
          * We need to take care of a possible races here. In fact, the
          * task might have changed its scheduling policy to something
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0fdb96de81a5..8cbe2d2c16de 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1707,18 +1707,19 @@ no_join:
 void task_numa_free(struct task_struct *p)
 {
         struct numa_group *grp = p->numa_group;
-        int i;
         void *numa_faults = p->numa_faults_memory;
+        unsigned long flags;
+        int i;
 
         if (grp) {
-                spin_lock_irq(&grp->lock);
+                spin_lock_irqsave(&grp->lock, flags);
                 for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
                         grp->faults[i] -= p->numa_faults_memory[i];
                 grp->total_faults -= p->total_numa_faults;
 
                 list_del(&p->numa_entry);
                 grp->nr_tasks--;
-                spin_unlock_irq(&grp->lock);
+                spin_unlock_irqrestore(&grp->lock, flags);
                 rcu_assign_pointer(p->numa_group, NULL);
                 put_numa_group(grp);
         }
@@ -3129,7 +3130,7 @@ static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq)
                  */
                 if (!cfs_b->timer_active) {
                         __refill_cfs_bandwidth_runtime(cfs_b);
-                        __start_cfs_bandwidth(cfs_b);
+                        __start_cfs_bandwidth(cfs_b, false);
                 }
 
                 if (cfs_b->runtime > 0) {
@@ -3308,7 +3309,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
         raw_spin_lock(&cfs_b->lock);
         list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
         if (!cfs_b->timer_active)
-                __start_cfs_bandwidth(cfs_b);
+                __start_cfs_bandwidth(cfs_b, false);
         raw_spin_unlock(&cfs_b->lock);
 }
 
@@ -3690,7 +3691,7 @@ static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 }
 
 /* requires cfs_b->lock, may release to reprogram timer */
-void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force)
 {
         /*
          * The timer may be active because we're trying to set a new bandwidth
@@ -3705,7 +3706,7 @@ void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
                 cpu_relax();
                 raw_spin_lock(&cfs_b->lock);
                 /* if someone else restarted the timer then we're done */
-                if (cfs_b->timer_active)
+                if (!force && cfs_b->timer_active)
                         return;
         }
 
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 456e492a3dca..369b4d663c42 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -278,7 +278,7 @@ extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
 
 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
-extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
+extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force);
 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
 
 extern void free_rt_sched_group(struct task_group *tg);