Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index cdefcf7..71d9a9c 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2192,7 +2192,7 @@ static inline void post_schedule(struct rq *rq)
  * schedule_tail - first thing a freshly forked thread must call.
  * @prev: the thread we just switched away from.
  */
-asmlinkage void schedule_tail(struct task_struct *prev)
+asmlinkage __visible void schedule_tail(struct task_struct *prev)
        __releases(rq->lock)
 {
        struct rq *rq = this_rq();
@@ -2747,7 +2747,7 @@ static inline void sched_submit_work(struct task_struct *tsk)
                blk_schedule_flush_plug(tsk);
 }
 
-asmlinkage void __sched schedule(void)
+asmlinkage __visible void __sched schedule(void)
 {
        struct task_struct *tsk = current;
 
@@ -2757,7 +2757,7 @@ asmlinkage void __sched schedule(void)
 EXPORT_SYMBOL(schedule);
 
 #ifdef CONFIG_CONTEXT_TRACKING
-asmlinkage void __sched schedule_user(void)
+asmlinkage __visible void __sched schedule_user(void)
 {
        /*
         * If we come here after a random call to set_need_resched(),
@@ -2789,7 +2789,7 @@ void __sched schedule_preempt_disabled(void)
  * off of preempt_enable. Kernel preemptions off return from interrupt
  * occur there and call schedule directly.
  */
-asmlinkage void __sched notrace preempt_schedule(void)
+asmlinkage __visible void __sched notrace preempt_schedule(void)
 {
        /*
         * If there is a non-zero preempt_count or interrupts are disabled,
@@ -2819,7 +2819,7 @@ EXPORT_SYMBOL(preempt_schedule);
  * Note, that this is called and return with irqs disabled. This will
  * protect us against recursive calling from irq.
  */
-asmlinkage void __sched preempt_schedule_irq(void)
+asmlinkage __visible void __sched preempt_schedule_irq(void)
 {
        enum ctx_state prev_state;
 
@@ -3195,17 +3195,40 @@ __getparam_dl(struct task_struct *p, struct sched_attr *attr)
  * We ask for the deadline not being zero, and greater or equal
  * than the runtime, as well as the period of being zero or
  * greater than deadline. Furthermore, we have to be sure that
- * user parameters are above the internal resolution (1us); we
- * check sched_runtime only since it is always the smaller one.
+ * user parameters are above the internal resolution of 1us (we
+ * check sched_runtime only since it is always the smaller one) and
+ * below 2^63 ns (we have to check both sched_deadline and
+ * sched_period, as the latter can be zero).
  */
 static bool
 __checkparam_dl(const struct sched_attr *attr)
 {
-       return attr && attr->sched_deadline != 0 &&
-               (attr->sched_period == 0 ||
-               (s64)(attr->sched_period   - attr->sched_deadline) >= 0) &&
-               (s64)(attr->sched_deadline - attr->sched_runtime ) >= 0  &&
-               attr->sched_runtime >= (2 << (DL_SCALE - 1));
+       /* deadline != 0 */
+       if (attr->sched_deadline == 0)
+               return false;
+
+       /*
+        * Since we truncate DL_SCALE bits, make sure we're at least
+        * that big.
+        */
+       if (attr->sched_runtime < (1ULL << DL_SCALE))
+               return false;
+
+       /*
+        * Since we use the MSB for wrap-around and sign issues, make
+        * sure it's not set (mind that period can be equal to zero).
+        */
+       if (attr->sched_deadline & (1ULL << 63) ||
+           attr->sched_period & (1ULL << 63))
+               return false;
+
+       /* runtime <= deadline <= period (if period != 0) */
+       if ((attr->sched_period != 0 &&
+            attr->sched_period < attr->sched_deadline) ||
+           attr->sched_deadline < attr->sched_runtime)
+               return false;
+
+       return true;
 }
 
 /*
@@ -3713,7 +3736,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
  */
 SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
 {
-       struct sched_param lp;
+       struct sched_param lp = { .sched_priority = 0 };
        struct task_struct *p;
        int retval;
 
@@ -3730,11 +3753,8 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
        if (retval)
                goto out_unlock;
 
-       if (task_has_dl_policy(p)) {
-               retval = -EINVAL;
-               goto out_unlock;
-       }
-       lp.sched_priority = p->rt_priority;
+       if (task_has_rt_policy(p))
+               lp.sched_priority = p->rt_priority;
        rcu_read_unlock();
 
        /*
@@ -4064,6 +4084,7 @@ static void __cond_resched(void)
 
 int __sched _cond_resched(void)
 {
+       rcu_cond_resched();
        if (should_resched()) {
                __cond_resched();
                return 1;
@@ -4082,15 +4103,18 @@ EXPORT_SYMBOL(_cond_resched);
  */
 int __cond_resched_lock(spinlock_t *lock)
 {
+       bool need_rcu_resched = rcu_should_resched();
        int resched = should_resched();
        int ret = 0;
 
        lockdep_assert_held(lock);
 
-       if (spin_needbreak(lock) || resched) {
+       if (spin_needbreak(lock) || resched || need_rcu_resched) {
                spin_unlock(lock);
                if (resched)
                        __cond_resched();
+               else if (unlikely(need_rcu_resched))
+                       rcu_resched();
                else
                        cpu_relax();
                ret = 1;
@@ -4104,6 +4128,7 @@ int __sched __cond_resched_softirq(void)
 {
        BUG_ON(!in_softirq());
 
+       rcu_cond_resched();  /* BH disabled OK, just recording QSes. */
        if (should_resched()) {
                local_bh_enable();
                __cond_resched();
@@ -5056,7 +5081,6 @@ static int sched_cpu_active(struct notifier_block *nfb,
                                      unsigned long action, void *hcpu)
 {
        switch (action & ~CPU_TASKS_FROZEN) {
-       case CPU_STARTING:
        case CPU_DOWN_FAILED:
                set_cpu_active((long)hcpu, true);
                return NOTIFY_OK;