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

[karo-tx-linux.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 249e37dc02c862fc98dd2fab55d14135404f0f16..ea8f49ae00626771a6497f50e5670b7f129f8a8c 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -26,6 +26,7 @@
  *              Thomas Gleixner, Mike Kravetz
  */
 
+#include <linux/kasan.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/nmi.h>
@@ -319,20 +320,6 @@ static inline void init_hrtick(void)
 }
 #endif /* CONFIG_SCHED_HRTICK */
 
-/*
- * cmpxchg based fetch_or, macro so it works for different integer types
- */
-#define fetch_or(ptr, val)                                             \
-({     typeof(*(ptr)) __old, __val = *(ptr);                           \
-       for (;;) {                                                      \
-               __old = cmpxchg((ptr), __val, __val | (val));           \
-               if (__old == __val)                                     \
-                       break;                                          \
-               __val = __old;                                          \
-       }                                                               \
-       __old;                                                          \
-})
-
 #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
 /*
  * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
@@ -581,31 +568,36 @@ static inline bool got_nohz_idle_kick(void)
 #endif /* CONFIG_NO_HZ_COMMON */
 
 #ifdef CONFIG_NO_HZ_FULL
-bool sched_can_stop_tick(void)
+bool sched_can_stop_tick(struct rq *rq)
 {
+       int fifo_nr_running;
+
+       /* Deadline tasks, even if single, need the tick */
+       if (rq->dl.dl_nr_running)
+               return false;
+
        /*
-        * FIFO realtime policy runs the highest priority task. Other runnable
-        * tasks are of a lower priority. The scheduler tick does nothing.
+        * FIFO realtime policy runs the highest priority task (after DEADLINE).
+        * Other runnable tasks are of a lower priority. The scheduler tick
+        * isn't needed.
         */
-       if (current->policy == SCHED_FIFO)
+       fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
+       if (fifo_nr_running)
                return true;
 
        /*
         * Round-robin realtime tasks time slice with other tasks at the same
-        * realtime priority. Is this task the only one at this priority?
+        * realtime priority.
         */
-       if (current->policy == SCHED_RR) {
-               struct sched_rt_entity *rt_se = &current->rt;
-
-               return list_is_singular(&rt_se->run_list);
+       if (rq->rt.rr_nr_running) {
+               if (rq->rt.rr_nr_running == 1)
+                       return true;
+               else
+                       return false;
        }
 
-       /*
-        * More than one running task need preemption.
-        * nr_running update is assumed to be visible
-        * after IPI is sent from wakers.
-        */
-       if (this_rq()->nr_running > 1)
+       /* Normal multitasking need periodic preemption checks */
+       if (rq->cfs.nr_running > 1)
                return false;
 
        return true;
@@ -5021,6 +5013,8 @@ void init_idle(struct task_struct *idle, int cpu)
        idle->state = TASK_RUNNING;
        idle->se.exec_start = sched_clock();
 
+       kasan_unpoison_task_stack(idle);
+
 #ifdef CONFIG_SMP
        /*
         * Its possible that init_idle() gets called multiple times on a task,
@@ -5440,16 +5434,6 @@ static int sched_cpu_active(struct notifier_block *nfb,
                set_cpu_rq_start_time();
                return NOTIFY_OK;
 
-       case CPU_ONLINE:
-               /*
-                * At this point a starting CPU has marked itself as online via
-                * set_cpu_online(). But it might not yet have marked itself
-                * as active, which is essential from here on.
-                */
-               set_cpu_active(cpu, true);
-               stop_machine_unpark(cpu);
-               return NOTIFY_OK;
-
        case CPU_DOWN_FAILED:
                set_cpu_active(cpu, true);
                return NOTIFY_OK;