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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2011-12-19 19:23:15 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2011-12-19 19:23:15 +0100
commit612ef28a045efadb3a98d4492ead7806a146485d (patch)
tree05621c87b37e91c27b06d450d76adffe97ce9666 /kernel/sched/idle_task.c
parentc3e0ef9a298e028a82ada28101ccd5cf64d209ee (diff)
parent07cde2608a3b5c66515363f1b53623b1536b9785 (diff)
downloadolio-linux-3.10-612ef28a045efadb3a98d4492ead7806a146485d.tar.xz
olio-linux-3.10-612ef28a045efadb3a98d4492ead7806a146485d.zip
Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into cputime-tip
Conflicts: drivers/cpufreq/cpufreq_conservative.c drivers/cpufreq/cpufreq_ondemand.c drivers/macintosh/rack-meter.c fs/proc/stat.c fs/proc/uptime.c kernel/sched/core.c
Diffstat (limited to 'kernel/sched/idle_task.c')
-rw-r--r--kernel/sched/idle_task.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
new file mode 100644
index 00000000000..91b4c957f28
--- /dev/null
+++ b/kernel/sched/idle_task.c
@@ -0,0 +1,99 @@
+#include "sched.h"
+
+/*
+ * idle-task scheduling class.
+ *
+ * (NOTE: these are not related to SCHED_IDLE tasks which are
+ * handled in sched_fair.c)
+ */
+
+#ifdef CONFIG_SMP
+static int
+select_task_rq_idle(struct task_struct *p, int sd_flag, int flags)
+{
+ return task_cpu(p); /* IDLE tasks as never migrated */
+}
+#endif /* CONFIG_SMP */
+/*
+ * Idle tasks are unconditionally rescheduled:
+ */
+static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags)
+{
+ resched_task(rq->idle);
+}
+
+static struct task_struct *pick_next_task_idle(struct rq *rq)
+{
+ schedstat_inc(rq, sched_goidle);
+ calc_load_account_idle(rq);
+ return rq->idle;
+}
+
+/*
+ * It is not legal to sleep in the idle task - print a warning
+ * message if some code attempts to do it:
+ */
+static void
+dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags)
+{
+ raw_spin_unlock_irq(&rq->lock);
+ printk(KERN_ERR "bad: scheduling from the idle thread!\n");
+ dump_stack();
+ raw_spin_lock_irq(&rq->lock);
+}
+
+static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
+{
+}
+
+static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
+{
+}
+
+static void set_curr_task_idle(struct rq *rq)
+{
+}
+
+static void switched_to_idle(struct rq *rq, struct task_struct *p)
+{
+ BUG();
+}
+
+static void
+prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio)
+{
+ BUG();
+}
+
+static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task)
+{
+ return 0;
+}
+
+/*
+ * Simple, special scheduling class for the per-CPU idle tasks:
+ */
+const struct sched_class idle_sched_class = {
+ /* .next is NULL */
+ /* no enqueue/yield_task for idle tasks */
+
+ /* dequeue is not valid, we print a debug message there: */
+ .dequeue_task = dequeue_task_idle,
+
+ .check_preempt_curr = check_preempt_curr_idle,
+
+ .pick_next_task = pick_next_task_idle,
+ .put_prev_task = put_prev_task_idle,
+
+#ifdef CONFIG_SMP
+ .select_task_rq = select_task_rq_idle,
+#endif
+
+ .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,
+};