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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-01-22 02:23:15 +0100
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-01-22 02:23:15 +0100
commit19c22c34dcbecb50c24548aa2ff2b07039c26c14 (patch)
tree15793721700c05310952fede97a2585ca1959709 /kernel/sched/idle_task.c
parent[media] az6007: CodingStyle fixes (diff)
parentLinux 3.3-rc1 (diff)
downloadlinux-19c22c34dcbecb50c24548aa2ff2b07039c26c14.tar.xz
linux-19c22c34dcbecb50c24548aa2ff2b07039c26c14.zip
Merge tag 'v3.3-rc1' into staging/for_v3.3
* tag 'v3.3-rc1': (8187 commits) Linux 3.3-rc1 x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits qnx4: don't leak ->BitMap on late failure exits qnx4: reduce the insane nesting in qnx4_checkroot() qnx4: di_fname is an array, for crying out loud... KEYS: Permit key_serial() to be called with a const key pointer keys: fix user_defined key sparse messages ima: fix cred sparse warning uml: fix compile for x86-64 MPILIB: Add a missing ENOMEM check tpm: fix (ACPI S3) suspend regression nvme: fix merge error due to change of 'make_request_fn' fn type xen: using EXPORT_SYMBOL requires including export.h gpio: tps65910: Use correct offset for gpio initialization acpi/apei/einj: Add extensions to EINJ from rev 5.0 of acpi spec intel_idle: Split up and provide per CPU initialization func ACPI processor: Remove unneeded variable passed by acpi_processor_hotadd_init V2 tg3: Fix single-vector MSI-X code openvswitch: Fix multipart datapath dumps. ipv6: fix per device IP snmp counters ...
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 000000000000..91b4c957f289
--- /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,
+};