[PATCH] pi-futex: scheduler support for pi
Add framework to boost/unboost the priority of RT tasks.
This consists of:
- caching the 'normal' priority in ->normal_prio
- providing a functions to set/get the priority of the task
- make sched_setscheduler() aware of boosting
The effective_prio() cleanups also fix a priority-calculation bug pointed out
by Andrey Gelman, in set_user_nice().
has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andrey Gelman <agelman@012.net.il>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index e127ef7..678c1a9 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -87,6 +87,7 @@
.lock_depth = -1, \
.prio = MAX_PRIO-20, \
.static_prio = MAX_PRIO-20, \
+ .normal_prio = MAX_PRIO-20, \
.policy = SCHED_NORMAL, \
.cpus_allowed = CPU_MASK_ALL, \
.mm = NULL, \
@@ -122,6 +123,7 @@
.journal_info = NULL, \
.cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
.fs_excl = ATOMIC_INIT(0), \
+ .pi_lock = SPIN_LOCK_UNLOCKED, \
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0bc81a1..6f16764 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -495,8 +495,11 @@
#define MAX_PRIO (MAX_RT_PRIO + 40)
-#define rt_task(p) (unlikely((p)->prio < MAX_RT_PRIO))
+#define rt_prio(prio) unlikely((prio) < MAX_RT_PRIO)
+#define rt_task(p) rt_prio((p)->prio)
#define batch_task(p) (unlikely((p)->policy == SCHED_BATCH))
+#define has_rt_policy(p) \
+ unlikely((p)->policy != SCHED_NORMAL && (p)->policy != SCHED_BATCH)
/*
* Some day this will be a full-fledged user tracking system..
@@ -725,7 +728,7 @@
#endif
#endif
int load_weight; /* for niceness load balancing purposes */
- int prio, static_prio;
+ int prio, static_prio, normal_prio;
struct list_head run_list;
prio_array_t *array;
@@ -852,6 +855,9 @@
/* Protection of (de-)allocation: mm, files, fs, tty, keyrings */
spinlock_t alloc_lock;
+ /* Protection of the PI data structures: */
+ spinlock_t pi_lock;
+
#ifdef CONFIG_DEBUG_MUTEXES
/* mutex deadlock detection */
struct mutex_waiter *blocked_on;
@@ -1018,6 +1024,17 @@
#endif
extern void sched_idle_next(void);
+
+#ifdef CONFIG_RT_MUTEXES
+extern int rt_mutex_getprio(task_t *p);
+extern void rt_mutex_setprio(task_t *p, int prio);
+#else
+static inline int rt_mutex_getprio(task_t *p)
+{
+ return p->normal_prio;
+}
+#endif
+
extern void set_user_nice(task_t *p, long nice);
extern int task_prio(const task_t *p);
extern int task_nice(const task_t *p);
