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Subject[patch 1/8] preempt: Use CONFIG_PREEMPTION where appropriate
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.

Switch the preemption code, scheduler and init task over to use
CONFIG_PREEMPTION.

That's the first step towards RT in that area. The more complex changes are
coming separately.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/asm-generic/preempt.h | 4 ++--
include/linux/preempt.h | 6 +++---
include/linux/sched.h | 6 +++---
init/init_task.c | 2 +-
init/main.c | 2 +-
kernel/sched/core.c | 14 +++++++-------
kernel/sched/fair.c | 2 +-
kernel/sched/sched.h | 4 ++--
8 files changed, 20 insertions(+), 20 deletions(-)

--- a/include/asm-generic/preempt.h
+++ b/include/asm-generic/preempt.h
@@ -78,11 +78,11 @@ static __always_inline bool should_resch
tif_need_resched());
}

-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
extern asmlinkage void preempt_schedule(void);
#define __preempt_schedule() preempt_schedule()
extern asmlinkage void preempt_schedule_notrace(void);
#define __preempt_schedule_notrace() preempt_schedule_notrace()
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */

#endif /* __ASM_PREEMPT_H */
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -182,7 +182,7 @@ do { \

#define preemptible() (preempt_count() == 0 && !irqs_disabled())

-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
#define preempt_enable() \
do { \
barrier(); \
@@ -203,7 +203,7 @@ do { \
__preempt_schedule(); \
} while (0)

-#else /* !CONFIG_PREEMPT */
+#else /* !CONFIG_PREEMPTION */
#define preempt_enable() \
do { \
barrier(); \
@@ -217,7 +217,7 @@ do { \
} while (0)

#define preempt_check_resched() do { } while (0)
-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */

#define preempt_disable_notrace() \
do { \
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1759,7 +1759,7 @@ static inline int test_tsk_need_resched(
* value indicates whether a reschedule was done in fact.
* cond_resched_lock() will drop the spinlock before scheduling,
*/
-#ifndef CONFIG_PREEMPT
+#ifndef CONFIG_PREEMPTION
extern int _cond_resched(void);
#else
static inline int _cond_resched(void) { return 0; }
@@ -1788,12 +1788,12 @@ static inline void cond_resched_rcu(void

/*
* Does a critical section need to be broken due to another
- * task waiting?: (technically does not depend on CONFIG_PREEMPT,
+ * task waiting?: (technically does not depend on CONFIG_PREEMPTION,
* but a general need for low latency)
*/
static inline int spin_needbreak(spinlock_t *lock)
{
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
return spin_is_contended(lock);
#else
return 0;
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -174,7 +174,7 @@ struct task_struct init_task
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.ret_stack = NULL,
#endif
-#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPT)
+#if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION)
.trace_recursion = 0,
#endif
#ifdef CONFIG_LIVEPATCH
--- a/init/main.c
+++ b/init/main.c
@@ -433,7 +433,7 @@ noinline void __ref rest_init(void)

/*
* Enable might_sleep() and smp_processor_id() checks.
- * They cannot be enabled earlier because with CONFIG_PREEMPT=y
+ * They cannot be enabled earlier because with CONFIG_PREEMPTION=y
* kernel_thread() would trigger might_sleep() splats. With
* CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled
* already, but it's stuck on the kthreadd_done completion.
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3581,7 +3581,7 @@ static inline void sched_tick_start(int
static inline void sched_tick_stop(int cpu) { }
#endif

-#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
+#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_TRACE_PREEMPT_TOGGLE))
/*
* If the value passed in is equal to the current preempt count
@@ -3782,7 +3782,7 @@ pick_next_task(struct rq *rq, struct tas
* task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
* called on the nearest possible occasion:
*
- * - If the kernel is preemptible (CONFIG_PREEMPT=y):
+ * - If the kernel is preemptible (CONFIG_PREEMPTION=y):
*
* - in syscall or exception context, at the next outmost
* preempt_enable(). (this might be as soon as the wake_up()'s
@@ -3791,7 +3791,7 @@ pick_next_task(struct rq *rq, struct tas
* - in IRQ context, return from interrupt-handler to
* preemptible context
*
- * - If the kernel is not preemptible (CONFIG_PREEMPT is not set)
+ * - If the kernel is not preemptible (CONFIG_PREEMPTION is not set)
* then at the next:
*
* - cond_resched() call
@@ -4033,7 +4033,7 @@ static void __sched notrace preempt_sche
} while (need_resched());
}

-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
/*
* this is the entry point to schedule() from in-kernel preemption
* off of preempt_enable. Kernel preemptions off return from interrupt
@@ -4105,7 +4105,7 @@ asmlinkage __visible void __sched notrac
}
EXPORT_SYMBOL_GPL(preempt_schedule_notrace);

-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */

/*
* this is the entry point to schedule() from kernel preemption
@@ -5416,7 +5416,7 @@ SYSCALL_DEFINE0(sched_yield)
return 0;
}

-#ifndef CONFIG_PREEMPT
+#ifndef CONFIG_PREEMPTION
int __sched _cond_resched(void)
{
if (should_resched(0)) {
@@ -5433,7 +5433,7 @@ EXPORT_SYMBOL(_cond_resched);
* __cond_resched_lock() - if a reschedule is pending, drop the given lock,
* call schedule, and on return reacquire the lock.
*
- * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
+ * This works OK both with and without CONFIG_PREEMPTION. We do strange low-level
* operations here to prevent schedule() from being called twice (once via
* spin_unlock(), once by hand).
*/
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7376,7 +7376,7 @@ static int detach_tasks(struct lb_env *e
detached++;
env->imbalance -= load;

-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
/*
* NEWIDLE balancing is a source of latency, so preemptible
* kernels will stop after the first task is detached to minimize
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1943,7 +1943,7 @@ unsigned long arch_scale_freq_capacity(i
#endif

#ifdef CONFIG_SMP
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION

static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);

@@ -1995,7 +1995,7 @@ static inline int _double_lock_balance(s
return ret;
}

-#endif /* CONFIG_PREEMPT */
+#endif /* CONFIG_PREEMPTION */

/*
* double_lock_balance - lock the busiest runqueue, this_rq is locked already.

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