sched: Isolate preempt counting in its own config option

Create a new CONFIG_PREEMPT_COUNT that handles the inc/dec
of preempt count offset independently. So that the offset
can be updated by preempt_disable() and preempt_enable()
even without the need for CONFIG_PREEMPT beeing set.

This prepares to make CONFIG_DEBUG_SPINLOCK_SLEEP working
with !CONFIG_PREEMPT where it currently doesn't detect
code that sleeps inside explicit preemption disabled
sections.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
This commit is contained in:
Frederic Weisbecker
2011-06-08 01:13:27 +02:00
parent 2da8c8bc44
commit bdd4e85dc3
8 changed files with 33 additions and 22 deletions

View File

@@ -239,7 +239,7 @@ extern int rcu_read_lock_bh_held(void);
* Check debug_lockdep_rcu_enabled() to prevent false positives during boot
* and while lockdep is disabled.
*/
#ifdef CONFIG_PREEMPT
#ifdef CONFIG_PREEMPT_COUNT
static inline int rcu_read_lock_sched_held(void)
{
int lockdep_opinion = 0;
@@ -250,12 +250,12 @@ static inline int rcu_read_lock_sched_held(void)
lockdep_opinion = lock_is_held(&rcu_sched_lock_map);
return lockdep_opinion || preempt_count() != 0 || irqs_disabled();
}
#else /* #ifdef CONFIG_PREEMPT */
#else /* #ifdef CONFIG_PREEMPT_COUNT */
static inline int rcu_read_lock_sched_held(void)
{
return 1;
}
#endif /* #else #ifdef CONFIG_PREEMPT */
#endif /* #else #ifdef CONFIG_PREEMPT_COUNT */
#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
@@ -276,17 +276,17 @@ static inline int rcu_read_lock_bh_held(void)
return 1;
}
#ifdef CONFIG_PREEMPT
#ifdef CONFIG_PREEMPT_COUNT
static inline int rcu_read_lock_sched_held(void)
{
return preempt_count() != 0 || irqs_disabled();
}
#else /* #ifdef CONFIG_PREEMPT */
#else /* #ifdef CONFIG_PREEMPT_COUNT */
static inline int rcu_read_lock_sched_held(void)
{
return 1;
}
#endif /* #else #ifdef CONFIG_PREEMPT */
#endif /* #else #ifdef CONFIG_PREEMPT_COUNT */
#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */