diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-03-15 14:27:06 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-03-15 14:27:06 +0000 |
| commit | 2d3b5fa3a39d16c880bda3cf2bd9dd6ed5a01f74 (patch) | |
| tree | e20283fe2ed46aa35c8ca5fc1724ba067cd2e2f8 /include/linux/rcupdate.h | |
| parent | 3f17522ce461a31e7ced6311b28fcf5b8a763316 (diff) | |
| parent | 7278a22143b003e9af7b9ca1b5f1c40ae4b55d98 (diff) | |
Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/genesis-2.6
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index a005cac5e30..3024050c82a 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -101,6 +101,11 @@ extern struct lockdep_map rcu_sched_lock_map; # define rcu_read_release_sched() \ lock_release(&rcu_sched_lock_map, 1, _THIS_IP_) +static inline int debug_lockdep_rcu_enabled(void) +{ + return likely(rcu_scheduler_active && debug_locks); +} + /** * rcu_read_lock_held - might we be in RCU read-side critical section? * @@ -108,12 +113,14 @@ extern struct lockdep_map rcu_sched_lock_map; * an RCU read-side critical section. In absence of CONFIG_PROVE_LOCKING, * this assumes we are in an RCU read-side critical section unless it can * prove otherwise. + * + * Check rcu_scheduler_active to prevent false positives during boot. */ static inline int rcu_read_lock_held(void) { - if (debug_locks) - return lock_is_held(&rcu_lock_map); - return 1; + if (!debug_lockdep_rcu_enabled()) + return 1; + return lock_is_held(&rcu_lock_map); } /** @@ -123,12 +130,14 @@ static inline int rcu_read_lock_held(void) * an RCU-bh read-side critical section. In absence of CONFIG_PROVE_LOCKING, * this assumes we are in an RCU-bh read-side critical section unless it can * prove otherwise. + * + * Check rcu_scheduler_active to prevent false positives during boot. */ static inline int rcu_read_lock_bh_held(void) { - if (debug_locks) - return lock_is_held(&rcu_bh_lock_map); - return 1; + if (!debug_lockdep_rcu_enabled()) + return 1; + return lock_is_held(&rcu_bh_lock_map); } /** @@ -139,15 +148,26 @@ static inline int rcu_read_lock_bh_held(void) * this assumes we are in an RCU-sched read-side critical section unless it * can prove otherwise. Note that disabling of preemption (including * disabling irqs) counts as an RCU-sched read-side critical section. + * + * Check rcu_scheduler_active to prevent false positives during boot. */ +#ifdef CONFIG_PREEMPT static inline int rcu_read_lock_sched_held(void) { int lockdep_opinion = 0; + if (!debug_lockdep_rcu_enabled()) + return 1; if (debug_locks) lockdep_opinion = lock_is_held(&rcu_sched_lock_map); - return lockdep_opinion || preempt_count() != 0 || !rcu_scheduler_active; + return lockdep_opinion || preempt_count() != 0; +} +#else /* #ifdef CONFIG_PREEMPT */ +static inline int rcu_read_lock_sched_held(void) +{ + return 1; } +#endif /* #else #ifdef CONFIG_PREEMPT */ #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ @@ -168,10 +188,17 @@ static inline int rcu_read_lock_bh_held(void) return 1; } +#ifdef CONFIG_PREEMPT static inline int rcu_read_lock_sched_held(void) { - return preempt_count() != 0 || !rcu_scheduler_active; + return !rcu_scheduler_active || preempt_count() != 0; +} +#else /* #ifdef CONFIG_PREEMPT */ +static inline int rcu_read_lock_sched_held(void) +{ + return 1; } +#endif /* #else #ifdef CONFIG_PREEMPT */ #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ @@ -188,7 +215,7 @@ static inline int rcu_read_lock_sched_held(void) */ #define rcu_dereference_check(p, c) \ ({ \ - if (debug_locks && !(c)) \ + if (debug_lockdep_rcu_enabled() && !(c)) \ lockdep_rcu_dereference(__FILE__, __LINE__); \ rcu_dereference_raw(p); \ }) |