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author | Jiri Kosina <jkosina@suse.cz> | 2010-04-23 02:08:44 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-04-23 02:08:44 +0200 |
commit | 6c9468e9eb1252eaefd94ce7f06e1be9b0b641b1 (patch) | |
tree | 797676a336b050bfa1ef879377c07e541b9075d6 /kernel/rcupdate.c | |
parent | UML: Fix compiler warning due to missing task_struct declaration (diff) | |
parent | Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6 (diff) | |
download | linux-6c9468e9eb1252eaefd94ce7f06e1be9b0b641b1.tar.xz linux-6c9468e9eb1252eaefd94ce7f06e1be9b0b641b1.zip |
Merge branch 'master' into for-next
Diffstat (limited to 'kernel/rcupdate.c')
-rw-r--r-- | kernel/rcupdate.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index f1125c1a6321..03a7ea1579f6 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -45,6 +45,7 @@ #include <linux/mutex.h> #include <linux/module.h> #include <linux/kernel_stat.h> +#include <linux/hardirq.h> #ifdef CONFIG_DEBUG_LOCK_ALLOC static struct lock_class_key rcu_lock_key; @@ -66,6 +67,35 @@ EXPORT_SYMBOL_GPL(rcu_sched_lock_map); int rcu_scheduler_active __read_mostly; EXPORT_SYMBOL_GPL(rcu_scheduler_active); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + +int debug_lockdep_rcu_enabled(void) +{ + return rcu_scheduler_active && debug_locks && + current->lockdep_recursion == 0; +} +EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled); + +/** + * rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section? + * + * Check for bottom half being disabled, which covers both the + * CONFIG_PROVE_RCU and not cases. Note that if someone uses + * rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled) + * will show the situation. + * + * Check debug_lockdep_rcu_enabled() to prevent false positives during boot. + */ +int rcu_read_lock_bh_held(void) +{ + if (!debug_lockdep_rcu_enabled()) + return 1; + return in_softirq(); +} +EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held); + +#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ + /* * This function is invoked towards the end of the scheduler's initialization * process. Before this is called, the idle task might contain |