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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-13 14:43:01 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-13 14:43:01 -0800 |
commit | 4e3eaddd142e2142c048c5052a0a9d2604fccfc6 (patch) | |
tree | 5bc45a286502e54e790c54948f22364c5afd9d89 /include/linux/rcupdate.h | |
parent | 8655e7e3ddec60603c4f6c14cdf642e2ba198df8 (diff) | |
parent | b97c4bc16734a2e597dac7f91ee9eb78f4aeef9a (diff) | |
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Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
locking: Make sparse work with inline spinlocks and rwlocks
x86/mce: Fix RCU lockdep splats
rcu: Increase RCU CPU stall timeouts if PROVE_RCU
ftrace: Replace read_barrier_depends() with rcu_dereference_raw()
rcu: Suppress RCU lockdep warnings during early boot
rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare()
rcu: Suppress __mpol_dup() false positive from RCU lockdep
rcu: Make rcu_read_lock_sched_held() handle !PREEMPT
rcu: Add control variables to lockdep_rcu_dereference() diagnostics
rcu, cgroup: Relax the check in task_subsys_state() as early boot is now handled by lockdep-RCU
rcu: Use wrapper function instead of exporting tasklist_lock
sched, rcu: Fix rcu_dereference() for RCU-lockdep
rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use
rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU
x86/gart: Unexport gart_iommu_aperture
Fix trivial conflicts in kernel/trace/ftrace.c
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 a005cac..3024050 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); \ }) |