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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-05-22 22:10:24 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-07-02 12:34:24 -0700 |
| commit | 62fde6edf12b60fddb13a3f0a779c8be0bb7447e (patch) | |
| tree | 2fa26e28ce311acb29c60f1595235240be6e7d97 /include/linux/rcupdate.h | |
| parent | 28f5c693d03530eb15c5354f758b789189b98c37 (diff) | |
| download | blackbird-obmc-linux-62fde6edf12b60fddb13a3f0a779c8be0bb7447e.tar.gz blackbird-obmc-linux-62fde6edf12b60fddb13a3f0a779c8be0bb7447e.zip | |
rcu: Make __call_rcu() handle invocation from idle
Although __call_rcu() is handled correctly when called from a momentary
non-idle period, if it is called on a CPU that RCU believes to be idle
on RCU_FAST_NO_HZ kernels, the callback might be indefinitely postponed.
This commit therefore ensures that RCU is aware of the new callback and
has a chance to force the CPU out of dyntick-idle mode when a new callback
is posted.
Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 31568c734525..26f6417f0264 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -256,6 +256,10 @@ static inline void destroy_rcu_head_on_stack(struct rcu_head *head) } #endif /* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ +#if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SMP) +extern int rcu_is_cpu_idle(void); +#endif /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_SMP) */ + #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PROVE_RCU) bool rcu_lockdep_current_cpu_online(void); #else /* #if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_PROVE_RCU) */ @@ -267,15 +271,6 @@ static inline bool rcu_lockdep_current_cpu_online(void) #ifdef CONFIG_DEBUG_LOCK_ALLOC -#ifdef CONFIG_PROVE_RCU -extern int rcu_is_cpu_idle(void); -#else /* !CONFIG_PROVE_RCU */ -static inline int rcu_is_cpu_idle(void) -{ - return 0; -} -#endif /* else !CONFIG_PROVE_RCU */ - static inline void rcu_lock_acquire(struct lockdep_map *map) { lock_acquire(map, 0, 0, 2, 1, NULL, _THIS_IP_); |
