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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-04-02 16:17:17 -0700 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-05-10 11:08:34 -0700 |
commit | bbad937983147c017c25406860287cb94da9af7c (patch) | |
tree | 57311598c360b92b189c7ec337146e4bc779c73d /kernel/rcutree.c | |
parent | 25502a6c13745f4650cc59322bd198194f55e796 (diff) | |
download | kernel_samsung_crespo-bbad937983147c017c25406860287cb94da9af7c.zip kernel_samsung_crespo-bbad937983147c017c25406860287cb94da9af7c.tar.gz kernel_samsung_crespo-bbad937983147c017c25406860287cb94da9af7c.tar.bz2 |
rcu: slim down rcutiny by removing rcu_scheduler_active and friends
TINY_RCU does not need rcu_scheduler_active unless CONFIG_DEBUG_LOCK_ALLOC.
So conditionally compile rcu_scheduler_active in order to slim down
rcutiny a bit more. Also gets rid of an EXPORT_SYMBOL_GPL, which is
responsible for most of the slimming.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r-- | kernel/rcutree.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e336313..3623f8e 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -46,6 +46,7 @@ #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/time.h> +#include <linux/kernel_stat.h> #include "rcutree.h" @@ -80,6 +81,9 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data); struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state); DEFINE_PER_CPU(struct rcu_data, rcu_bh_data); +int rcu_scheduler_active __read_mostly; +EXPORT_SYMBOL_GPL(rcu_scheduler_active); + /* * Return true if an RCU grace period is in progress. The ACCESS_ONCE()s * permit this function to be invoked without holding the root rcu_node @@ -1784,6 +1788,21 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, } /* + * This function is invoked towards the end of the scheduler's initialization + * process. Before this is called, the idle task might contain + * RCU read-side critical sections (during which time, this idle + * task is booting the system). After this function is called, the + * idle tasks are prohibited from containing RCU read-side critical + * sections. This function also enables RCU lockdep checking. + */ +void rcu_scheduler_starting(void) +{ + WARN_ON(num_online_cpus() != 1); + WARN_ON(nr_context_switches() > 0); + rcu_scheduler_active = 1; +} + +/* * Compute the per-level fanout, either using the exact fanout specified * or balancing the tree, depending on CONFIG_RCU_FANOUT_EXACT. */ |