diff options
| author | Gleb Natapov <gleb@redhat.com> | 2011-05-04 16:31:03 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-05-05 23:16:59 -0700 |
| commit | 29ce831000081dd757d3116bf774aafffc4b6b20 (patch) | |
| tree | 0b992d993b02d3479a150e9fc508d110dc45631d | |
| parent | bad6e1393cb505fe17747344a23666464daa3fa7 (diff) | |
rcu: provide rcu_virt_note_context_switch() function.
Provide rcu_virt_note_context_switch() for vitalization use to note
quiescent state during guest entry.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | include/linux/rcutiny.h | 8 | ||||
| -rw-r--r-- | include/linux/rcutree.h | 10 | ||||
| -rw-r--r-- | kernel/rcutree.c | 1 |
3 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 30ebd7c8d874..52b3e0281fd0 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -100,6 +100,14 @@ static inline void rcu_note_context_switch(int cpu) } /* + * Take advantage of the fact that there is only one CPU, which + * allows us to ignore virtualization-based context switches. + */ +static inline void rcu_virt_note_context_switch(int cpu) +{ +} + +/* * Return the number of grace periods. */ static inline long rcu_batches_completed(void) diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 284dad10c55b..e65d06634dd8 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -35,6 +35,16 @@ extern void rcu_note_context_switch(int cpu); extern int rcu_needs_cpu(int cpu); extern void rcu_cpu_stall_reset(void); +/* + * Note a virtualization-based context switch. This is simply a + * wrapper around rcu_note_context_switch(), which allows TINY_RCU + * to save a few bytes. + */ +static inline void rcu_virt_note_context_switch(int cpu) +{ + rcu_note_context_switch(cpu); +} + #ifdef CONFIG_TREE_PREEMPT_RCU extern void exit_rcu(void); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index b2fe2a273df2..54ff7eb92819 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -157,6 +157,7 @@ void rcu_note_context_switch(int cpu) rcu_sched_qs(cpu); rcu_preempt_note_context_switch(cpu); } +EXPORT_SYMBOL_GPL(rcu_note_context_switch); #ifdef CONFIG_NO_HZ DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { |