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| author |   Paul E. McKenney <paul.mckenney@linaro.org> | 2012-03-27 16:02:08 -0700 |
|---|---|---|
| committer |   Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-05-02 14:43:23 -0700 |
| commit | 616c310e83b872024271c915c1b9ab505b9efad9 (patch) | |
| tree | 1339bc7b3bef920b4641a5af2f182e9dfa2a6632 /include/linux/rcupdate.h | |
| parent | Linux 3.4-rc4 (diff) | |
| download | linux-dev-616c310e83b872024271c915c1b9ab505b9efad9.tar.xz linux-dev-616c310e83b872024271c915c1b9ab505b9efad9.zip | |
rcu: Move PREEMPT_RCU preemption to switch_to() invocation
Currently, PREEMPT_RCU readers are enqueued upon entry to the scheduler.
This is inefficient because enqueuing is required only if there is a
context switch, and entry to the scheduler does not guarantee a context
switch.
The commit therefore moves the enqueuing to immediately precede the
call to switch_to() from the scheduler.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 20fb776a1d4a..bbfe7854a6a6 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -184,6 +184,7 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); +extern void rcu_preempt_note_context_switch(void); extern void rcu_check_callbacks(int cpu, int user); struct notifier_block; extern void rcu_idle_enter(void); |