diff options
| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-03-27 19:02:08 -0400 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-05-02 17:43:23 -0400 |
| commit | 616c310e83b872024271c915c1b9ab505b9efad9 (patch) | |
| tree | 1339bc7b3bef920b4641a5af2f182e9dfa2a6632 /kernel/rcutree.c | |
| parent | 66f75a5d028beaf67c931435fdc3e7823125730c (diff) | |
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 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 1050d6d3922c..61351505ec78 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c | |||
| @@ -192,7 +192,6 @@ void rcu_note_context_switch(int cpu) | |||
| 192 | { | 192 | { |
| 193 | trace_rcu_utilization("Start context switch"); | 193 | trace_rcu_utilization("Start context switch"); |
| 194 | rcu_sched_qs(cpu); | 194 | rcu_sched_qs(cpu); |
| 195 | rcu_preempt_note_context_switch(cpu); | ||
| 196 | trace_rcu_utilization("End context switch"); | 195 | trace_rcu_utilization("End context switch"); |
| 197 | } | 196 | } |
| 198 | EXPORT_SYMBOL_GPL(rcu_note_context_switch); | 197 | EXPORT_SYMBOL_GPL(rcu_note_context_switch); |