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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 /kernel/sched | |
| parent | 66f75a5d028beaf67c931435fdc3e7823125730c (diff) | |
| download | blackbird-obmc-linux-616c310e83b872024271c915c1b9ab505b9efad9.tar.gz blackbird-obmc-linux-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 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4603b9d8f30a..5d89eb93f7e4 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2083,6 +2083,7 @@ context_switch(struct rq *rq, struct task_struct *prev, #endif /* Here we just switch the register state and the stack. */ + rcu_switch_from(prev); switch_to(prev, next, prev); barrier(); |
