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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-07-02 07:08:42 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-07-02 11:39:19 -0700 |
| commit | cba6d0d64ee53772b285d0c0c288deefbeaf7775 (patch) | |
| tree | b2d3de62d15a77d23708c1af6f188c86f0d87fb9 /include/linux/rcutiny.h | |
| parent | 6887a4131da3adaab011613776d865f4bcfb5678 (diff) | |
| download | blackbird-op-linux-cba6d0d64ee53772b285d0c0c288deefbeaf7775.tar.gz blackbird-op-linux-cba6d0d64ee53772b285d0c0c288deefbeaf7775.zip | |
Revert "rcu: Move PREEMPT_RCU preemption to switch_to() invocation"
This reverts commit 616c310e83b872024271c915c1b9ab505b9efad9.
(Move PREEMPT_RCU preemption to switch_to() invocation).
Testing by Sasha Levin <levinsasha928@gmail.com> showed that this
can result in deadlock due to invoking the scheduler when one of
the runqueue locks is held. Because this commit was simply a
performance optimization, revert it.
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Diffstat (limited to 'include/linux/rcutiny.h')
| -rw-r--r-- | include/linux/rcutiny.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 854dc4c5c271..4e56a9c69a35 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -87,6 +87,10 @@ static inline void kfree_call_rcu(struct rcu_head *head, #ifdef CONFIG_TINY_RCU +static inline void rcu_preempt_note_context_switch(void) +{ +} + static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) { *delta_jiffies = ULONG_MAX; @@ -95,6 +99,7 @@ static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) #else /* #ifdef CONFIG_TINY_RCU */ +void rcu_preempt_note_context_switch(void); int rcu_preempt_needs_cpu(void); static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) @@ -108,6 +113,7 @@ static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) static inline void rcu_note_context_switch(int cpu) { rcu_sched_qs(cpu); + rcu_preempt_note_context_switch(); } /* |
