From b2c0710c464ede15e1fc52fb1e7ee9ba54cea186 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 9 Sep 2010 13:40:39 -0700 Subject: rcu: move TINY_RCU from softirq to kthread If RCU priority boosting is to be meaningful, callback invocation must be boosted in addition to preempted RCU readers. Otherwise, in presence of CPU real-time threads, the grace period ends, but the callbacks don't get invoked. If the callbacks don't get invoked, the associated memory doesn't get freed, so the system is still subject to OOM. But it is not reasonable to priority-boost RCU_SOFTIRQ, so this commit moves the callback invocations to a kthread, which can be boosted easily. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- include/linux/rcutiny.h | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'include/linux/rcutiny.h') diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 13877cb..ea025a6 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -27,7 +27,9 @@ #include -#define rcu_init_sched() do { } while (0) +static inline void rcu_init(void) +{ +} #ifdef CONFIG_TINY_RCU @@ -125,16 +127,12 @@ static inline void rcu_cpu_stall_reset(void) } #ifdef CONFIG_DEBUG_LOCK_ALLOC - extern int rcu_scheduler_active __read_mostly; extern void rcu_scheduler_starting(void); - #else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ - static inline void rcu_scheduler_starting(void) { } - #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ #endif /* __LINUX_RCUTINY_H */ -- cgit v1.1 From 7b27d5475f86186914e54e4a6bb994e9a985337b Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Thu, 21 Oct 2010 11:29:05 +0800 Subject: rcu,cleanup: move synchronize_sched_expedited() out of sched.c The first version of synchronize_sched_expedited() used the migration code in the scheduler, and was therefore implemented in kernel/sched.c. However, the more recent version of this code no longer uses the migration code, so this commit moves it to the main RCU source files. Signed-off-by: Lai Jiangshan Signed-off-by: Paul E. McKenney --- include/linux/rcutiny.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/rcutiny.h') diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index ea025a6..30ebd7c 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -60,6 +60,11 @@ static inline void synchronize_rcu_bh_expedited(void) synchronize_sched(); } +static inline void synchronize_sched_expedited(void) +{ + synchronize_sched(); +} + #ifdef CONFIG_TINY_RCU static inline void rcu_preempt_note_context_switch(void) -- cgit v1.1