Messages in this thread Patch in this message | | | Date | Wed, 9 Mar 2011 17:16:04 -0500 | From | Joe Korty <> | Subject | [PATCH 3/4] jrcu: tap might_resched() |
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jrcu: tap into might_resched.
All places where the voluntary preemption patches have marked as safe to context switch are also known rcu quiescent points.
Not fundamentally needed, accelerates rcu batching.
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Index: b/include/linux/kernel.h =================================================================== --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -114,11 +114,18 @@ struct completion; struct pt_regs; struct user; +/* cannot bring in linux/rcupdate.h at this point */ +#ifdef CONFIG_JRCU +extern void rcu_note_might_resched(void); +#else +#define rcu_note_might_resched() +#endif /*JRCU */ + #ifdef CONFIG_PREEMPT_VOLUNTARY extern int _cond_resched(void); -# define might_resched() _cond_resched() +# define might_resched() do { _cond_resched(); rcu_note_might_resched(); } while (0) #else -# define might_resched() do { } while (0) +# define might_resched() do { rcu_note_might_resched(); } while (0) #endif #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP Index: b/include/linux/jrcu.h =================================================================== --- a/include/linux/jrcu.h +++ b/include/linux/jrcu.h @@ -71,6 +71,8 @@ extern void rcu_note_context_switch(int #define rcu_sched_qs rcu_note_context_switch #define rcu_bh_qs rcu_note_context_switch +extern void rcu_note_might_resched(void); + extern void rcu_scheduler_starting(void); extern int rcu_scheduler_active __read_mostly; Index: b/kernel/jrcu.c =================================================================== --- a/kernel/jrcu.c +++ b/kernel/jrcu.c @@ -166,6 +166,16 @@ void rcu_note_context_switch(int cpu) rcu_eob(cpu); } +void rcu_note_might_resched(void) +{ + unsigned long flags; + + raw_local_irq_save(flags); + rcu_eob(rcu_cpu()); + raw_local_irq_restore(flags); +} +EXPORT_SYMBOL(rcu_note_might_resched); + void rcu_barrier(void) { struct rcu_synchronize rcu;
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