On Mon, Feb 17, 2014 at 01:40:26PM -0800, Paul E. McKenney wrote: > From: "Paul E. McKenney" <[email protected]> > > If CONFIG_RCU_NOCB_CPU_ALL=y, then rcu_needs_cpu() will always > return false, however, the current version nevertheless checks > for RCU callbacks. This commit therefore creates a static inline > implementation of rcu_needs_cpu() that unconditionally returns false > when CONFIG_RCU_NOCB_CPU_ALL=y. > > Signed-off-by: Paul E. McKenney <[email protected]>
Reviewed-by: Josh Triplett <[email protected]> > --- > include/linux/rcupdate.h | 9 +++++++++ > include/linux/rcutiny.h | 6 ------ > include/linux/rcutree.h | 2 ++ > kernel/rcu/tree.c | 2 +- > kernel/rcu/tree_plugin.h | 4 ++++ > 5 files changed, 16 insertions(+), 7 deletions(-) > > diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h > index 92365b1fede4..da77ef26b4ac 100644 > --- a/include/linux/rcupdate.h > +++ b/include/linux/rcupdate.h > @@ -1015,6 +1015,15 @@ static inline notrace void > rcu_read_unlock_sched_notrace(void) > #define kfree_rcu(ptr, rcu_head) \ > __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) > > +#if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL) > + > +static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) > +{ > + *delta_jiffies = ULONG_MAX; > + return 0; > +} > +#endif /* #if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL) */ > + > #ifdef CONFIG_RCU_NOCB_CPU > #ifdef CONFIG_RCU_NOCB_CPU_ALL > static inline bool rcu_is_nocb_cpu(int cpu) { return true; } > diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h > index 6f01771b571c..9524903487d0 100644 > --- a/include/linux/rcutiny.h > +++ b/include/linux/rcutiny.h > @@ -68,12 +68,6 @@ static inline void kfree_call_rcu(struct rcu_head *head, > call_rcu(head, func); > } > > -static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) > -{ > - *delta_jiffies = ULONG_MAX; > - return 0; > -} > - > static inline void rcu_note_context_switch(int cpu) > { > rcu_sched_qs(cpu); > diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h > index 72137ee8c603..81198c84e268 100644 > --- a/include/linux/rcutree.h > +++ b/include/linux/rcutree.h > @@ -31,7 +31,9 @@ > #define __LINUX_RCUTREE_H > > void rcu_note_context_switch(int cpu); > +#ifndef CONFIG_RCU_NOCB_CPU_ALL > int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies); > +#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ > void rcu_cpu_stall_reset(void); > > /* > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index b3d116cd072d..c2c8234a0291 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2880,7 +2880,7 @@ static int rcu_pending(int cpu) > * non-NULL, store an indication of whether all callbacks are lazy. > * (If there are no callbacks, all of them are deemed to be lazy.) > */ > -static int rcu_cpu_has_callbacks(int cpu, bool *all_lazy) > +static int __maybe_unused rcu_cpu_has_callbacks(int cpu, bool *all_lazy) > { > bool al = true; > bool hc = false; > diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h > index 39a50b918bff..820b06aefbee 100644 > --- a/kernel/rcu/tree_plugin.h > +++ b/kernel/rcu/tree_plugin.h > @@ -1586,11 +1586,13 @@ static void rcu_prepare_kthreads(int cpu) > * Because we not have RCU_FAST_NO_HZ, just check whether this CPU needs > * any flavor of RCU. > */ > +#ifndef CONFIG_RCU_NOCB_CPU_ALL > int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies) > { > *delta_jiffies = ULONG_MAX; > return rcu_cpu_has_callbacks(cpu, NULL); > } > +#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ > > /* > * Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up > @@ -1696,6 +1698,7 @@ static bool rcu_try_advance_all_cbs(void) > * > * The caller must have disabled interrupts. > */ > +#ifndef CONFIG_RCU_NOCB_CPU_ALL > int rcu_needs_cpu(int cpu, unsigned long *dj) > { > struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu); > @@ -1726,6 +1729,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj) > } > return 0; > } > +#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ > > /* > * Prepare a CPU for idle from an RCU perspective. The first major task > -- > 1.8.1.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
