From 9f680ab41485edfdc96331b70afa7513aa0a7720 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 22 Nov 2009 08:53:49 -0800 Subject: [PATCH] rcu: Eliminate unneeded function wrapping The functions rcu_init() is a wrapper for __rcu_init(), and also sets up the CPU-hotplug notifier for rcu_barrier_cpu_hotplug(). But TINY_RCU doesn't need CPU-hotplug notification, and the rcu_barrier_cpu_hotplug() is a simple wrapper for rcu_cpu_notify(). So push rcu_init() out to kernel/rcutree.c and kernel/rcutiny.c and get rid of the wrapper function rcu_barrier_cpu_hotplug(). Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12589088302320-git-send-email-> Signed-off-by: Ingo Molnar --- include/linux/rcutiny.h | 2 -- include/linux/rcutree.h | 3 --- kernel/rcupdate.c | 22 ---------------------- kernel/rcutiny.c | 11 +---------- kernel/rcutree.c | 17 ++++++++++++++--- 5 files changed, 15 insertions(+), 40 deletions(-) diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 2c1fe8373e71..a3b6272af2dd 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -38,7 +38,6 @@ void rcu_bh_qs(int cpu); #define rcu_init_sched() do { } while (0) extern void rcu_check_callbacks(int cpu, int user); -extern void __rcu_init(void); /* * Return the number of grace periods. @@ -69,7 +68,6 @@ static inline void synchronize_rcu_bh_expedited(void) } struct notifier_block; -extern int rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu); #ifdef CONFIG_NO_HZ diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 9642c6bcb399..111a65257350 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -34,8 +34,6 @@ struct notifier_block; extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); -extern int rcu_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu); extern int rcu_needs_cpu(int cpu); extern int rcu_expedited_torture_stats(char *page); @@ -83,7 +81,6 @@ static inline void synchronize_rcu_bh_expedited(void) synchronize_sched_expedited(); } -extern void __rcu_init(void); extern void rcu_check_callbacks(int cpu, int user); extern long rcu_batches_completed(void); diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 7625f207f65e..eb6b534db318 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -161,28 +161,6 @@ EXPORT_SYMBOL_GPL(synchronize_rcu_bh); #endif /* #ifndef CONFIG_TINY_RCU */ -static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - return rcu_cpu_notify(self, action, hcpu); -} - -void __init rcu_init(void) -{ - int i; - - __rcu_init(); - cpu_notifier(rcu_barrier_cpu_hotplug, 0); - - /* - * We don't need protection against CPU-hotplug here because - * this is called early in boot, before either interrupts - * or the scheduler are operational. - */ - for_each_online_cpu(i) - rcu_barrier_cpu_hotplug(NULL, CPU_UP_PREPARE, (void *)(long)i); -} - void rcu_scheduler_starting(void) { WARN_ON(num_online_cpus() != 1); diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index b33ec3aa377a..9f6d9ff2572c 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -177,15 +177,6 @@ static void rcu_process_callbacks(struct softirq_action *unused) __rcu_process_callbacks(&rcu_bh_ctrlblk); } -/* - * Null function to handle CPU being onlined. Longer term, we want to - * make TINY_RCU avoid using rcupdate.c, but later... - */ -int rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) -{ - return NOTIFY_OK; -} - /* * Wait for a grace period to elapse. But it is illegal to invoke * synchronize_sched() from within an RCU read-side critical section. @@ -285,7 +276,7 @@ void rcu_barrier_sched(void) } EXPORT_SYMBOL_GPL(rcu_barrier_sched); -void __rcu_init(void) +void __init rcu_init(void) { open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); } diff --git a/kernel/rcutree.c b/kernel/rcutree.c index b79bfcd28e95..e3d3bbddbcd5 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1644,8 +1644,8 @@ static void __cpuinit rcu_online_cpu(int cpu) /* * Handle CPU online/offline notification events. */ -int __cpuinit rcu_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) +static int __cpuinit rcu_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) { long cpu = (long)hcpu; @@ -1781,8 +1781,10 @@ do { \ } \ } while (0) -void __init __rcu_init(void) +void __init rcu_init(void) { + int i; + rcu_bootup_announce(); #ifdef CONFIG_RCU_CPU_STALL_DETECTOR printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n"); @@ -1791,6 +1793,15 @@ void __init __rcu_init(void) RCU_INIT_FLAVOR(&rcu_bh_state, rcu_bh_data); __rcu_init_preempt(); open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); + + /* + * We don't need protection against CPU-hotplug here because + * this is called early in boot, before either interrupts + * or the scheduler are operational. + */ + cpu_notifier(rcu_cpu_notify, 0); + for_each_online_cpu(i) + rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)i); } #include "rcutree_plugin.h" -- 2.30.2