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rcu: Eliminate unneeded function wrapping

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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 <paulmck@linux.vnet.ibm.com>
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 <mingo@elte.hu>
This commit is contained in:
Paul E. McKenney 2009-11-22 08:53:49 -08:00 committed by Ingo Molnar
parent b668c9cf3e
commit 9f680ab414
5 changed files with 15 additions and 40 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
include/linux/rcutiny.h
View file

@ -38,7 +38,6 @@ void rcu_bh_qs(int cpu);
#define rcu_init_sched() do { } while (0) #define rcu_init_sched() do { } while (0)
extern void rcu_check_callbacks(int cpu, int user); extern void rcu_check_callbacks(int cpu, int user);
extern void __rcu_init(void);
/* /*
* Return the number of grace periods. * Return the number of grace periods.
@ -69,7 +68,6 @@ static inline void synchronize_rcu_bh_expedited(void)
} }
struct notifier_block; struct notifier_block;
extern int rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu);
#ifdef CONFIG_NO_HZ #ifdef CONFIG_NO_HZ

3
include/linux/rcutree.h
View file

@ -34,8 +34,6 @@ struct notifier_block;
extern void rcu_sched_qs(int cpu); extern void rcu_sched_qs(int cpu);
extern void rcu_bh_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_needs_cpu(int cpu);
extern int rcu_expedited_torture_stats(char *page); extern int rcu_expedited_torture_stats(char *page);
@ -83,7 +81,6 @@ static inline void synchronize_rcu_bh_expedited(void)
synchronize_sched_expedited(); synchronize_sched_expedited();
} }
extern void __rcu_init(void);
extern void rcu_check_callbacks(int cpu, int user); extern void rcu_check_callbacks(int cpu, int user);
extern long rcu_batches_completed(void); extern long rcu_batches_completed(void);

22
kernel/rcupdate.c
View file

@ -161,28 +161,6 @@ EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
#endif /* #ifndef CONFIG_TINY_RCU */ #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) void rcu_scheduler_starting(void)
{ {
WARN_ON(num_online_cpus() != 1); WARN_ON(num_online_cpus() != 1);

11
kernel/rcutiny.c
View file

@ -177,15 +177,6 @@ static void rcu_process_callbacks(struct softirq_action *unused)
__rcu_process_callbacks(&rcu_bh_ctrlblk); __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 * Wait for a grace period to elapse. But it is illegal to invoke
* synchronize_sched() from within an RCU read-side critical section. * 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); EXPORT_SYMBOL_GPL(rcu_barrier_sched);
void __rcu_init(void) void __init rcu_init(void)
{ {
open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
} }

15
kernel/rcutree.c
View file

@ -1644,7 +1644,7 @@ static void __cpuinit rcu_online_cpu(int cpu)
/* /*
* Handle CPU online/offline notification events. * Handle CPU online/offline notification events.
*/ */
int __cpuinit rcu_cpu_notify(struct notifier_block *self, static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu) unsigned long action, void *hcpu)
{ {
long cpu = (long)hcpu; long cpu = (long)hcpu;
@ -1781,8 +1781,10 @@ do { \
} \ } \
} while (0) } while (0)
void __init __rcu_init(void) void __init rcu_init(void)
{ {
int i;
rcu_bootup_announce(); rcu_bootup_announce();
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n"); 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_FLAVOR(&rcu_bh_state, rcu_bh_data);
__rcu_init_preempt(); __rcu_init_preempt();
open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); 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" #include "rcutree_plugin.h"