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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2013-11-17 19:27:16 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-02-17 16:03:09 -0800
commitffa83fb565fbc397cbafb4b71fd1cce276d4c3b6 (patch)
treec849b1ea3517d6853b7b4cd386a682187e314f09 /include/linux
parent2f33b512a5460578f6cf11d7b7867bed53157c7c (diff)
downloadlinux-ffa83fb565fbc397cbafb4b71fd1cce276d4c3b6.tar.gz
linux-ffa83fb565fbc397cbafb4b71fd1cce276d4c3b6.tar.xz
rcu: Optimize rcu_needs_cpu() for RCU_NOCB_CPU_ALL
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 <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/rcupdate.h8
-rw-r--r--include/linux/rcutiny.h6
-rw-r--r--include/linux/rcutree.h2
3 files changed, 10 insertions, 6 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 281c90f8989e..5f7d5f410d50 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -1015,6 +1015,14 @@ 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) */
+
#if defined(CONFIG_RCU_NOCB_CPU_ALL)
static inline bool rcu_is_nocb_cpu(int cpu) { return true; }
#elif defined(CONFIG_RCU_NOCB_CPU)
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);
/*