From 2f33b512a5460578f6cf11d7b7867bed53157c7c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 17 Nov 2013 18:25:48 -0800 Subject: [PATCH] rcu: Optimize rcu_is_nocb_cpu() for RCU_NOCB_CPU_ALL If CONFIG_RCU_NOCB_CPU_ALL=y, then rcu_is_nocb_cpu() will always return true, however, the current version nevertheless checks rcu_nocb_mask. This commit therefore creates a static inline implementation of rcu_is_nocb_cpu() that unconditionally returns true when CONFIG_RCU_NOCB_CPU_ALL=y. Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- include/linux/rcupdate.h | 6 ++++-- kernel/rcu/tree_plugin.h | 2 ++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 72bf3a01a4ee..281c90f8989e 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -1015,11 +1015,13 @@ 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)) -#ifdef CONFIG_RCU_NOCB_CPU +#if defined(CONFIG_RCU_NOCB_CPU_ALL) +static inline bool rcu_is_nocb_cpu(int cpu) { return true; } +#elif defined(CONFIG_RCU_NOCB_CPU) bool rcu_is_nocb_cpu(int cpu); #else static inline bool rcu_is_nocb_cpu(int cpu) { return false; } -#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ +#endif /* Only for use by adaptive-ticks code. */ diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 6e2ef4b2b920..39a50b918bff 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2101,6 +2101,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp) init_waitqueue_head(&rnp->nocb_gp_wq[1]); } +#ifndef CONFIG_RCU_NOCB_CPU_ALL /* Is the specified CPU a no-CPUs CPU? */ bool rcu_is_nocb_cpu(int cpu) { @@ -2108,6 +2109,7 @@ bool rcu_is_nocb_cpu(int cpu) return cpumask_test_cpu(cpu, rcu_nocb_mask); return false; } +#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */ /* * Enqueue the specified string of rcu_head structures onto the specified -- 2.39.5