From b560d8ad8583803978aaaeba50ef29dc8e97a610 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 21 Aug 2009 22:08:51 -0700 Subject: [PATCH] rcu: Expunge lingering references to CONFIG_CLASSIC_RCU, optimize on !SMP A couple of references to CONFIG_CLASSIC_RCU have survived. Although these are harmless, it is past time for them to go. The one in hardirq.h is strictly a readability problem. The two in pagemap.h appear to disable a !SMP performance optimization (which this patch re-enables). This does raise the issue as to whether pagemap.h should really be referring to the CPU implementation. Long term, I intend to make the RCU implementation driven by CONFIG_PREEMPT, at which point these should change from defined(CONFIG_TREE_RCU) to !defined(CONFIG_PREEMPT). In the meantime, is there something else that could be done in pagemap.h? Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <20090822050851.GA8414@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- include/linux/hardirq.h | 4 ++-- include/linux/pagemap.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 8246c697863d..330cb31bb496 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -132,7 +132,7 @@ static inline void account_system_vtime(struct task_struct *tsk) } #endif -#if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU) +#if defined(CONFIG_NO_HZ) extern void rcu_irq_enter(void); extern void rcu_irq_exit(void); extern void rcu_nmi_enter(void); @@ -142,7 +142,7 @@ extern void rcu_nmi_exit(void); # define rcu_irq_exit() do { } while (0) # define rcu_nmi_enter() do { } while (0) # define rcu_nmi_exit() do { } while (0) -#endif /* #if defined(CONFIG_NO_HZ) && !defined(CONFIG_CLASSIC_RCU) */ +#endif /* #if defined(CONFIG_NO_HZ) */ /* * It is safe to do non-atomic ops on ->hardirq_context, diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index aec3252afcf5..ed5d7501e181 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -132,7 +132,7 @@ static inline int page_cache_get_speculative(struct page *page) { VM_BUG_ON(in_interrupt()); -#if !defined(CONFIG_SMP) && defined(CONFIG_CLASSIC_RCU) +#if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU) # ifdef CONFIG_PREEMPT VM_BUG_ON(!in_atomic()); # endif @@ -170,7 +170,7 @@ static inline int page_cache_add_speculative(struct page *page, int count) { VM_BUG_ON(in_interrupt()); -#if !defined(CONFIG_SMP) && defined(CONFIG_CLASSIC_RCU) +#if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU) # ifdef CONFIG_PREEMPT VM_BUG_ON(!in_atomic()); # endif