From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753885Ab2DXMgj (ORCPT ); Tue, 24 Apr 2012 08:36:39 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:53552 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753577Ab2DXMgi (ORCPT ); Tue, 24 Apr 2012 08:36:38 -0400 X-AuditID: cbfee61a-b7b8eae00000534b-9a-4f969e54e970 Message-id: <4F969E53.9080307@samsung.com> Date: Tue, 24 Apr 2012 21:36:35 +0900 From: Minho Ban User-Agent: Mozilla/5.0 (X11; Linux i686; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-version: 1.0 To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Steven Rostedt , Frederic Weisbecker , Peter Zijlstra , Paul Turner , Thomas Gleixner , Hidetoshi Seto , "Paul E. McKenney" , Josh Triplett Subject: [RFC/PATCH] Prevent wasting time to find out get_parent_ip Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Brightmail-Tracker: AAAAAA== X-TM-AS-MML: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org trace_preempt_on/off looks empty if PREEMPT_TRACER is off. But actually it is spending time to find out get_parent_ip(even CALLER_ADDR for some ARCH) which is in argument. This seems not fair for those who expect to do nothing but increase or decrease count. Cc: Thomas Gleixner Signed-off-by: Minho Ban --- include/linux/ftrace.h | 3 --- kernel/sched/core.c | 5 ++++- kernel/softirq.c | 3 ++- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 72a6cab..7cd11fe 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -484,9 +484,6 @@ static inline void __ftrace_enabled_restore(int enabled) #ifdef CONFIG_PREEMPT_TRACER extern void trace_preempt_on(unsigned long a0, unsigned long a1); extern void trace_preempt_off(unsigned long a0, unsigned long a1); -#else - static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { } - static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { } #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4603b9d..efdd5a0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3068,8 +3068,10 @@ void __kprobes add_preempt_count(int val) DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= PREEMPT_MASK - 10); #endif +#ifdef CONFIG_PREEMPT_TRACER if (preempt_count() == val) trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); +#endif } EXPORT_SYMBOL(add_preempt_count); @@ -3088,9 +3090,10 @@ void __kprobes sub_preempt_count(int val) !(preempt_count() & PREEMPT_MASK))) return; #endif - +#ifdef CONFIG_PREEMPT_TRACER if (preempt_count() == val) trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); +#endif preempt_count() -= val; } EXPORT_SYMBOL(sub_preempt_count); diff --git a/kernel/softirq.c b/kernel/softirq.c index 671f959..e7c8336 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -112,9 +112,10 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) if (softirq_count() == cnt) trace_softirqs_off(ip); raw_local_irq_restore(flags); - +#ifdef CONFIG_PREEMPT_TRACER if (preempt_count() == cnt) trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); +#endif } #else /* !CONFIG_TRACE_IRQFLAGS */ static inline void __local_bh_disable(unsigned long ip, unsigned int cnt) -- 1.7.5.4