Messages in this thread Patch in this message |  | | | Date | Tue, 24 Apr 2012 21:36:35 +0900 | | From | Minho Ban <> | | Subject | [RFC/PATCH] Prevent wasting time to find out get_parent_ip |
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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 <tglx@linutronix.de> Signed-off-by: Minho Ban <mhban@samsung.com> --- 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
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