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| author | Carsten Emde <Carsten.Emde@osadl.org> | 2009-09-15 02:20:37 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2009-09-15 22:09:27 +0200 |
| commit | cc2fa4463d673896b9904c4142c6377d0d1d93e6 (patch) | |
| tree | 3be6139de0e1a65f685064d1c80f687736440c4f /init | |
| parent | edc1a1c366af0d1c755f159b3ac503812e166173 (diff) | |
| download | lwn-cc2fa4463d673896b9904c4142c6377d0d1d93e6.tar.gz lwn-cc2fa4463d673896b9904c4142c6377d0d1d93e6.zip | |
tracing: Add histograms of potential and effective wakeup latencies
Resuscitated and enhanced the kernel latency histograms provided
originally by Yi Yang and adapted and converted by Steven Rostedt.
Latency histograms in the current version
- can be enabled online and independently
- have virtually no performance penalty when configured but not enabled
- have very little performance penalty when enabled
- use already available wakeup and switch tracepoints
- give corresponding results with the related tracer
- allow to record wakeup latency histograms of a single process
- record the process where the highest wakeup latency occurred
- are documented in Documentation/trace/histograms.txt
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4AAEDDD5.4040505@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'init')
| -rw-r--r-- | init/main.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/init/main.c b/init/main.c index 6ddf35d55822..bdbdaab0469e 100644 --- a/init/main.c +++ b/init/main.c @@ -936,7 +936,7 @@ static int __init kernel_init(void * unused) WARN_ON(irqs_disabled()); #endif -#define DEBUG_COUNT (defined(CONFIG_DEBUG_RT_MUTEXES) + defined(CONFIG_IRQSOFF_TRACER) + defined(CONFIG_PREEMPT_TRACER) + defined(CONFIG_STACK_TRACER) + defined(CONFIG_WAKEUP_LATENCY_HIST) + defined(CONFIG_DEBUG_SLAB) + defined(CONFIG_DEBUG_PAGEALLOC) + defined(CONFIG_LOCKDEP) + (defined(CONFIG_FTRACE) - defined(CONFIG_FTRACE_MCOUNT_RECORD))) +#define DEBUG_COUNT (defined(CONFIG_DEBUG_RT_MUTEXES) + defined(CONFIG_IRQSOFF_TRACER) + defined(CONFIG_PREEMPT_TRACER) + defined(CONFIG_STACK_TRACER) + defined(CONFIG_INTERRUPT_OFF_HIST) + defined(CONFIG_PREEMPT_OFF_HIST) + defined(CONFIG_WAKEUP_LATENCY_HIST) + defined(CONFIG_DEBUG_SLAB) + defined(CONFIG_DEBUG_PAGEALLOC) + defined(CONFIG_LOCKDEP) + (defined(CONFIG_FTRACE) - defined(CONFIG_FTRACE_MCOUNT_RECORD))) #if DEBUG_COUNT > 0 printk(KERN_ERR "*****************************************************************************\n"); @@ -956,9 +956,15 @@ static int __init kernel_init(void * unused) #ifdef CONFIG_PREEMPT_TRACER printk(KERN_ERR "* CONFIG_PREEMPT_TRACER *\n"); #endif -#ifdef CONFIG_FTRACE +#if defined(CONFIG_FTRACE) && !defined(CONFIG_FTRACE_MCOUNT_RECORD) printk(KERN_ERR "* CONFIG_FTRACE *\n"); #endif +#ifdef CONFIG_INTERRUPT_OFF_HIST + printk(KERN_ERR "* CONFIG_INTERRUPT_OFF_HIST *\n"); +#endif +#ifdef CONFIG_PREEMPT_OFF_HIST + printk(KERN_ERR "* CONFIG_PREEMPT_OFF_HIST *\n"); +#endif #ifdef CONFIG_WAKEUP_LATENCY_HIST printk(KERN_ERR "* CONFIG_WAKEUP_LATENCY_HIST *\n"); #endif |