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authorSteven Rostedt <srostedt@redhat.com>2008-05-12 21:20:42 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-23 20:32:54 +0200
commit6cd8a4bb2f97527a9ceb30bc77ea4e959c6a95e3 (patch)
tree845af8f3c7f8956b4f3591759a0d67248af243a2 /include/linux/preempt.h
parent81d68a96a39844853b37f20cc8282d9b65b78ef3 (diff)
ftrace: trace preempt off critical timings
Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/linux/preempt.h')
-rw-r--r--include/linux/preempt.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 36b03d50bf40..72b1a10a59b6 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -10,7 +10,7 @@
#include <linux/linkage.h>
#include <linux/list.h>
-#ifdef CONFIG_DEBUG_PREEMPT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
extern void add_preempt_count(int val);
extern void sub_preempt_count(int val);
#else