From bd3bff9e20f454b242d979ec2f9a4dca0d5fa06f Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 12 May 2008 21:20:41 +0200
Subject: [PATCH] sched: add latency tracer callbacks to the scheduler
add 3 lightweight callbacks to the tracer backend.
zero impact if tracing is turned off.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/sched.h | 26 ++++++++++++++++++++++++++
kernel/sched.c | 3 +++
2 files changed, 29 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5395a6176f4b..717cab8a0c83 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2117,6 +2117,32 @@ static inline void arch_pick_mmap_layout(struct mm_struct *mm)
}
#endif
+#ifdef CONFIG_CONTEXT_SWITCH_TRACER
+extern void
+ftrace_ctx_switch(struct task_struct *prev, struct task_struct *next);
+#else
+static inline void
+ftrace_ctx_switch(struct task_struct *prev, struct task_struct *next)
+{
+}
+#endif
+
+#ifdef CONFIG_SCHED_TRACER
+extern void
+ftrace_wake_up_task(struct task_struct *wakee, struct task_struct *curr);
+extern void
+ftrace_wake_up_new_task(struct task_struct *wakee, struct task_struct *curr);
+#else
+static inline void
+ftrace_wake_up_task(struct task_struct *wakee, struct task_struct *curr)
+{
+}
+static inline void
+ftrace_wake_up_new_task(struct task_struct *wakee, struct task_struct *curr)
+{
+}
+#endif
+
extern long sched_setaffinity(pid_t pid, const cpumask_t *new_mask);
extern long sched_getaffinity(pid_t pid, cpumask_t *mask);
diff --git a/kernel/sched.c b/kernel/sched.c
index cfa222a91539..463dcdb36ef8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2467,6 +2467,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
out_activate:
#endif /* CONFIG_SMP */
+ ftrace_wake_up_task(p, rq->curr);
schedstat_inc(p, se.nr_wakeups);
if (sync)
schedstat_inc(p, se.nr_wakeups_sync);
@@ -2611,6 +2612,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
p->sched_class->task_new(rq, p);
inc_nr_running(rq);
}
+ ftrace_wake_up_new_task(p, rq->curr);
check_preempt_curr(rq, p);
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
@@ -2783,6 +2785,7 @@ context_switch(struct rq *rq, struct task_struct *prev,
struct mm_struct *mm, *oldmm;
prepare_task_switch(rq, prev, next);
+ ftrace_ctx_switch(prev, next);
mm = next->mm;
oldmm = prev->active_mm;
/*
--
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