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Commit bf1af3a8 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'tip/perf/urgent' of... 

Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
parents 0de4b34d 868baf07

include/linux/ftrace.h

+2 −0
Original line number Diff line number Diff line
@@ -428,6 +428,7 @@ extern void unregister_ftrace_graph(void); 


extern void ftrace_graph_init_task(struct task_struct *t);

extern void ftrace_graph_exit_task(struct task_struct *t);

extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);



static inline int task_curr_ret_stack(struct task_struct *t)

{
@@ -451,6 +452,7 @@ static inline void unpause_graph_tracing(void) 


static inline void ftrace_graph_init_task(struct task_struct *t) { }

static inline void ftrace_graph_exit_task(struct task_struct *t) { }

static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }



static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,

			  trace_func_graph_ent_t entryfunc)

kernel/sched.c

+1 −1
Original line number Diff line number Diff line
@@ -5550,7 +5550,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) 
	 * The idle tasks have their own, simple scheduling class:

	 */

	idle->sched_class = &idle_sched_class;

	ftrace_graph_init_task(idle);

	ftrace_graph_init_idle_task(idle, cpu);

}



/*

kernel/trace/ftrace.c

+45 −7
Original line number Diff line number Diff line
@@ -3328,7 +3328,7 @@ static int start_graph_tracing(void) 
	/* The cpu_boot init_task->ret_stack will never be freed */

	for_each_online_cpu(cpu) {

		if (!idle_task(cpu)->ret_stack)

			ftrace_graph_init_task(idle_task(cpu));

			ftrace_graph_init_idle_task(idle_task(cpu), cpu);

	}



	do {
@@ -3418,6 +3418,49 @@ void unregister_ftrace_graph(void) 
	mutex_unlock(&ftrace_lock);

}



static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);



static void

graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)

{

	atomic_set(&t->tracing_graph_pause, 0);

	atomic_set(&t->trace_overrun, 0);

	t->ftrace_timestamp = 0;

	/* make curr_ret_stack visable before we add the ret_stack */

	smp_wmb();

	t->ret_stack = ret_stack;

}



/*

 * Allocate a return stack for the idle task. May be the first

 * time through, or it may be done by CPU hotplug online.

 */

void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)

{

	t->curr_ret_stack = -1;

	/*

	 * The idle task has no parent, it either has its own

	 * stack or no stack at all.

	 */

	if (t->ret_stack)

		WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));



	if (ftrace_graph_active) {

		struct ftrace_ret_stack *ret_stack;



		ret_stack = per_cpu(idle_ret_stack, cpu);

		if (!ret_stack) {

			ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH

					    * sizeof(struct ftrace_ret_stack),

					    GFP_KERNEL);

			if (!ret_stack)

				return;

			per_cpu(idle_ret_stack, cpu) = ret_stack;

		}

		graph_init_task(t, ret_stack);

	}

}



/* Allocate a return stack for newly created task */

void ftrace_graph_init_task(struct task_struct *t)

{
@@ -3433,12 +3476,7 @@ void ftrace_graph_init_task(struct task_struct *t) 
				GFP_KERNEL);

		if (!ret_stack)

			return;

		atomic_set(&t->tracing_graph_pause, 0);

		atomic_set(&t->trace_overrun, 0);

		t->ftrace_timestamp = 0;

		/* make curr_ret_stack visable before we add the ret_stack */

		smp_wmb();

		t->ret_stack = ret_stack;

		graph_init_task(t, ret_stack);

	}

}