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Commit f54b2fe4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'tracing-fixes-for-linus' of... 

Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: limit the number of loops the ring buffer self test can make
  tracing: have function trace select kallsyms
  tracing: disable tracing while testing ring buffer
  tracing/function-graph-tracer: trace the idle tasks
parents 83ff1af9 ed4a2f37

kernel/trace/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ config FUNCTION_TRACER 
	depends on HAVE_FUNCTION_TRACER

	depends on DEBUG_KERNEL

	select FRAME_POINTER

	select KALLSYMS

	select TRACING

	select CONTEXT_SWITCH_TRACER

	help
@@ -238,6 +239,7 @@ config STACK_TRACER 
	depends on DEBUG_KERNEL

	select FUNCTION_TRACER

	select STACKTRACE

	select KALLSYMS

	help

	  This special tracer records the maximum stack footprint of the

	  kernel and displays it in debugfs/tracing/stack_trace.

kernel/trace/ftrace.c

+5 −1
Original line number Diff line number Diff line
@@ -2033,7 +2033,7 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) 
static int start_graph_tracing(void)

{

	struct ftrace_ret_stack **ret_stack_list;

	int ret;

	int ret, cpu;



	ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *

				sizeof(struct ftrace_ret_stack *),
@@ -2042,6 +2042,10 @@ static int start_graph_tracing(void) 
	if (!ret_stack_list)

		return -ENOMEM;



	/* The cpu_boot init_task->ret_stack will never be freed */

	for_each_online_cpu(cpu)

		ftrace_graph_init_task(idle_task(cpu));



	do {

		ret = alloc_retstack_tasklist(ret_stack_list);

	} while (ret == -EAGAIN);

kernel/trace/trace_selftest.c

+19 −0
Original line number Diff line number Diff line
@@ -23,10 +23,20 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) 
{

	struct ring_buffer_event *event;

	struct trace_entry *entry;

	unsigned int loops = 0;



	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {

		entry = ring_buffer_event_data(event);



		/*

		 * The ring buffer is a size of trace_buf_size, if

		 * we loop more than the size, there's something wrong

		 * with the ring buffer.

		 */

		if (loops++ > trace_buf_size) {

			printk(KERN_CONT ".. bad ring buffer ");

			goto failed;

		}

		if (!trace_valid_entry(entry)) {

			printk(KERN_CONT ".. invalid entry %d ",

				entry->type);
@@ -57,11 +67,20 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) 


	cnt = ring_buffer_entries(tr->buffer);



	/*

	 * The trace_test_buffer_cpu runs a while loop to consume all data.

	 * If the calling tracer is broken, and is constantly filling

	 * the buffer, this will run forever, and hard lock the box.

	 * We disable the ring buffer while we do this test to prevent

	 * a hard lock up.

	 */

	tracing_off();

	for_each_possible_cpu(cpu) {

		ret = trace_test_buffer_cpu(tr, cpu);

		if (ret)

			break;

	}

	tracing_on();

	__raw_spin_unlock(&ftrace_max_lock);

	local_irq_restore(flags);