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tracing: Move the tracing selftest code into its own function

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Move the tracing startup selftest code into its own function and
when not enabled, always have that function succeed.

This makes the register_tracer() function much more readable.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Red Hat) 2013-03-07 11:10:56 -05:00 committed by Steven Rostedt
parent f5eb558826
commit f4e781c0a8
1 changed files with 69 additions and 55 deletions
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124
kernel/trace/trace.c
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@ -818,6 +818,72 @@ static void default_wait_pipe(struct trace_iterator *iter)
ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);
}
#ifdef CONFIG_FTRACE_STARTUP_TEST
static int run_tracer_selftest(struct tracer *type)
{
struct trace_array *tr = &global_trace;
struct tracer *saved_tracer = tr->current_trace;
int ret;
if (!type->selftest || tracing_selftest_disabled)
return 0;
/*
* Run a selftest on this tracer.
* Here we reset the trace buffer, and set the current
* tracer to be this tracer. The tracer can then run some
* internal tracing to verify that everything is in order.
* If we fail, we do not register this tracer.
*/
tracing_reset_online_cpus(&tr->trace_buffer);
tr->current_trace = type;
#ifdef CONFIG_TRACER_MAX_TRACE
if (type->use_max_tr) {
/* If we expanded the buffers, make sure the max is expanded too */
if (ring_buffer_expanded)
ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
RING_BUFFER_ALL_CPUS);
tr->allocated_snapshot = true;
}
#endif
/* the test is responsible for initializing and enabling */
pr_info("Testing tracer %s: ", type->name);
ret = type->selftest(type, tr);
/* the test is responsible for resetting too */
tr->current_trace = saved_tracer;
if (ret) {
printk(KERN_CONT "FAILED!\n");
/* Add the warning after printing 'FAILED' */
WARN_ON(1);
return -1;
}
/* Only reset on passing, to avoid touching corrupted buffers */
tracing_reset_online_cpus(&tr->trace_buffer);
#ifdef CONFIG_TRACER_MAX_TRACE
if (type->use_max_tr) {
tr->allocated_snapshot = false;
/* Shrink the max buffer again */
if (ring_buffer_expanded)
ring_buffer_resize(tr->max_buffer.buffer, 1,
RING_BUFFER_ALL_CPUS);
}
#endif
printk(KERN_CONT "PASSED\n");
return 0;
}
#else
static inline int run_tracer_selftest(struct tracer *type)
{
return 0;
}
#endif /* CONFIG_FTRACE_STARTUP_TEST */
/**
* register_tracer - register a tracer with the ftrace system.
* @type - the plugin for the tracer
@ -863,61 +929,9 @@ int register_tracer(struct tracer *type)
if (!type->wait_pipe)
type->wait_pipe = default_wait_pipe;
#ifdef CONFIG_FTRACE_STARTUP_TEST
if (type->selftest && !tracing_selftest_disabled) {
struct trace_array *tr = &global_trace;
struct tracer *saved_tracer = tr->current_trace;
/*
* Run a selftest on this tracer.
* Here we reset the trace buffer, and set the current
* tracer to be this tracer. The tracer can then run some
* internal tracing to verify that everything is in order.
* If we fail, we do not register this tracer.
*/
tracing_reset_online_cpus(&tr->trace_buffer);
tr->current_trace = type;
#ifdef CONFIG_TRACER_MAX_TRACE
if (type->use_max_tr) {
/* If we expanded the buffers, make sure the max is expanded too */
if (ring_buffer_expanded)
ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
RING_BUFFER_ALL_CPUS);
tr->allocated_snapshot = true;
}
#endif
/* the test is responsible for initializing and enabling */
pr_info("Testing tracer %s: ", type->name);
ret = type->selftest(type, tr);
/* the test is responsible for resetting too */
tr->current_trace = saved_tracer;
if (ret) {
printk(KERN_CONT "FAILED!\n");
/* Add the warning after printing 'FAILED' */
WARN_ON(1);
goto out;
}
/* Only reset on passing, to avoid touching corrupted buffers */
tracing_reset_online_cpus(&tr->trace_buffer);
#ifdef CONFIG_TRACER_MAX_TRACE
if (type->use_max_tr) {
tr->allocated_snapshot = false;
/* Shrink the max buffer again */
if (ring_buffer_expanded)
ring_buffer_resize(tr->max_buffer.buffer, 1,
RING_BUFFER_ALL_CPUS);
}
#endif
printk(KERN_CONT "PASSED\n");
}
#endif
ret = run_tracer_selftest(type);
if (ret < 0)
goto out;
type->next = trace_types;
trace_types = type;