diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e46de641ea4..868e121c8e3 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -96,6 +96,9 @@ static DEFINE_PER_CPU(struct trace_array_cpu, max_data); /* tracer_enabled is used to toggle activation of a tracer */ static int tracer_enabled = 1; +/* function tracing enabled */ +int ftrace_function_enabled; + /* * trace_nr_entries is the number of entries that is allocated * for a buffer. Note, the number of entries is always rounded @@ -134,6 +137,7 @@ static notrace void no_trace_init(struct trace_array *tr) { int cpu; + ftrace_function_enabled = 0; if(tr->ctrl) for_each_online_cpu(cpu) tracing_reset(tr->data[cpu]); @@ -1027,7 +1031,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) long disabled; int cpu; - if (unlikely(!tracer_enabled)) + if (unlikely(!ftrace_function_enabled)) return; if (skip_trace(ip)) @@ -1052,11 +1056,15 @@ static struct ftrace_ops trace_ops __read_mostly = void tracing_start_function_trace(void) { + ftrace_function_enabled = 0; register_ftrace_function(&trace_ops); + if (tracer_enabled) + ftrace_function_enabled = 1; } void tracing_stop_function_trace(void) { + ftrace_function_enabled = 0; unregister_ftrace_function(&trace_ops); } #endif @@ -1383,7 +1391,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) "server", #elif defined(CONFIG_PREEMPT_VOLUNTARY) "desktop", -#elif defined(CONFIG_PREEMPT_DESKTOP) +#elif defined(CONFIG_PREEMPT) "preempt", #else "unknown", @@ -1892,8 +1900,10 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) m->private = iter; /* stop the trace while dumping */ - if (iter->tr->ctrl) + if (iter->tr->ctrl) { tracer_enabled = 0; + ftrace_function_enabled = 0; + } if (iter->trace && iter->trace->open) iter->trace->open(iter); @@ -1926,8 +1936,14 @@ int tracing_release(struct inode *inode, struct file *file) iter->trace->close(iter); /* reenable tracing if it was previously enabled */ - if (iter->tr->ctrl) + if (iter->tr->ctrl) { tracer_enabled = 1; + /* + * It is safe to enable function tracing even if it + * isn't used + */ + ftrace_function_enabled = 1; + } mutex_unlock(&trace_types_lock); seq_release(inode, file); |