• Frederic Weisbecker's avatar
    tracing/function-graph-tracer: handle ftrace_printk entries · 1fd8f2a3
    Frederic Weisbecker authored
    
    
    Handle the TRACE_PRINT entries from the function grapg tracer
    and output them as a C comment just below the function that called
    it, as if it was a comment inside this function.
    
    Example with an ftrace_printk inside might_sleep() function:
    
    void __might_sleep(char *file, int line)
    {
    	static unsigned long prev_jiffy;	/* ratelimiting */
    
    	ftrace_printk("Hi I'm a comment in might_sleep() :-)");
    
    A chunk of a resulting trace:
    
     0)               |        _reiserfs_free_block() {
     0)               |          reiserfs_read_bitmap_block() {
     0)               |            __bread() {
     0)               |              __getblk() {
     0)               |                __find_get_block() {
     0)   0.698 us    |                  mark_page_accessed();
     0)   2.267 us    |                }
     0)               |                __might_sleep() {
     0)               |                  /* Hi I'm a comment in might_sleep() :-) */
     0)   1.321 us    |                }
     0)   5.872 us    |              }
     0)   7.313 us    |            }
     0)   8.718 us    |          }
    
    And this patch brings two minor fixes:
    
    - The newline after a switch-out task has disappeared
    - The "|" sign just before the cpu number on task-switch has been deleted.
    
     0)   0.616 us    |                pick_next_task_rt();
     0)   1.457 us    |                _spin_trylock();
     0)   0.653 us    |                _spin_unlock();
     0)   0.728 us    |                _spin_trylock();
     0)   0.631 us    |                _spin_unlock();
     0)   0.729 us    |                native_load_sp0();
     0)   0.593 us    |                native_load_tls();
     ------------------------------------------
     0)    cat-2834    =>   migrati-3
     ------------------------------------------
    
     0)               |    finish_task_switch() {
     0)   0.841 us    |      _spin_unlock_irq();
     0)   0.616 us    |      post_schedule_rt();
     0)   3.882 us    |    }
    Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
    Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    1fd8f2a3