Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 843f4f4b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-fixes-3.13-rc2' of... 

Merge tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "A regression showed up that there's a large delay when enabling all
  events.  This was prevalent when FTRACE_SELFTEST was enabled which
  enables all events several times, and caused the system bootup to
  pause for over a minute.

  This was tracked down to an addition of a synchronize_sched()
  performed when system call tracepoints are unregistered.

  The synchronize_sched() is needed between the unregistering of the
  system call tracepoint and a deletion of a tracing instance buffer.
  But placing the synchronize_sched() in the unreg of *every* system
  call tracepoint is a bit overboard.  A single synchronize_sched()
  before the deletion of the instance is sufficient"

* tag 'trace-fixes-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Only run synchronize_sched() at instance deletion time
parents c537aba0 3ccb0123

kernel/trace/trace_events.c

+3 −0
Original line number Diff line number Diff line
@@ -2314,6 +2314,9 @@ int event_trace_del_tracer(struct trace_array *tr) 
	/* Disable any running events */

	__ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);



	/* Access to events are within rcu_read_lock_sched() */

	synchronize_sched();



	down_write(&trace_event_sem);

	__trace_remove_event_dirs(tr);

	debugfs_remove_recursive(tr->event_dir);

kernel/trace/trace_syscalls.c

+0 −10
Original line number Diff line number Diff line
@@ -431,11 +431,6 @@ static void unreg_event_syscall_enter(struct ftrace_event_file *file, 
	if (!tr->sys_refcount_enter)

		unregister_trace_sys_enter(ftrace_syscall_enter, tr);

	mutex_unlock(&syscall_trace_lock);

	/*

	 * Callers expect the event to be completely disabled on

	 * return, so wait for current handlers to finish.

	 */

	synchronize_sched();

}



static int reg_event_syscall_exit(struct ftrace_event_file *file,
@@ -474,11 +469,6 @@ static void unreg_event_syscall_exit(struct ftrace_event_file *file, 
	if (!tr->sys_refcount_exit)

		unregister_trace_sys_exit(ftrace_syscall_exit, tr);

	mutex_unlock(&syscall_trace_lock);

	/*

	 * Callers expect the event to be completely disabled on

	 * return, so wait for current handlers to finish.

	 */

	synchronize_sched();

}



static int __init init_syscall_trace(struct ftrace_event_call *call)