Commit dda64ead authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:
 "Minor tracing fixes:

   - Fix unregistering the same event twice. A user could disable the
     same event that osnoise will disable on unregistering.

   - Inform RCU of a quiescent state in the osnoise testing thread.

   - Fix some kerneldoc comments"

* tag 'trace-v5.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix some W=1 warnings in kernel doc comments
  tracing/osnoise: Force quiescent states while tracing
  tracing/osnoise: Do not unregister events twice
parents 186d32bb 78cbc651

kernel/trace/ftrace.c

+2 −2
Original line number Diff line number Diff line
@@ -7790,7 +7790,7 @@ int ftrace_is_dead(void) 


/**

 * register_ftrace_function - register a function for profiling

 * @ops - ops structure that holds the function for profiling.

 * @ops:	ops structure that holds the function for profiling.

 *

 * Register a function to be called by all functions in the

 * kernel.
@@ -7817,7 +7817,7 @@ EXPORT_SYMBOL_GPL(register_ftrace_function); 


/**

 * unregister_ftrace_function - unregister a function for profiling.

 * @ops - ops structure that holds the function to unregister

 * @ops:	ops structure that holds the function to unregister

 *

 * Unregister a function that was added to be called by ftrace profiling.

 */

kernel/trace/trace_osnoise.c

+31 −0
Original line number Diff line number Diff line
@@ -1386,6 +1386,26 @@ static int run_osnoise(void) 
					osnoise_stop_tracing();

		}



		/*

		 * In some cases, notably when running on a nohz_full CPU with

		 * a stopped tick PREEMPT_RCU has no way to account for QSs.

		 * This will eventually cause unwarranted noise as PREEMPT_RCU

		 * will force preemption as the means of ending the current

		 * grace period. We avoid this problem by calling

		 * rcu_momentary_dyntick_idle(), which performs a zero duration

		 * EQS allowing PREEMPT_RCU to end the current grace period.

		 * This call shouldn't be wrapped inside an RCU critical

		 * section.

		 *

		 * Note that in non PREEMPT_RCU kernels QSs are handled through

		 * cond_resched()

		 */

		if (IS_ENABLED(CONFIG_PREEMPT_RCU)) {

			local_irq_disable();

			rcu_momentary_dyntick_idle();

			local_irq_enable();

		}



		/*

		 * For the non-preemptive kernel config: let threads runs, if

		 * they so wish.
@@ -2200,6 +2220,17 @@ static void osnoise_workload_stop(void) 
	if (osnoise_has_registered_instances())

		return;



	/*

	 * If callbacks were already disabled in a previous stop

	 * call, there is no need to disable then again.

	 *

	 * For instance, this happens when tracing is stopped via:

	 * echo 0 > tracing_on

	 * echo nop > current_tracer.

	 */

	if (!trace_osnoise_callback_enabled)

		return;



	trace_osnoise_callback_enabled = false;

	/*

	 * Make sure that ftrace_nmi_enter/exit() see