Commit e85d471c authored by Steven Rostedt (Google)'s avatar Steven Rostedt (Google)
Browse files

tracing: Move open coded processing of tgid_map into helper function 

In preparation of moving the saved_cmdlines logic out of trace.c and into
trace_sched_switch.c, replace the open coded manipulation of tgid_map in
set_tracer_flag() into a helper function trace_alloc_tgid_map() so that it
can be easily moved into trace_sched_switch.c without changing existing
functions in trace.c.

No functional changes.

Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.338116216@goodmis.org



Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 0b18c852

kernel/trace/trace.c

+23 −15
Original line number Diff line number Diff line
@@ -5453,10 +5453,31 @@ int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) 
	return 0;

}



int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)

static int trace_alloc_tgid_map(void)

{

	int *map;



	if (tgid_map)

		return 0;



	tgid_map_max = pid_max;

	map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),

		       GFP_KERNEL);

	if (!map)

		return -ENOMEM;



	/*

	 * Pairs with smp_load_acquire() in

	 * trace_find_tgid_ptr() to ensure that if it observes

	 * the tgid_map we just allocated then it also observes

	 * the corresponding tgid_map_max value.

	 */

	smp_store_release(&tgid_map, map);

	return 0;

}



int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)

{

	if ((mask == TRACE_ITER_RECORD_TGID) ||

	    (mask == TRACE_ITER_RECORD_CMD))

		lockdep_assert_held(&event_mutex);
@@ -5479,20 +5500,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) 
		trace_event_enable_cmd_record(enabled);



	if (mask == TRACE_ITER_RECORD_TGID) {

		if (!tgid_map) {

			tgid_map_max = pid_max;

			map = kvcalloc(tgid_map_max + 1, sizeof(*tgid_map),

				       GFP_KERNEL);



			/*

			 * Pairs with smp_load_acquire() in

			 * trace_find_tgid_ptr() to ensure that if it observes

			 * the tgid_map we just allocated then it also observes

			 * the corresponding tgid_map_max value.

			 */

			smp_store_release(&tgid_map, map);

		}

		if (!tgid_map) {

		if (trace_alloc_tgid_map() < 0) {

			tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;

			return -ENOMEM;

		}