Commit 3330dc1b authored by Francesco Valla's avatar Francesco Valla Committed by Andrew Morton
Browse files

init/main.c: log initcall level when initcall_debug is used 

When initcall_debug is specified on the command line, the start and return
point for each initcall is printed.  However, no information on the
initcall level is reported.

Add to the initcall_debug infrastructure an additional print that informs
when a new initcall level is entered.  This is particularly useful when
debugging dependency chains and/or working on boot time reduction.

Link: https://lkml.kernel.org/r/20250316205014.2830071-2-francesco@valla.it


Signed-off-by: default avatarFrancesco Valla <francesco@valla.it>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Bird <tim.bird@sony.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3ca55ca2

init/main.c

+16 −2
Original line number Diff line number Diff line
@@ -1214,6 +1214,12 @@ trace_initcall_finish_cb(void *data, initcall_t fn, int ret) 
		 fn, ret, (unsigned long long)ktime_us_delta(rettime, *calltime));

}



static __init_or_module void

trace_initcall_level_cb(void *data, const char *level)

{

	printk(KERN_DEBUG "entering initcall level: %s\n", level);

}



static ktime_t initcall_calltime;



#ifdef TRACEPOINTS_ENABLED
@@ -1225,10 +1231,12 @@ static void __init initcall_debug_enable(void) 
					    &initcall_calltime);

	ret |= register_trace_initcall_finish(trace_initcall_finish_cb,

					      &initcall_calltime);

	ret |= register_trace_initcall_level(trace_initcall_level_cb, NULL);

	WARN(ret, "Failed to register initcall tracepoints\n");

}

# define do_trace_initcall_start	trace_initcall_start

# define do_trace_initcall_finish	trace_initcall_finish

# define do_trace_initcall_level	trace_initcall_level

#else

static inline void do_trace_initcall_start(initcall_t fn)

{
@@ -1242,6 +1250,12 @@ static inline void do_trace_initcall_finish(initcall_t fn, int ret) 
		return;

	trace_initcall_finish_cb(&initcall_calltime, fn, ret);

}

static inline void do_trace_initcall_level(const char *level)

{

	if (!initcall_debug)

		return;

	trace_initcall_level_cb(NULL, level);

}

#endif /* !TRACEPOINTS_ENABLED */



int __init_or_module do_one_initcall(initcall_t fn)
@@ -1314,7 +1328,7 @@ static void __init do_initcall_level(int level, char *command_line) 
		   level, level,

		   NULL, ignore_unknown_bootoption);



	trace_initcall_level(initcall_level_names[level]);

	do_trace_initcall_level(initcall_level_names[level]);

	for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)

		do_one_initcall(initcall_from_entry(fn));

}
@@ -1358,7 +1372,7 @@ static void __init do_pre_smp_initcalls(void) 
{

	initcall_entry_t *fn;



	trace_initcall_level("early");

	do_trace_initcall_level("early");

	for (fn = __initcall_start; fn < __initcall0_start; fn++)

		do_one_initcall(initcall_from_entry(fn));

}