From 3330dc1b2074629c74008ea0ee0b4fb279ce8992 Mon Sep 17 00:00:00 2001 From: Francesco Valla Date: Sun, 16 Mar 2025 21:50:15 +0100 Subject: [PATCH] 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: Francesco Valla Cc: Steven Rostedt Cc: Tim Bird Signed-off-by: Andrew Morton --- init/main.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/init/main.c b/init/main.c index 7f0a2a3dbd29..6b14e6116a1f 100644 --- a/init/main.c +++ b/init/main.c @@ -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)); } -- 2.25.1