Subject: [patch] enhance initcall_debug, measure latency
From: Ingo Molnar <[EMAIL PROTECTED]>

enhance the initcall_debug boot option:

 - measure the time the initcall took to execute and report
   it in units of milliseconds.

 - show the return code of initcalls (useful to see failures and
   to make sure that an initcall hung)

Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
---
 init/main.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Index: linux/init/main.c
===================================================================
--- linux.orig/init/main.c
+++ linux/init/main.c
@@ -685,6 +685,7 @@ static void __init do_initcalls(void)
        int count = preempt_count();
 
        for (call = __initcall_start; call < __initcall_end; call++) {
+               ktime_t t0, t1, delta;
                char *msg = NULL;
                char msgbuf[40];
                int result;
@@ -694,10 +695,26 @@ static void __init do_initcalls(void)
                        print_fn_descriptor_symbol(": %s()",
                                        (unsigned long) *call);
                        printk("\n");
+                       t0 = ktime_get();
                }
 
                result = (*call)();
 
+               if (initcall_debug) {
+                       t1 = ktime_get();
+                       delta = ktime_sub(t1, t0);
+
+                       printk("initcall 0x%p", *call);
+                       print_fn_descriptor_symbol(": %s()",
+                                       (unsigned long) *call);
+                       printk(" returned %d.\n", result);
+
+                       printk("initcall 0x%p ran for %Ld msecs: ",
+                               *call, delta.tv64 >> 20);
+                       print_fn_descriptor_symbol("%s()\n",
+                               (unsigned long) *call);
+               }
+
                if (result && result != -ENODEV && initcall_debug) {
                        sprintf(msgbuf, "error code %d", result);
                        msg = msgbuf;
-
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