enhance initcall_debug, measure latency
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)
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/init/main.c b/init/main.c
index 949c27b..c1537e0 100644
--- a/init/main.c
+++ b/init/main.c
@@ -648,6 +648,7 @@
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;
@@ -657,10 +658,26 @@
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, (unsigned long long)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;