tracing/fastboot: add better resolution to initcall debug/tracing
Change the time resolution for initcall_debug to microseconds, from
milliseconds. This is handy to determine which initcalls you want to work
on for faster booting.
One one of my test machines, over 90% of the initcalls are less than a
millisecond and (without this patch) these are all reported as 0 msecs.
Working on the 900 us ones is more important than the 4 us ones.
With 'quiet' on the kernel command line, this adds no significant overhead
to kernel boot time.
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 5812dba..a3d4615 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -215,9 +215,9 @@
struct boot_trace {
pid_t caller;
- char func[KSYM_NAME_LEN];
+ char func[KSYM_NAME_LEN];
int result;
- unsigned long long duration;
+ unsigned long long duration; /* usecs */
ktime_t calltime;
ktime_t rettime;
};
diff --git a/init/main.c b/init/main.c
index e7939de..b2e7ff4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -721,8 +721,8 @@
if (initcall_debug) {
it.rettime = ktime_get();
delta = ktime_sub(it.rettime, it.calltime);
- it.duration = (unsigned long long) delta.tv64 >> 20;
- printk("initcall %pF returned %d after %Ld msecs\n", fn,
+ it.duration = (unsigned long long) delta.tv64 >> 10;
+ printk("initcall %pF returned %d after %Ld usecs\n", fn,
it.result, it.duration);
trace_boot(&it, fn);
}