linux-embedded.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tim Bird <tim.bird@am.sony.com>
To: linux-embedded <linux-embedded@vger.kernel.org>
Cc: linux kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH]  Add better resolution to initcall_debug timings
Date: Fri, 12 Sep 2008 12:51:45 -0700	[thread overview]
Message-ID: <48CAC851.4020408@am.sony.com> (raw)

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>
---
 init/main.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/init/main.c b/init/main.c
index bdc8be0..f441cad 100644
--- a/init/main.c
+++ b/init/main.c
@@ -719,8 +719,8 @@ int do_one_initcall(initcall_t fn)
 		delta = ktime_sub(t1, t0);

 		print_fn_descriptor_symbol("initcall %s", fn);
-		printk(" returned %d after %Ld msecs\n", result,
-			(unsigned long long) delta.tv64 >> 20);
+		printk(" returned %d after %Ld usecs\n", result,
+			(unsigned long long) delta.tv64 >> 10);
 	}

 	msgbuf[0] = 0;
-- 
1.5.6

                 reply	other threads:[~2008-09-12 19:51 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=48CAC851.4020408@am.sony.com \
    --to=tim.bird@am.sony.com \
    --cc=linux-embedded@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).