[PATCH 4/5] printk: Minimize time zero output

Mike Travis
2011-02-17T18:52:32Z

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Reduce the length for time zero messages by only printing "[0] ".

v2: updated to apply to x86-tip

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Jack Steiner <steiner@sgi.com>
Reviewed-by: Robin Holt <holt@sgi.com>
---
kernel/printk.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- linux.orig/kernel/printk.c
+++ linux/kernel/printk.c
@@ -818,11 +818,13 @@ asmlinkage int vprintk(const char *fmt,
unsigned long nanosec_rem;

t = cpu_clock(printk_cpu);
- nanosec_rem = do_div(t, 1000000000);
- tlen = sprintf(tbuf, "[%5lu.%06lu] ",
+ if (likely(t)) {
+ nanosec_rem = do_div(t, 1000000000);
+ tlen = sprintf(tbuf, "[%5lu.%06lu] ",
(unsigned long) t,
nanosec_rem / 1000);
-
+ } else
+ tlen = sprintf(tbuf, "[0] ");
for (tp = tbuf; tp < tbuf + tlen; tp++)
emit_log_char(*tp);
printed_len += tlen;

--