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

[Mike Travis]

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

v2: updated to apply to x86-tip

Signed-off-by: Mike Travis <travis@xxxxxxx>
Reviewed-by: Jack Steiner <steiner@xxxxxxx>
Reviewed-by: Robin Holt <holt@xxxxxxx>
---
 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;

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/