From: Andrew Morton <akpm@osdl.org>
Date: Wed, 21 Sep 2005 16:55:30 +0000 (-0700)
Subject: [PATCH] Add printk_clock()
X-Git-Tag: v3.12-rc1~41433
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=31f6d9d628739c097964b8dbae939ea997da94a3;p=kernel%2Fkernel-generic.git

[PATCH] Add printk_clock()

ia64's sched_clock() accesses per-cpu data which isn't set up at boot time.
Hence ia64 cannot use printk timestamping, because printk() will crash in
sched_clock().

So make printk() use printk_clock(), defaulting to sched_clock(), overrideable
by the architecture via attribute(weak).

Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/printk.c b/kernel/printk.c
index a967605..4b8f0f9 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -488,6 +488,11 @@ static int __init printk_time_setup(char *str)
 
 __setup("time", printk_time_setup);
 
+__attribute__((weak)) unsigned long long printk_clock(void)
+{
+	return sched_clock();
+}
+
 /*
  * This is printk.  It can be called from any context.  We want it to work.
  * 
@@ -565,7 +570,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 					loglev_char = default_message_loglevel
 						+ '0';
 				}
-				t = sched_clock();
+				t = printk_clock();
 				nanosec_rem = do_div(t, 1000000000);
 				tlen = sprintf(tbuf,
 						"<%c>[%5lu.%06lu] ",