[PATCH] Add getnstimestamp function

There are several functions that might seem appropriate for a timestamp:

get_cycles()
current_kernel_time()
do_gettimeofday()
<read jiffies/jiffies_64>

Each has problems with combinations of SMP-safety, low resolution, and
monotonicity. This patch adds a new function that returns a monotonic SMP-safe
timestamp with nanosecond resolution where available.

Changes:
	Split timestamp into separate patch
	Moved to kernel/time.c
	Renamed to getnstimestamp
	Fixed unintended-pointer-arithmetic bug

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/time.h b/include/linux/time.h
index bfbe92d0767c..797ccd813bb0 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -95,6 +95,7 @@ struct itimerval;
 extern int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue);
 extern int do_getitimer(int which, struct itimerval *value);
 extern void getnstimeofday (struct timespec *tv);
+extern void getnstimestamp(struct timespec *ts);
 
 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);