[RFC v5 4/6] Remove duplicate code from ktime_get_raw_and_real code

Christopher S. Hall
2016-01-04T12:45:21Z

The code in ktime_get_snapshot() is a superset of the code in
ktime_get_raw_and_real() code. Changes the latter to call the former. A
side effect of this is that ktime_get_raw_and_real() returns two clock
times corresponding to the *exact* same clock tick. Previously, this
code read the underlying counter twice.

Signed-off-by: Christopher S. Hall <christopher.s.hall@intel.com>
---
kernel/time/timekeeping.c | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5a7f784..a0f096c 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -910,26 +910,14 @@ EXPORT_SYMBOL_GPL(ktime_get_snapshot);
*/
void ktime_get_raw_and_real_ts64(struct timespec64 *ts_raw, struct timespec64 *ts_real)
{
- struct timekeeper *tk = &tk_core.timekeeper;
- unsigned long seq;
- s64 nsecs_raw, nsecs_real;
+ struct system_time_snapshot snap;

WARN_ON_ONCE(timekeeping_suspended);

- do {
- seq = read_seqcount_begin(&tk_core.seq);
-
- *ts_raw = tk->raw_time;
- ts_real->tv_sec = tk->xtime_sec;
- ts_real->tv_nsec = 0;
-
- nsecs_raw = timekeeping_get_ns(&tk->tkr_raw);
- nsecs_real = timekeeping_get_ns(&tk->tkr_mono);
-
- } while (read_seqcount_retry(&tk_core.seq, seq));
+ ktime_get_snapshot(&snap);

- timespec64_add_ns(ts_raw, nsecs_raw);
- timespec64_add_ns(ts_real, nsecs_real);
+ *ts_raw = ktime_to_timespec64(snap.raw);
+ *ts_real = ktime_to_timespec64(snap.real);
}
EXPORT_SYMBOL(ktime_get_raw_and_real_ts64);

--
2.1.4