The following commit has been merged into the timers/core branch of tip:
Commit-ID: 14f1e3b3dfc7fc8b61fcb79f956f05625af6f049
Gitweb: https://git.kernel.org/tip/14f1e3b3dfc7fc8b61fcb79f956f05625af6f049
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Wed, 09 Oct 2024 10:28:54 +02:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 25 Oct 2024 19:49:12 +02:00
timekeeping: Read NTP tick length only once
No point in reading it a second time when the comparison fails.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: John Stultz <jstultz@xxxxxxxxxx>
Link: https://lore.kernel.org/all/20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-1-554456a44a15@xxxxxxxxxxxxx
---
kernel/time/timekeeping.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 1427c58..2bc3542 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -2161,16 +2161,17 @@ static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk,
*/
static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
{
+ u64 ntp_tl = ntp_tick_length();
u32 mult;
/*
* Determine the multiplier from the current NTP tick length.
* Avoid expensive division when the tick length doesn't change.
*/
- if (likely(tk->ntp_tick == ntp_tick_length())) {
+ if (likely(tk->ntp_tick == ntp_tl)) {
mult = tk->tkr_mono.mult - tk->ntp_err_mult;
} else {
- tk->ntp_tick = ntp_tick_length();
+ tk->ntp_tick = ntp_tl;
mult = div64_u64((tk->ntp_tick >> tk->ntp_error_shift) -
tk->xtime_remainder, tk->cycle_interval);
}
|