diff mbox series

[v2,20/25] timekeeping: Rework timekeeping_inject_sleeptime64() to use shadow_timekeeper

Message ID 20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-20-554456a44a15@linutronix.de (mailing list archive)
State Not Applicable
Headers show
Series timekeeping: Rework to prepare support of indenpendent PTP clocks | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Anna-Maria Behnsen Oct. 9, 2024, 8:29 a.m. UTC
From: Anna-Maria Behnsen <anna-maria@linutronix.de>

Updates of the timekeeper can be done by operating on the shadow timekeeper
and afterwards copying the result into the real timekeeper. This has the
advantage, that the sequence count write protected region is kept as small
as possible.

Convert timekeeping_inject_sleeptime64() to use this scheme.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
---
 kernel/time/timekeeping.c | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

Comments

John Stultz Oct. 24, 2024, 10:16 p.m. UTC | #1
On Wed, Oct 9, 2024 at 1:29 AM Anna-Maria Behnsen
<anna-maria@linutronix.de> wrote:
>
> From: Anna-Maria Behnsen <anna-maria@linutronix.de>
>
> Updates of the timekeeper can be done by operating on the shadow timekeeper
> and afterwards copying the result into the real timekeeper. This has the
> advantage, that the sequence count write protected region is kept as small
> as possible.
>
> Convert timekeeping_inject_sleeptime64() to use this scheme.
>
> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
> ---
>  kernel/time/timekeeping.c | 22 +++++++---------------
>  1 file changed, 7 insertions(+), 15 deletions(-)
>
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index bb225534fee1..c1a2726a0d41 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -1893,22 +1893,14 @@ bool timekeeping_rtc_skipsuspend(void)
>   */
>  void timekeeping_inject_sleeptime64(const struct timespec64 *delta)
>  {
> -       struct timekeeper *tk = &tk_core.timekeeper;
> -       unsigned long flags;
> -
> -       raw_spin_lock_irqsave(&tk_core.lock, flags);
> -       write_seqcount_begin(&tk_core.seq);
> -
> -       suspend_timing_needed = false;
> -
> -       timekeeping_forward_now(tk);
> -
> -       __timekeeping_inject_sleeptime(tk, delta);
> -
> -       timekeeping_update(&tk_core, tk, TK_UPDATE_ALL | TK_MIRROR);
> +       scoped_guard(raw_spinlock_irqsave, &tk_core.lock) {
> +               struct timekeeper *tk = &tk_core.shadow_timekeeper;

Same nit as the rest, otherwise
Acked-by: John Stultz <jstultz@google.com>
diff mbox series

Patch

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index bb225534fee1..c1a2726a0d41 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1893,22 +1893,14 @@  bool timekeeping_rtc_skipsuspend(void)
  */
 void timekeeping_inject_sleeptime64(const struct timespec64 *delta)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&tk_core.lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-
-	suspend_timing_needed = false;
-
-	timekeeping_forward_now(tk);
-
-	__timekeeping_inject_sleeptime(tk, delta);
-
-	timekeeping_update(&tk_core, tk, TK_UPDATE_ALL | TK_MIRROR);
+	scoped_guard(raw_spinlock_irqsave, &tk_core.lock) {
+		struct timekeeper *tk = &tk_core.shadow_timekeeper;
 
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&tk_core.lock, flags);
+		suspend_timing_needed = false;
+		timekeeping_forward_now(tk);
+		__timekeeping_inject_sleeptime(tk, delta);
+		timekeeping_update_staged(&tk_core, TK_UPDATE_ALL);
+	}
 
 	/* Signal hrtimers about time change */
 	clock_was_set(CLOCK_SET_WALL | CLOCK_SET_BOOT);