| Message ID | 20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-25-554456a44a15@linutronix.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | timekeeping: Rework to prepare support of indenpendent PTP clocks | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
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> > > timekeeping_update_staged() is the only call site of timekeeping_update(). > > Merge those functions. No functional change. > > Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> > --- > kernel/time/timekeeping.c | 31 ++++++++++++++----------------- > 1 file changed, 14 insertions(+), 17 deletions(-) > > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > index 67d7be2e02fb..d07eb1946ff1 100644 > --- a/kernel/time/timekeeping.c > +++ b/kernel/time/timekeeping.c > @@ -529,7 +529,7 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); > * timekeeping_inject_sleeptime64() > * __timekeeping_inject_sleeptime(tk, delta); > * timestamp(); > - * timekeeping_update(tkd, tk, TK_CLEAR_NTP...); > + * timekeeping_update_staged(tkd, TK_CLEAR_NTP...); > * > * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be > * partially updated. Since the tk->offs_boot update is a rare event, this > @@ -775,10 +775,21 @@ static void timekeeping_restore_shadow(struct tk_data *tkd) > memcpy(&tkd->shadow_timekeeper, &tkd->timekeeper, sizeof(tkd->timekeeper)); > } > > -static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsigned int action) > +static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action) I still think timekeeping_update_from_shadow would be a better name. > { > + struct timekeeper *tk = &tk_core.shadow_timekeeper; > + Same naming nit, as its easy to mix up what tk is modifying. Other than those, Acked-by: John Stultz <jstultz@google.com> Thanks so much for these really nice cleanups! They are a great improvement to the code! And again, my apologies for jumping off to other things midway through reviewing these and not getting back to them until now. thanks -john
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 67d7be2e02fb..d07eb1946ff1 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -529,7 +529,7 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); * timekeeping_inject_sleeptime64() * __timekeeping_inject_sleeptime(tk, delta); * timestamp(); - * timekeeping_update(tkd, tk, TK_CLEAR_NTP...); + * timekeeping_update_staged(tkd, TK_CLEAR_NTP...); * * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be * partially updated. Since the tk->offs_boot update is a rare event, this @@ -775,10 +775,21 @@ static void timekeeping_restore_shadow(struct tk_data *tkd) memcpy(&tkd->shadow_timekeeper, &tkd->timekeeper, sizeof(tkd->timekeeper)); } -static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsigned int action) +static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action) { + struct timekeeper *tk = &tk_core.shadow_timekeeper; + lockdep_assert_held(&tkd->lock); + /* + * Block out readers before running the updates below because that + * updates VDSO and other time related infrastructure. Not blocking + * the readers might let a reader see time going backwards when + * reading from the VDSO after the VDSO update and then reading in + * the kernel from the timekeeper before that got updated. + */ + write_seqcount_begin(&tkd->seq); + if (action & TK_CLEAR_NTP) { tk->ntp_error = 0; ntp_clear(); @@ -796,20 +807,6 @@ static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsig if (action & TK_CLOCK_WAS_SET) tk->clock_was_set_seq++; -} - -static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action) -{ - /* - * Block out readers before invoking timekeeping_update() because - * that updates VDSO and other time related infrastructure. Not - * blocking the readers might let a reader see time going backwards - * when reading from the VDSO after the VDSO update and then - * reading in the kernel from the timekeeper before that got updated. - */ - write_seqcount_begin(&tkd->seq); - - timekeeping_update(tkd, &tkd->shadow_timekeeper, action); /* * Update the real timekeeper. @@ -819,7 +816,7 @@ static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action) * the cacheline optimized data layout of the timekeeper and requires * another indirection. */ - memcpy(&tkd->timekeeper, &tkd->shadow_timekeeper, sizeof(tkd->shadow_timekeeper)); + memcpy(&tkd->timekeeper, tk, sizeof(*tk)); write_seqcount_end(&tkd->seq); }