Messages in this thread | | | Date | Mon, 5 Jun 2023 23:43:18 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH v6 07/21] timers: Introduce add_timer() variants which modify timer flags |
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Le Wed, May 10, 2023 at 09:28:03AM +0200, Anna-Maria Behnsen a écrit : > Timer might be used as pinned timer (using add_timer_on()) and later on as > non pinned timers using add_timer(). When the NOHZ timer pull at expiry > model is in place, TIMER_PINNED flag is required to be used whenever a > timer needs to expire on a dedicated CPU. Flag must no be set, if > expiration on a dedicated CPU is not required. > > add_timer_on()'s behavior will be changed during the preparation patches > for the NOHZ timer pull at expiry model to unconditionally set TIMER_PINNED > flag. To be able to reset/set the flag when queueing a timer, two variants > of add_timer() are introduced. > > This is a preparatory patch and has no functional change. > > Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> > --- > New in v6 > --- > include/linux/timer.h | 2 ++ > kernel/time/timer.c | 34 ++++++++++++++++++++++++++++++++++ > 2 files changed, 36 insertions(+) > > diff --git a/include/linux/timer.h b/include/linux/timer.h > index 9162f275819a..6f96661480dd 100644 > --- a/include/linux/timer.h > +++ b/include/linux/timer.h > @@ -180,6 +180,8 @@ extern int timer_reduce(struct timer_list *timer, unsigned long expires); > #define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1) > > extern void add_timer(struct timer_list *timer); > +extern void add_timer_local(struct timer_list *timer); > +extern void add_timer_global(struct timer_list *timer); > > extern int try_to_del_timer_sync(struct timer_list *timer); > extern int timer_delete_sync(struct timer_list *timer); > diff --git a/kernel/time/timer.c b/kernel/time/timer.c > index 1522fb81887e..ab9a8bb11a8a 100644 > --- a/kernel/time/timer.c > +++ b/kernel/time/timer.c > @@ -1242,6 +1242,40 @@ void add_timer(struct timer_list *timer) > } > EXPORT_SYMBOL(add_timer); > > +/** > + * add_timer_local - Start a timer on the local CPU > + * @timer: The timer to be started > + * > + * Same as add_timer() except that the timer flag TIMER_PINNED is set. > + * > + * See add_timer() for further details. > + */ > +void add_timer_local(struct timer_list *timer) > +{ > + if (WARN_ON_ONCE(timer_pending(timer))) > + return; > + timer->flags |= TIMER_PINNED; > + __mod_timer(timer, timer->expires, MOD_TIMER_NOTPENDING); > +} > +EXPORT_SYMBOL(add_timer_local);
This one doesn't seem to be used at the end of the patchset.
Thanks.
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