diff options
Diffstat (limited to 'kernel/sched/clock.c')
| -rw-r--r-- | kernel/sched/clock.c | 29 |
1 files changed, 8 insertions, 21 deletions
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index 7713b2b53f61..ad64efe41722 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -83,8 +83,15 @@ void sched_clock_init(void) } #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK +/* + * We must start with !__sched_clock_stable because the unstable -> stable + * transition is accurate, while the stable -> unstable transition is not. + * + * Similarly we start with __sched_clock_stable_early, thereby assuming we + * will become stable, such that there's only a single 1 -> 0 transition. + */ static DEFINE_STATIC_KEY_FALSE(__sched_clock_stable); -static int __sched_clock_stable_early; +static int __sched_clock_stable_early = 1; /* * We want: ktime_get_ns() + gtod_offset == sched_clock() + raw_offset @@ -132,24 +139,6 @@ static void __set_sched_clock_stable(void) tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE); } -void set_sched_clock_stable(void) -{ - __sched_clock_stable_early = 1; - - smp_mb(); /* matches sched_clock_init_late() */ - - /* - * This really should only be called early (before - * sched_clock_init_late()) when guestimating our sched_clock() is - * solid. - * - * After that we test stability and we can negate our guess using - * clear_sched_clock_stable, possibly from a watchdog. - */ - if (WARN_ON_ONCE(sched_clock_running == 2)) - __set_sched_clock_stable(); -} - static void __clear_sched_clock_stable(struct work_struct *work) { struct sched_clock_data *scd = this_scd(); @@ -199,8 +188,6 @@ void sched_clock_init_late(void) if (__sched_clock_stable_early) __set_sched_clock_stable(); - else - __clear_sched_clock_stable(NULL); } /* |