diff options
| -rw-r--r-- | arch/x86/events/core.c | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/timer.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/tsc.c | 4 | ||||
| -rw-r--r-- | drivers/tty/vt/keyboard.c | 1 | ||||
| -rw-r--r-- | include/linux/sched/clock.h | 13 | ||||
| -rw-r--r-- | kernel/sched/clock.c | 46 |
6 files changed, 44 insertions, 31 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 2aa1ad194db2..580b60f5ac83 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -2256,6 +2256,7 @@ void arch_perf_update_userpage(struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now) { struct cyc2ns_data *data; + u64 offset; userpg->cap_user_time = 0; userpg->cap_user_time_zero = 0; @@ -2263,11 +2264,13 @@ void arch_perf_update_userpage(struct perf_event *event, !!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED); userpg->pmc_width = x86_pmu.cntval_bits; - if (!sched_clock_stable()) + if (!using_native_sched_clock() || !sched_clock_stable()) return; data = cyc2ns_read_begin(); + offset = data->cyc2ns_offset + __sched_clock_offset; + /* * Internal timekeeping for enabled/running/stopped times * is always in the local_clock domain. @@ -2275,7 +2278,7 @@ void arch_perf_update_userpage(struct perf_event *event, userpg->cap_user_time = 1; userpg->time_mult = data->cyc2ns_mul; userpg->time_shift = data->cyc2ns_shift; - userpg->time_offset = data->cyc2ns_offset - now; + userpg->time_offset = offset - now; /* * cap_user_time_zero doesn't make sense when we're using a different @@ -2283,7 +2286,7 @@ void arch_perf_update_userpage(struct perf_event *event, */ if (!event->attr.use_clockid) { userpg->cap_user_time_zero = 1; - userpg->time_zero = data->cyc2ns_offset; + userpg->time_zero = offset; } cyc2ns_read_end(data); diff --git a/arch/x86/include/asm/timer.h b/arch/x86/include/asm/timer.h index a04eabd43d06..27e9f9d769b8 100644 --- a/arch/x86/include/asm/timer.h +++ b/arch/x86/include/asm/timer.h @@ -12,6 +12,8 @@ extern int recalibrate_cpu_khz(void); extern int no_timer_check; +extern bool using_native_sched_clock(void); + /* * We use the full linear equation: f(x) = a + b*x, in order to allow * a continuous function in the face of dynamic freq changes. diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index c73a7f9e881a..714dfba6a1e7 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -328,7 +328,7 @@ unsigned long long sched_clock(void) return paravirt_sched_clock(); } -static inline bool using_native_sched_clock(void) +bool using_native_sched_clock(void) { return pv_time_ops.sched_clock == native_sched_clock; } @@ -336,7 +336,7 @@ static inline bool using_native_sched_clock(void) unsigned long long sched_clock(void) __attribute__((alias("native_sched_clock"))); -static inline bool using_native_sched_clock(void) { return true; } +bool using_native_sched_clock(void) { return true; } #endif int check_tsc_unstable(void) diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c index c5f0fc906136..8af8d9542663 100644 --- a/drivers/tty/vt/keyboard.c +++ b/drivers/tty/vt/keyboard.c @@ -28,7 +28,6 @@ #include <linux/module.h> #include <linux/sched/signal.h> #include <linux/sched/debug.h> -#include <linux/sched/debug.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/mm.h> diff --git a/include/linux/sched/clock.h b/include/linux/sched/clock.h index 4a68c6791207..34fe92ce1ebd 100644 --- a/include/linux/sched/clock.h +++ b/include/linux/sched/clock.h @@ -54,15 +54,16 @@ static inline u64 local_clock(void) } #else extern void sched_clock_init_late(void); -/* - * Architectures can set this to 1 if they have specified - * CONFIG_HAVE_UNSTABLE_SCHED_CLOCK in their arch Kconfig, - * but then during bootup it turns out that sched_clock() - * is reliable after all: - */ extern int sched_clock_stable(void); extern void clear_sched_clock_stable(void); +/* + * When sched_clock_stable(), __sched_clock_offset provides the offset + * between local_clock() and sched_clock(). + */ +extern u64 __sched_clock_offset; + + extern void sched_clock_tick(void); extern void sched_clock_idle_sleep_event(void); extern void sched_clock_idle_wakeup_event(u64 delta_ns); diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index a08795e21628..00a45c45beca 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -96,10 +96,10 @@ static DEFINE_STATIC_KEY_FALSE(__sched_clock_stable); static int __sched_clock_stable_early = 1; /* - * We want: ktime_get_ns() + gtod_offset == sched_clock() + raw_offset + * We want: ktime_get_ns() + __gtod_offset == sched_clock() + __sched_clock_offset */ -static __read_mostly u64 raw_offset; -static __read_mostly u64 gtod_offset; +__read_mostly u64 __sched_clock_offset; +static __read_mostly u64 __gtod_offset; struct sched_clock_data { u64 tick_raw; @@ -131,17 +131,24 @@ static void __set_sched_clock_stable(void) /* * Attempt to make the (initial) unstable->stable transition continuous. */ - raw_offset = (scd->tick_gtod + gtod_offset) - (scd->tick_raw); + __sched_clock_offset = (scd->tick_gtod + __gtod_offset) - (scd->tick_raw); printk(KERN_INFO "sched_clock: Marking stable (%lld, %lld)->(%lld, %lld)\n", - scd->tick_gtod, gtod_offset, - scd->tick_raw, raw_offset); + scd->tick_gtod, __gtod_offset, + scd->tick_raw, __sched_clock_offset); static_branch_enable(&__sched_clock_stable); tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE); } -static void __clear_sched_clock_stable(struct work_struct *work) +static void __sched_clock_work(struct work_struct *work) +{ + static_branch_disable(&__sched_clock_stable); +} + +static DECLARE_WORK(sched_clock_work, __sched_clock_work); + +static void __clear_sched_clock_stable(void) { struct sched_clock_data *scd = this_scd(); @@ -154,17 +161,17 @@ static void __clear_sched_clock_stable(struct work_struct *work) * * Still do what we can. */ - gtod_offset = (scd->tick_raw + raw_offset) - (scd->tick_gtod); + __gtod_offset = (scd->tick_raw + __sched_clock_offset) - (scd->tick_gtod); printk(KERN_INFO "sched_clock: Marking unstable (%lld, %lld)<-(%lld, %lld)\n", - scd->tick_gtod, gtod_offset, - scd->tick_raw, raw_offset); + scd->tick_gtod, __gtod_offset, + scd->tick_raw, __sched_clock_offset); - static_branch_disable(&__sched_clock_stable); tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE); -} -static DECLARE_WORK(sched_clock_work, __clear_sched_clock_stable); + if (sched_clock_stable()) + schedule_work(&sched_clock_work); +} void clear_sched_clock_stable(void) { @@ -173,7 +180,7 @@ void clear_sched_clock_stable(void) smp_mb(); /* matches sched_clock_init_late() */ if (sched_clock_running == 2) - schedule_work(&sched_clock_work); + __clear_sched_clock_stable(); } void sched_clock_init_late(void) @@ -214,7 +221,7 @@ static inline u64 wrap_max(u64 x, u64 y) */ static u64 sched_clock_local(struct sched_clock_data *scd) { - u64 now, clock, old_clock, min_clock, max_clock; + u64 now, clock, old_clock, min_clock, max_clock, gtod; s64 delta; again: @@ -231,9 +238,10 @@ again: * scd->tick_gtod + TICK_NSEC); */ - clock = scd->tick_gtod + gtod_offset + delta; - min_clock = wrap_max(scd->tick_gtod, old_clock); - max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC); + gtod = scd->tick_gtod + __gtod_offset; + clock = gtod + delta; + min_clock = wrap_max(gtod, old_clock); + max_clock = wrap_max(old_clock, gtod + TICK_NSEC); clock = wrap_max(clock, min_clock); clock = wrap_min(clock, max_clock); @@ -317,7 +325,7 @@ u64 sched_clock_cpu(int cpu) u64 clock; if (sched_clock_stable()) - return sched_clock() + raw_offset; + return sched_clock() + __sched_clock_offset; if (unlikely(!sched_clock_running)) return 0ull; |