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-rw-r--r--kernel/sched_clock.c283
1 files changed, 0 insertions, 283 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
deleted file mode 100644
index e1d16c9a768..00000000000
--- a/kernel/sched_clock.c
+++ /dev/null
@@ -1,283 +0,0 @@
-/*
- * sched_clock for unstable cpu clocks
- *
- * Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
- *
- * Updates and enhancements:
- * Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com>
- *
- * Based on code by:
- * Ingo Molnar <mingo@redhat.com>
- * Guillaume Chazarain <guichaz@gmail.com>
- *
- * Create a semi stable clock from a mixture of other events, including:
- * - gtod
- * - sched_clock()
- * - explicit idle events
- *
- * We use gtod as base and the unstable clock deltas. The deltas are filtered,
- * making it monotonic and keeping it within an expected window.
- *
- * Furthermore, explicit sleep and wakeup hooks allow us to account for time
- * that is otherwise invisible (TSC gets stopped).
- *
- * The clock: sched_clock_cpu() is monotonic per cpu, and should be somewhat
- * consistent between cpus (never more than 2 jiffies difference).
- */
-#include <linux/spinlock.h>
-#include <linux/hardirq.h>
-#include <linux/module.h>
-#include <linux/percpu.h>
-#include <linux/ktime.h>
-#include <linux/sched.h>
-
-/*
- * Scheduler clock - returns current time in nanosec units.
- * This is default implementation.
- * Architectures and sub-architectures can override this.
- */
-unsigned long long __attribute__((weak)) sched_clock(void)
-{
- return (unsigned long long)(jiffies - INITIAL_JIFFIES)
- * (NSEC_PER_SEC / HZ);
-}
-
-static __read_mostly int sched_clock_running;
-
-#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
-__read_mostly int sched_clock_stable;
-
-struct sched_clock_data {
- /*
- * Raw spinlock - this is a special case: this might be called
- * from within instrumentation code so we dont want to do any
- * instrumentation ourselves.
- */
- raw_spinlock_t lock;
-
- u64 tick_raw;
- u64 tick_gtod;
- u64 clock;
-};
-
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
-
-static inline struct sched_clock_data *this_scd(void)
-{
- return &__get_cpu_var(sched_clock_data);
-}
-
-static inline struct sched_clock_data *cpu_sdc(int cpu)
-{
- return &per_cpu(sched_clock_data, cpu);
-}
-
-void sched_clock_init(void)
-{
- u64 ktime_now = ktime_to_ns(ktime_get());
- int cpu;
-
- for_each_possible_cpu(cpu) {
- struct sched_clock_data *scd = cpu_sdc(cpu);
-
- scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
- scd->tick_raw = 0;
- scd->tick_gtod = ktime_now;
- scd->clock = ktime_now;
- }
-
- sched_clock_running = 1;
-}
-
-/*
- * min, max except they take wrapping into account
- */
-
-static inline u64 wrap_min(u64 x, u64 y)
-{
- return (s64)(x - y) < 0 ? x : y;
-}
-
-static inline u64 wrap_max(u64 x, u64 y)
-{
- return (s64)(x - y) > 0 ? x : y;
-}
-
-/*
- * update the percpu scd from the raw @now value
- *
- * - filter out backward motion
- * - use the GTOD tick value to create a window to filter crazy TSC values
- */
-static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now)
-{
- s64 delta = now - scd->tick_raw;
- u64 clock, min_clock, max_clock;
-
- if (unlikely(delta < 0))
- delta = 0;
-
- /*
- * scd->clock = clamp(scd->tick_gtod + delta,
- * max(scd->tick_gtod, scd->clock),
- * scd->tick_gtod + TICK_NSEC);
- */
-
- clock = scd->tick_gtod + delta;
- min_clock = wrap_max(scd->tick_gtod, scd->clock);
- max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
-
- clock = wrap_max(clock, min_clock);
- clock = wrap_min(clock, max_clock);
-
- scd->clock = clock;
-
- return scd->clock;
-}
-
-static void lock_double_clock(struct sched_clock_data *data1,
- struct sched_clock_data *data2)
-{
- if (data1 < data2) {
- __raw_spin_lock(&data1->lock);
- __raw_spin_lock(&data2->lock);
- } else {
- __raw_spin_lock(&data2->lock);
- __raw_spin_lock(&data1->lock);
- }
-}
-
-u64 sched_clock_cpu(int cpu)
-{
- u64 now, clock, this_clock, remote_clock;
- struct sched_clock_data *scd;
-
- if (sched_clock_stable)
- return sched_clock();
-
- scd = cpu_sdc(cpu);
-
- /*
- * Normally this is not called in NMI context - but if it is,
- * trying to do any locking here is totally lethal.
- */
- if (unlikely(in_nmi()))
- return scd->clock;
-
- if (unlikely(!sched_clock_running))
- return 0ull;
-
- WARN_ON_ONCE(!irqs_disabled());
- now = sched_clock();
-
- if (cpu != raw_smp_processor_id()) {
- struct sched_clock_data *my_scd = this_scd();
-
- lock_double_clock(scd, my_scd);
-
- this_clock = __update_sched_clock(my_scd, now);
- remote_clock = scd->clock;
-
- /*
- * Use the opportunity that we have both locks
- * taken to couple the two clocks: we take the
- * larger time as the latest time for both
- * runqueues. (this creates monotonic movement)
- */
- if (likely((s64)(remote_clock - this_clock) < 0)) {
- clock = this_clock;
- scd->clock = clock;
- } else {
- /*
- * Should be rare, but possible:
- */
- clock = remote_clock;
- my_scd->clock = remote_clock;
- }
-
- __raw_spin_unlock(&my_scd->lock);
- } else {
- __raw_spin_lock(&scd->lock);
- clock = __update_sched_clock(scd, now);
- }
-
- __raw_spin_unlock(&scd->lock);
-
- return clock;
-}
-
-void sched_clock_tick(void)
-{
- struct sched_clock_data *scd;
- u64 now, now_gtod;
-
- if (sched_clock_stable)
- return;
-
- if (unlikely(!sched_clock_running))
- return;
-
- WARN_ON_ONCE(!irqs_disabled());
-
- scd = this_scd();
- now_gtod = ktime_to_ns(ktime_get());
- now = sched_clock();
-
- __raw_spin_lock(&scd->lock);
- scd->tick_raw = now;
- scd->tick_gtod = now_gtod;
- __update_sched_clock(scd, now);
- __raw_spin_unlock(&scd->lock);
-}
-
-/*
- * We are going deep-idle (irqs are disabled):
- */
-void sched_clock_idle_sleep_event(void)
-{
- sched_clock_cpu(smp_processor_id());
-}
-EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
-
-/*
- * We just idled delta nanoseconds (called with irqs disabled):
- */
-void sched_clock_idle_wakeup_event(u64 delta_ns)
-{
- if (timekeeping_suspended)
- return;
-
- sched_clock_tick();
- touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
-
-#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
-
-void sched_clock_init(void)
-{
- sched_clock_running = 1;
-}
-
-u64 sched_clock_cpu(int cpu)
-{
- if (unlikely(!sched_clock_running))
- return 0;
-
- return sched_clock();
-}
-
-#endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
-
-unsigned long long cpu_clock(int cpu)
-{
- unsigned long long clock;
- unsigned long flags;
-
- local_irq_save(flags);
- clock = sched_clock_cpu(cpu);
- local_irq_restore(flags);
-
- return clock;
-}
-EXPORT_SYMBOL_GPL(cpu_clock);