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-rw-r--r--kernel/sched_clock.c345
1 files changed, 0 insertions, 345 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
deleted file mode 100644
index 22ed55d1167..00000000000
--- a/kernel/sched_clock.c
+++ /dev/null
@@ -1,345 +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
- * - jiffies
- * - 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. This window
- * is set up using jiffies.
- *
- * 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 1 jiffies difference).
- */
-#include <linux/sched.h>
-#include <linux/percpu.h>
-#include <linux/spinlock.h>
-#include <linux/ktime.h>
-#include <linux/module.h>
-
-
-#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
-
-#define MULTI_SHIFT 15
-/* Max is double, Min is 1/2 */
-#define MAX_MULTI (2LL << MULTI_SHIFT)
-#define MIN_MULTI (1LL << (MULTI_SHIFT-1))
-
-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;
-
- unsigned long tick_jiffies;
- u64 prev_raw;
- u64 tick_raw;
- u64 tick_gtod;
- u64 clock;
- s64 multi;
-#ifdef CONFIG_NO_HZ
- int check_max;
-#endif
-};
-
-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);
-}
-
-static __read_mostly int sched_clock_running;
-
-void sched_clock_init(void)
-{
- u64 ktime_now = ktime_to_ns(ktime_get());
- unsigned long now_jiffies = jiffies;
- 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_jiffies = now_jiffies;
- scd->prev_raw = 0;
- scd->tick_raw = 0;
- scd->tick_gtod = ktime_now;
- scd->clock = ktime_now;
- scd->multi = 1 << MULTI_SHIFT;
-#ifdef CONFIG_NO_HZ
- scd->check_max = 1;
-#endif
- }
-
- sched_clock_running = 1;
-}
-
-#ifdef CONFIG_NO_HZ
-/*
- * The dynamic ticks makes the delta jiffies inaccurate. This
- * prevents us from checking the maximum time update.
- * Disable the maximum check during stopped ticks.
- */
-void sched_clock_tick_stop(int cpu)
-{
- struct sched_clock_data *scd = cpu_sdc(cpu);
-
- scd->check_max = 0;
-}
-
-void sched_clock_tick_start(int cpu)
-{
- struct sched_clock_data *scd = cpu_sdc(cpu);
-
- scd->check_max = 1;
-}
-
-static int check_max(struct sched_clock_data *scd)
-{
- return scd->check_max;
-}
-#else
-static int check_max(struct sched_clock_data *scd)
-{
- return 1;
-}
-#endif /* CONFIG_NO_HZ */
-
-/*
- * update the percpu scd from the raw @now value
- *
- * - filter out backward motion
- * - use jiffies to generate a min,max window to clip the raw values
- */
-static void __update_sched_clock(struct sched_clock_data *scd, u64 now, u64 *time)
-{
- unsigned long now_jiffies = jiffies;
- long delta_jiffies = now_jiffies - scd->tick_jiffies;
- u64 clock = scd->clock;
- u64 min_clock, max_clock;
- s64 delta = now - scd->prev_raw;
-
- WARN_ON_ONCE(!irqs_disabled());
-
- /*
- * At schedule tick the clock can be just under the gtod. We don't
- * want to push it too prematurely.
- */
- min_clock = scd->tick_gtod + (delta_jiffies * TICK_NSEC);
- if (min_clock > TICK_NSEC)
- min_clock -= TICK_NSEC / 2;
-
- if (unlikely(delta < 0)) {
- clock++;
- goto out;
- }
-
- /*
- * The clock must stay within a jiffie of the gtod.
- * But since we may be at the start of a jiffy or the end of one
- * we add another jiffy buffer.
- */
- max_clock = scd->tick_gtod + (2 + delta_jiffies) * TICK_NSEC;
-
- delta *= scd->multi;
- delta >>= MULTI_SHIFT;
-
- if (unlikely(clock + delta > max_clock) && check_max(scd)) {
- if (clock < max_clock)
- clock = max_clock;
- else
- clock++;
- } else {
- clock += delta;
- }
-
- out:
- if (unlikely(clock < min_clock))
- clock = min_clock;
-
- if (time)
- *time = clock;
- else {
- scd->prev_raw = now;
- scd->clock = 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)
-{
- struct sched_clock_data *scd = cpu_sdc(cpu);
- u64 now, clock;
-
- if (unlikely(!sched_clock_running))
- return 0ull;
-
- WARN_ON_ONCE(!irqs_disabled());
- now = sched_clock();
-
- if (cpu != raw_smp_processor_id()) {
- /*
- * in order to update a remote cpu's clock based on our
- * unstable raw time rebase it against:
- * tick_raw (offset between raw counters)
- * tick_gotd (tick offset between cpus)
- */
- struct sched_clock_data *my_scd = this_scd();
-
- lock_double_clock(scd, my_scd);
-
- now -= my_scd->tick_raw;
- now += scd->tick_raw;
-
- now += my_scd->tick_gtod;
- now -= scd->tick_gtod;
-
- __raw_spin_unlock(&my_scd->lock);
-
- __update_sched_clock(scd, now, &clock);
-
- __raw_spin_unlock(&scd->lock);
-
- } else {
- __raw_spin_lock(&scd->lock);
- __update_sched_clock(scd, now, NULL);
- clock = scd->clock;
- __raw_spin_unlock(&scd->lock);
- }
-
- return clock;
-}
-
-void sched_clock_tick(void)
-{
- struct sched_clock_data *scd = this_scd();
- unsigned long now_jiffies = jiffies;
- s64 mult, delta_gtod, delta_raw;
- u64 now, now_gtod;
-
- if (unlikely(!sched_clock_running))
- return;
-
- WARN_ON_ONCE(!irqs_disabled());
-
- now_gtod = ktime_to_ns(ktime_get());
- now = sched_clock();
-
- __raw_spin_lock(&scd->lock);
- __update_sched_clock(scd, now, NULL);
- /*
- * update tick_gtod after __update_sched_clock() because that will
- * already observe 1 new jiffy; adding a new tick_gtod to that would
- * increase the clock 2 jiffies.
- */
- delta_gtod = now_gtod - scd->tick_gtod;
- delta_raw = now - scd->tick_raw;
-
- if ((long)delta_raw > 0) {
- mult = delta_gtod << MULTI_SHIFT;
- do_div(mult, delta_raw);
- scd->multi = mult;
- if (scd->multi > MAX_MULTI)
- scd->multi = MAX_MULTI;
- else if (scd->multi < MIN_MULTI)
- scd->multi = MIN_MULTI;
- } else
- scd->multi = 1 << MULTI_SHIFT;
-
- scd->tick_raw = now;
- scd->tick_gtod = now_gtod;
- scd->tick_jiffies = now_jiffies;
- __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)
-{
- struct sched_clock_data *scd = this_scd();
- u64 now = sched_clock();
-
- /*
- * Override the previous timestamp and ignore all
- * sched_clock() deltas that occured while we idled,
- * and use the PM-provided delta_ns to advance the
- * rq clock:
- */
- __raw_spin_lock(&scd->lock);
- scd->prev_raw = now;
- scd->clock += delta_ns;
- scd->multi = 1 << MULTI_SHIFT;
- __raw_spin_unlock(&scd->lock);
-
- touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
-
-#endif
-
-/*
- * 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 * (NSEC_PER_SEC / HZ);
-}
-
-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);