Merge branch 'sched-fixes-for-linus' of... (cc556c5c) · Commits · e / devices / android_kernel_teracube_2e

kernel/sched_clock.c

+34 −50

Original line number	Diff line number	Diff line
		@@ -12,19 +12,17 @@
		*
		* 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.
		* 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 1 jiffies difference).
		* consistent between cpus (never more than 2 jiffies difference).
		*/
		#include <linux/sched.h>
		#include <linux/percpu.h>
		@@ -54,7 +52,6 @@ struct sched_clock_data {
		*/
		raw_spinlock_t lock;

		unsigned long tick_jiffies;
		u64 tick_raw;
		u64 tick_gtod;
		u64 clock;
		@@ -75,14 +72,12 @@ static inline struct sched_clock_data *cpu_sdc(int cpu)
		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->tick_raw = 0;
		scd->tick_gtod = ktime_now;
		scd->clock = ktime_now;
		@@ -91,47 +86,52 @@ void sched_clock_init(void)
		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 jiffies to generate a min,max window to clip the raw values
		* - 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)
		{
		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->tick_raw;
		u64 clock, min_clock, max_clock;

		WARN_ON_ONCE(!irqs_disabled());
		min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC;

		if (unlikely(delta < 0)) {
		clock++;
		goto out;
		}
		if (unlikely(delta < 0))
		delta = 0;

		max_clock = min_clock + TICK_NSEC;
		/*
		* scd->clock = clamp(scd->tick_gtod + delta,
		* max(scd->tick_gtod, scd->clock),
		* scd->tick_gtod + TICK_NSEC);
		*/

		if (unlikely(clock + delta > max_clock)) {
		if (clock < max_clock)
		clock = max_clock;
		else
		clock++;
		} else {
		clock += delta;
		}
		clock = scd->tick_gtod + delta;
		min_clock = wrap_max(scd->tick_gtod, scd->clock);
		max_clock = scd->tick_gtod + TICK_NSEC;

		out:
		if (unlikely(clock < min_clock))
		clock = min_clock;
		clock = wrap_max(clock, min_clock);
		clock = wrap_min(clock, max_clock);

		scd->tick_jiffies = now_jiffies;
		scd->clock = clock;

		return clock;
		return scd->clock;
		}

		static void lock_double_clock(struct sched_clock_data *data1,
		@@ -171,7 +171,7 @@ u64 sched_clock_cpu(int cpu)
		* larger time as the latest time for both
		* runqueues. (this creates monotonic movement)
		*/
		if (likely(remote_clock < this_clock)) {
		if (likely((s64)(remote_clock - this_clock) < 0)) {
		clock = this_clock;
		scd->clock = clock;
		} else {
		@@ -207,14 +207,9 @@ void sched_clock_tick(void)
		now = sched_clock();

		__raw_spin_lock(&scd->lock);
		__update_sched_clock(scd, now);
		/*
		* 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.
		*/
		scd->tick_raw = now;
		scd->tick_gtod = now_gtod;
		__update_sched_clock(scd, now);
		__raw_spin_unlock(&scd->lock);
		}

		@@ -232,18 +227,7 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
		*/
		void sched_clock_idle_wakeup_event(u64 delta_ns)
		{
		struct sched_clock_data *scd = this_scd();

		/*
		* 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->clock += delta_ns;
		__raw_spin_unlock(&scd->lock);

		sched_clock_tick();
		touch_softlockup_watchdog();
		}
		EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);