Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (fe282c60) · Commits · 戴 / test

arch/x86/kernel/tsc.c

+11 −11

Original line number	Original line	Diff line number	Diff line
	@@ -1067,6 +1067,7 @@ static struct clocksource clocksource_tsc_early = {
	.resume = tsc_resume,		.resume = tsc_resume,
	.mark_unstable = tsc_cs_mark_unstable,		.mark_unstable = tsc_cs_mark_unstable,
	.tick_stable = tsc_cs_tick_stable,		.tick_stable = tsc_cs_tick_stable,
			.list = LIST_HEAD_INIT(clocksource_tsc_early.list),
	};		};

	/*		/*
	@@ -1086,6 +1087,7 @@ static struct clocksource clocksource_tsc = {
	.resume = tsc_resume,		.resume = tsc_resume,
	.mark_unstable = tsc_cs_mark_unstable,		.mark_unstable = tsc_cs_mark_unstable,
	.tick_stable = tsc_cs_tick_stable,		.tick_stable = tsc_cs_tick_stable,
			.list = LIST_HEAD_INIT(clocksource_tsc.list),
	};		};

	void mark_tsc_unstable(char *reason)		void mark_tsc_unstable(char *reason)
	@@ -1098,13 +1100,9 @@ void mark_tsc_unstable(char *reason)
	clear_sched_clock_stable();		clear_sched_clock_stable();
	disable_sched_clock_irqtime();		disable_sched_clock_irqtime();
	pr_info("Marking TSC unstable due to %s\n", reason);		pr_info("Marking TSC unstable due to %s\n", reason);
	/* Change only the rating, when not registered */
	if (clocksource_tsc.mult) {		clocksource_mark_unstable(&clocksource_tsc_early);
	clocksource_mark_unstable(&clocksource_tsc);		clocksource_mark_unstable(&clocksource_tsc);
	} else {
	clocksource_tsc.flags \|= CLOCK_SOURCE_UNSTABLE;
	clocksource_tsc.rating = 0;
	}
	}		}

	EXPORT_SYMBOL_GPL(mark_tsc_unstable);		EXPORT_SYMBOL_GPL(mark_tsc_unstable);
	@@ -1244,7 +1242,7 @@ static void tsc_refine_calibration_work(struct work_struct *work)

	/* Don't bother refining TSC on unstable systems */		/* Don't bother refining TSC on unstable systems */
	if (tsc_unstable)		if (tsc_unstable)
	return;		goto unreg;

	/*		/*
	* Since the work is started early in boot, we may be		* Since the work is started early in boot, we may be
	@@ -1297,11 +1295,12 @@ static void tsc_refine_calibration_work(struct work_struct *work)

	out:		out:
	if (tsc_unstable)		if (tsc_unstable)
	return;		goto unreg;

	if (boot_cpu_has(X86_FEATURE_ART))		if (boot_cpu_has(X86_FEATURE_ART))
	art_related_clocksource = &clocksource_tsc;		art_related_clocksource = &clocksource_tsc;
	clocksource_register_khz(&clocksource_tsc, tsc_khz);		clocksource_register_khz(&clocksource_tsc, tsc_khz);
			unreg:
	clocksource_unregister(&clocksource_tsc_early);		clocksource_unregister(&clocksource_tsc_early);
	}		}

	@@ -1311,8 +1310,8 @@ static int __init init_tsc_clocksource(void)
	if (!boot_cpu_has(X86_FEATURE_TSC) \|\| tsc_disabled > 0 \|\| !tsc_khz)		if (!boot_cpu_has(X86_FEATURE_TSC) \|\| tsc_disabled > 0 \|\| !tsc_khz)
	return 0;		return 0;

	if (check_tsc_unstable())		if (tsc_unstable)
	return 0;		goto unreg;

	if (tsc_clocksource_reliable)		if (tsc_clocksource_reliable)
	clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;		clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
	@@ -1328,6 +1327,7 @@ static int __init init_tsc_clocksource(void)
	if (boot_cpu_has(X86_FEATURE_ART))		if (boot_cpu_has(X86_FEATURE_ART))
	art_related_clocksource = &clocksource_tsc;		art_related_clocksource = &clocksource_tsc;
	clocksource_register_khz(&clocksource_tsc, tsc_khz);		clocksource_register_khz(&clocksource_tsc, tsc_khz);
			unreg:
	clocksource_unregister(&clocksource_tsc_early);		clocksource_unregister(&clocksource_tsc_early);
	return 0;		return 0;
	}		}

kernel/time/clocksource.c

+44 −19

Original line number	Original line	Diff line number	Diff line
	@@ -119,6 +119,16 @@ static DEFINE_SPINLOCK(watchdog_lock);
	static int watchdog_running;		static int watchdog_running;
	static atomic_t watchdog_reset_pending;		static atomic_t watchdog_reset_pending;

			static void inline clocksource_watchdog_lock(unsigned long *flags)
			{
			spin_lock_irqsave(&watchdog_lock, *flags);
			}

			static void inline clocksource_watchdog_unlock(unsigned long *flags)
			{
			spin_unlock_irqrestore(&watchdog_lock, *flags);
			}

	static int clocksource_watchdog_kthread(void *data);		static int clocksource_watchdog_kthread(void *data);
	static void __clocksource_change_rating(struct clocksource *cs, int rating);		static void __clocksource_change_rating(struct clocksource *cs, int rating);

	@@ -142,9 +152,19 @@ static void __clocksource_unstable(struct clocksource *cs)
	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES \| CLOCK_SOURCE_WATCHDOG);		cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES \| CLOCK_SOURCE_WATCHDOG);
	cs->flags \|= CLOCK_SOURCE_UNSTABLE;		cs->flags \|= CLOCK_SOURCE_UNSTABLE;

			/*
			* If the clocksource is registered clocksource_watchdog_kthread() will
			* re-rate and re-select.
			*/
			if (list_empty(&cs->list)) {
			cs->rating = 0;
			return;
			}

	if (cs->mark_unstable)		if (cs->mark_unstable)
	cs->mark_unstable(cs);		cs->mark_unstable(cs);

			/* kick clocksource_watchdog_kthread() */
	if (finished_booting)		if (finished_booting)
	schedule_work(&watchdog_work);		schedule_work(&watchdog_work);
	}		}
	@@ -153,10 +173,8 @@ static void __clocksource_unstable(struct clocksource *cs)
	* clocksource_mark_unstable - mark clocksource unstable via watchdog		* clocksource_mark_unstable - mark clocksource unstable via watchdog
	* @cs: clocksource to be marked unstable		* @cs: clocksource to be marked unstable
	*		*
	* This function is called instead of clocksource_change_rating from		* This function is called by the x86 TSC code to mark clocksources as unstable;
	* cpu hotplug code to avoid a deadlock between the clocksource mutex		* it defers demotion and re-selection to a kthread.
	* and the cpu hotplug mutex. It defers the update of the clocksource
	* to the watchdog thread.
	*/		*/
	void clocksource_mark_unstable(struct clocksource *cs)		void clocksource_mark_unstable(struct clocksource *cs)
	{		{
	@@ -164,7 +182,7 @@ void clocksource_mark_unstable(struct clocksource *cs)

	spin_lock_irqsave(&watchdog_lock, flags);		spin_lock_irqsave(&watchdog_lock, flags);
	if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {		if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) {
	if (list_empty(&cs->wd_list))		if (!list_empty(&cs->list) && list_empty(&cs->wd_list))
	list_add(&cs->wd_list, &watchdog_list);		list_add(&cs->wd_list, &watchdog_list);
	__clocksource_unstable(cs);		__clocksource_unstable(cs);
	}		}
	@@ -319,9 +337,8 @@ static void clocksource_resume_watchdog(void)

	static void clocksource_enqueue_watchdog(struct clocksource *cs)		static void clocksource_enqueue_watchdog(struct clocksource *cs)
	{		{
	unsigned long flags;		INIT_LIST_HEAD(&cs->wd_list);

	spin_lock_irqsave(&watchdog_lock, flags);
	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {		if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
	/* cs is a clocksource to be watched. */		/* cs is a clocksource to be watched. */
	list_add(&cs->wd_list, &watchdog_list);		list_add(&cs->wd_list, &watchdog_list);
	@@ -331,7 +348,6 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs)
	if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)		if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
	cs->flags \|= CLOCK_SOURCE_VALID_FOR_HRES;		cs->flags \|= CLOCK_SOURCE_VALID_FOR_HRES;
	}		}
	spin_unlock_irqrestore(&watchdog_lock, flags);
	}		}

	static void clocksource_select_watchdog(bool fallback)		static void clocksource_select_watchdog(bool fallback)
	@@ -373,9 +389,6 @@ static void clocksource_select_watchdog(bool fallback)

	static void clocksource_dequeue_watchdog(struct clocksource *cs)		static void clocksource_dequeue_watchdog(struct clocksource *cs)
	{		{
	unsigned long flags;

	spin_lock_irqsave(&watchdog_lock, flags);
	if (cs != watchdog) {		if (cs != watchdog) {
	if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {		if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) {
	/* cs is a watched clocksource. */		/* cs is a watched clocksource. */
	@@ -384,21 +397,19 @@ static void clocksource_dequeue_watchdog(struct clocksource *cs)
	clocksource_stop_watchdog();		clocksource_stop_watchdog();
	}		}
	}		}
	spin_unlock_irqrestore(&watchdog_lock, flags);
	}		}

	static int __clocksource_watchdog_kthread(void)		static int __clocksource_watchdog_kthread(void)
	{		{
	struct clocksource cs, tmp;		struct clocksource cs, tmp;
	unsigned long flags;		unsigned long flags;
	LIST_HEAD(unstable);
	int select = 0;		int select = 0;

	spin_lock_irqsave(&watchdog_lock, flags);		spin_lock_irqsave(&watchdog_lock, flags);
	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {		list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
	if (cs->flags & CLOCK_SOURCE_UNSTABLE) {		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
	list_del_init(&cs->wd_list);		list_del_init(&cs->wd_list);
	list_add(&cs->wd_list, &unstable);		__clocksource_change_rating(cs, 0);
	select = 1;		select = 1;
	}		}
	if (cs->flags & CLOCK_SOURCE_RESELECT) {		if (cs->flags & CLOCK_SOURCE_RESELECT) {
	@@ -410,11 +421,6 @@ static int __clocksource_watchdog_kthread(void)
	clocksource_stop_watchdog();		clocksource_stop_watchdog();
	spin_unlock_irqrestore(&watchdog_lock, flags);		spin_unlock_irqrestore(&watchdog_lock, flags);

	/* Needs to be done outside of watchdog lock */
	list_for_each_entry_safe(cs, tmp, &unstable, wd_list) {
	list_del_init(&cs->wd_list);
	__clocksource_change_rating(cs, 0);
	}
	return select;		return select;
	}		}

	@@ -447,6 +453,9 @@ static inline int __clocksource_watchdog_kthread(void) { return 0; }
	static bool clocksource_is_watchdog(struct clocksource *cs) { return false; }		static bool clocksource_is_watchdog(struct clocksource *cs) { return false; }
	void clocksource_mark_unstable(struct clocksource *cs) { }		void clocksource_mark_unstable(struct clocksource *cs) { }

			static void inline clocksource_watchdog_lock(unsigned long *flags) { }
			static void inline clocksource_watchdog_unlock(unsigned long *flags) { }

	#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */		#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */

	/**		/**
	@@ -779,14 +788,19 @@ EXPORT_SYMBOL_GPL(__clocksource_update_freq_scale);
	*/		*/
	int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)		int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
	{		{
			unsigned long flags;

	/* Initialize mult/shift and max_idle_ns */		/* Initialize mult/shift and max_idle_ns */
	__clocksource_update_freq_scale(cs, scale, freq);		__clocksource_update_freq_scale(cs, scale, freq);

	/* Add clocksource to the clocksource list */		/* Add clocksource to the clocksource list */
	mutex_lock(&clocksource_mutex);		mutex_lock(&clocksource_mutex);

			clocksource_watchdog_lock(&flags);
	clocksource_enqueue(cs);		clocksource_enqueue(cs);
	clocksource_enqueue_watchdog(cs);		clocksource_enqueue_watchdog(cs);
			clocksource_watchdog_unlock(&flags);

	clocksource_select();		clocksource_select();
	clocksource_select_watchdog(false);		clocksource_select_watchdog(false);
	mutex_unlock(&clocksource_mutex);		mutex_unlock(&clocksource_mutex);
	@@ -808,8 +822,13 @@ static void __clocksource_change_rating(struct clocksource *cs, int rating)
	*/		*/
	void clocksource_change_rating(struct clocksource *cs, int rating)		void clocksource_change_rating(struct clocksource *cs, int rating)
	{		{
			unsigned long flags;

	mutex_lock(&clocksource_mutex);		mutex_lock(&clocksource_mutex);
			clocksource_watchdog_lock(&flags);
	__clocksource_change_rating(cs, rating);		__clocksource_change_rating(cs, rating);
			clocksource_watchdog_unlock(&flags);

	clocksource_select();		clocksource_select();
	clocksource_select_watchdog(false);		clocksource_select_watchdog(false);
	mutex_unlock(&clocksource_mutex);		mutex_unlock(&clocksource_mutex);
	@@ -821,6 +840,8 @@ EXPORT_SYMBOL(clocksource_change_rating);
	*/		*/
	static int clocksource_unbind(struct clocksource *cs)		static int clocksource_unbind(struct clocksource *cs)
	{		{
			unsigned long flags;

	if (clocksource_is_watchdog(cs)) {		if (clocksource_is_watchdog(cs)) {
	/* Select and try to install a replacement watchdog. */		/* Select and try to install a replacement watchdog. */
	clocksource_select_watchdog(true);		clocksource_select_watchdog(true);
	@@ -834,8 +855,12 @@ static int clocksource_unbind(struct clocksource *cs)
	if (curr_clocksource == cs)		if (curr_clocksource == cs)
	return -EBUSY;		return -EBUSY;
	}		}

			clocksource_watchdog_lock(&flags);
	clocksource_dequeue_watchdog(cs);		clocksource_dequeue_watchdog(cs);
	list_del_init(&cs->list);		list_del_init(&cs->list);
			clocksource_watchdog_unlock(&flags);

	return 0;		return 0;
	}		}

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