Merge tag 'pm-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/rafael/linux-pm

Pull more power management updates from Rafael Wysocki:
 "These remove a questionable heuristic from the menu cpuidle governor,
  fix a recent build regression in the intel_pstate driver, clean up ARM
  big-Little support in cpufreq and fix up hung task watchdog's
  interaction with system-wide power management transitions.

  Specifics:

   - Fix build regression in the intel_pstate driver that doesn't build
     without CONFIG_ACPI after recent changes (Dominik Brodowski).

   - One of the heuristics in the menu cpuidle governor is based on a
     function returning 0 most of the time, so drop it and clean up the
     scheduler code related to it (Daniel Lezcano).

   - Prevent the arm_big_little cpufreq driver from being used on ARM64
     which is not suitable for it and drop the arm_big_little_dt driver
     that is not used any more (Sudeep Holla).

   - Prevent the hung task watchdog from triggering during resume from
     system-wide sleep states by disabling it before freezing tasks and
     enabling it again after they have been thawed (Vitaly Kuznetsov)"

* tag 'pm-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  kernel: hung_task.c: disable on suspend
  cpufreq: remove unused arm_big_little_dt driver
  cpufreq: drop ARM_BIG_LITTLE_CPUFREQ support for ARM64
  cpufreq: intel_pstate: Fix compilation for !CONFIG_ACPI
  cpuidle: menu: Remove get_loadavg() from the performance multiplier
  sched: Factor out nr_iowait and nr_iowait_cpu

MAINTAINERS

@@ -3823,7 +3823,6 @@ W:	http://www.arm.com/products/processors/technologies/biglittleprocessing.php
 S:	Maintained
 F:	drivers/cpufreq/arm_big_little.h
 F:	drivers/cpufreq/arm_big_little.c
-F:	drivers/cpufreq/arm_big_little_dt.c
 
 CPU POWER MONITORING SUBSYSTEM
 M:	Thomas Renninger <[email protected]>

drivers/cpufreq/Kconfig.arm

@@ -28,20 +28,13 @@ config ARM_ARMADA_37XX_CPUFREQ
 # big LITTLE core layer and glue drivers
 config ARM_BIG_LITTLE_CPUFREQ
 	tristate "Generic ARM big LITTLE CPUfreq driver"
-	depends on (ARM_CPU_TOPOLOGY || ARM64) && HAVE_CLK
+	depends on ARM_CPU_TOPOLOGY && HAVE_CLK
 	# if CPU_THERMAL is on and THERMAL=m, ARM_BIT_LITTLE_CPUFREQ cannot be =y
 	depends on !CPU_THERMAL || THERMAL
 	select PM_OPP
 	help
 	  This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.
 
-config ARM_DT_BL_CPUFREQ
-	tristate "Generic probing via DT for ARM big LITTLE CPUfreq driver"
-	depends on ARM_BIG_LITTLE_CPUFREQ && OF
-	help
-	  This enables probing via DT for Generic CPUfreq driver for ARM
-	  big.LITTLE platform. This gets frequency tables from DT.
-
 config ARM_SCPI_CPUFREQ
 	tristate "SCPI based CPUfreq driver"
 	depends on ARM_SCPI_PROTOCOL && COMMON_CLK_SCPI

drivers/cpufreq/Makefile

@@ -48,9 +48,6 @@ obj-$(CONFIG_X86_SFI_CPUFREQ)		+= sfi-cpufreq.o
 ##################################################################################
 # ARM SoC drivers
 obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ)	+= arm_big_little.o
-# big LITTLE per platform glues. Keep DT_BL_CPUFREQ as the last entry in all big
-# LITTLE drivers, so that it is probed last.
-obj-$(CONFIG_ARM_DT_BL_CPUFREQ)		+= arm_big_little_dt.o
 
 obj-$(CONFIG_ARM_ARMADA_37XX_CPUFREQ)	+= armada-37xx-cpufreq.o
 obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ)	+= brcmstb-avs-cpufreq.o

drivers/cpufreq/intel_pstate.c

@@ -386,16 +386,11 @@ static int intel_pstate_get_cppc_guranteed(int cpu)
 	return cppc_perf.guaranteed_perf;
 }
 
-#else
+#else /* CONFIG_ACPI_CPPC_LIB */
 static void intel_pstate_set_itmt_prio(int cpu)
 {
 }
-
-static int intel_pstate_get_cppc_guranteed(int cpu)
-{
-	return -ENOTSUPP;
-}
-#endif
+#endif /* CONFIG_ACPI_CPPC_LIB */
 
 static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
 {
@@ -477,7 +472,7 @@ static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
 
 	acpi_processor_unregister_performance(policy->cpu);
 }
-#else
+#else /* CONFIG_ACPI */
 static inline void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
 {
 }
@@ -490,7 +485,14 @@ static inline bool intel_pstate_acpi_pm_profile_server(void)
 {
 	return false;
 }
-#endif
+#endif /* CONFIG_ACPI */
+
+#ifndef CONFIG_ACPI_CPPC_LIB
+static int intel_pstate_get_cppc_guranteed(int cpu)
+{
+	return -ENOTSUPP;
+}
+#endif /* CONFIG_ACPI_CPPC_LIB */
 
 static inline void update_turbo_state(void)
 {

drivers/cpuidle/governors/menu.c

@@ -130,11 +130,6 @@ struct menu_device {
 	int		interval_ptr;
 };
 
-static inline int get_loadavg(unsigned long load)
-{
-	return LOAD_INT(load) * 10 + LOAD_FRAC(load) / 10;
-}
-
 static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters)
 {
 	int bucket = 0;
@@ -168,18 +163,10 @@ static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters
  * to be, the higher this multiplier, and thus the higher
  * the barrier to go to an expensive C state.
  */
-static inline int performance_multiplier(unsigned long nr_iowaiters, unsigned long load)
+static inline int performance_multiplier(unsigned long nr_iowaiters)
 {
-	int mult = 1;
-
-	/* for higher loadavg, we are more reluctant */
-
-	mult += 2 * get_loadavg(load);
-
-	/* for IO wait tasks (per cpu!) we add 5x each */
-	mult += 10 * nr_iowaiters;
-
-	return mult;
+	/* for IO wait tasks (per cpu!) we add 10x each */
+	return 1 + 10 * nr_iowaiters;
 }
 
 static DEFINE_PER_CPU(struct menu_device, menu_devices);
@@ -297,7 +284,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	int idx;
 	unsigned int interactivity_req;
 	unsigned int predicted_us;
-	unsigned long nr_iowaiters, cpu_load;
+	unsigned long nr_iowaiters;
 	ktime_t delta_next;
 
 	if (data->needs_update) {
@@ -308,7 +295,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	/* determine the expected residency time, round up */
 	data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length(&delta_next));
 
-	get_iowait_load(&nr_iowaiters, &cpu_load);
+	nr_iowaiters = nr_iowait_cpu(dev->cpu);
 	data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
 
 	if (unlikely(drv->state_count <= 1 || latency_req == 0) ||
@@ -352,7 +339,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		 * Use the performance multiplier and the user-configurable
 		 * latency_req to determine the maximum exit latency.
 		 */
-		interactivity_req = predicted_us / performance_multiplier(nr_iowaiters, cpu_load);
+		interactivity_req = predicted_us / performance_multiplier(nr_iowaiters);
 		if (latency_req > interactivity_req)
 			latency_req = interactivity_req;
 	}

include/linux/sched/stat.h

@@ -20,7 +20,6 @@ extern unsigned long nr_running(void);
 extern bool single_task_running(void);
 extern unsigned long nr_iowait(void);
 extern unsigned long nr_iowait_cpu(int cpu);
-extern void get_iowait_load(unsigned long *nr_waiters, unsigned long *load);
 
 static inline int sched_info_on(void)
 {

kernel/hung_task.c

@@ -15,6 +15,7 @@
 #include <linux/lockdep.h>
 #include <linux/export.h>
 #include <linux/sysctl.h>
+#include <linux/suspend.h>
 #include <linux/utsname.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/debug.h>
@@ -242,6 +243,28 @@ void reset_hung_task_detector(void)
 }
 EXPORT_SYMBOL_GPL(reset_hung_task_detector);
 
+static bool hung_detector_suspended;
+
+static int hungtask_pm_notify(struct notifier_block *self,
+			      unsigned long action, void *hcpu)
+{
+	switch (action) {
+	case PM_SUSPEND_PREPARE:
+	case PM_HIBERNATION_PREPARE:
+	case PM_RESTORE_PREPARE:
+		hung_detector_suspended = true;
+		break;
+	case PM_POST_SUSPEND:
+	case PM_POST_HIBERNATION:
+	case PM_POST_RESTORE:
+		hung_detector_suspended = false;
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
 /*
  * kthread which checks for tasks stuck in D state
  */
@@ -261,7 +284,8 @@ static int watchdog(void *dummy)
 		interval = min_t(unsigned long, interval, timeout);
 		t = hung_timeout_jiffies(hung_last_checked, interval);
 		if (t <= 0) {
-			if (!atomic_xchg(&reset_hung_task, 0))
+			if (!atomic_xchg(&reset_hung_task, 0) &&
+			    !hung_detector_suspended)
 				check_hung_uninterruptible_tasks(timeout);
 			hung_last_checked = jiffies;
 			continue;
@@ -275,6 +299,10 @@ static int watchdog(void *dummy)
 static int __init hung_task_init(void)
 {
 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
+
+	/* Disable hung task detector on suspend */
+	pm_notifier(hungtask_pm_notify, 0);
+
 	watchdog_task = kthread_run(watchdog, NULL, "khungtaskd");
 
 	return 0;

kernel/sched/core.c

@@ -2880,6 +2880,18 @@ unsigned long long nr_context_switches(void)
 	return sum;
 }
 
+/*
+ * Consumers of these two interfaces, like for example the cpuidle menu
+ * governor, are using nonsensical data. Preferring shallow idle state selection
+ * for a CPU that has IO-wait which might not even end up running the task when
+ * it does become runnable.
+ */
+
+unsigned long nr_iowait_cpu(int cpu)
+{
+	return atomic_read(&cpu_rq(cpu)->nr_iowait);
+}
+
 /*
  * IO-wait accounting, and how its mostly bollocks (on SMP).
  *
@@ -2915,31 +2927,11 @@ unsigned long nr_iowait(void)
 	unsigned long i, sum = 0;
 
 	for_each_possible_cpu(i)
-		sum += atomic_read(&cpu_rq(i)->nr_iowait);
+		sum += nr_iowait_cpu(i);
 
 	return sum;
 }
 
-/*
- * Consumers of these two interfaces, like for example the cpuidle menu
- * governor, are using nonsensical data. Preferring shallow idle state selection
- * for a CPU that has IO-wait which might not even end up running the task when
- * it does become runnable.
- */
-
-unsigned long nr_iowait_cpu(int cpu)
-{
-	struct rq *this = cpu_rq(cpu);
-	return atomic_read(&this->nr_iowait);
-}
-
-void get_iowait_load(unsigned long *nr_waiters, unsigned long *load)
-{
-	struct rq *rq = this_rq();
-	*nr_waiters = atomic_read(&rq->nr_iowait);
-	*load = rq->load.weight;
-}
-
 #ifdef CONFIG_SMP
 
 /*