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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 19:08:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 19:08:07 +0300
commit6ef746769ef5cfef84cdfdf61ecbab5a6aa4651a (patch)
tree12baa185ef3b52c4fce8f8fc64a74c4773ca78de /kernel
parent85b5d4bcab8b46664f8e1993bd5919cb0f24a3ca (diff)
parentc4ac6889930d027ffa5cf77e0c202e7e97a4be06 (diff)
downloadlinux-6ef746769ef5cfef84cdfdf61ecbab5a6aa4651a.tar.xz
Merge tag 'pm-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/hung_task.c30
-rw-r--r--kernel/sched/core.c34
2 files changed, 42 insertions, 22 deletions
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index b9132d1269ef..cb8e3e8ac7b9 100644
--- a/kernel/hung_task.c
+++ b/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;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fd2fce8a001b..f12225f26b70 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2881,6 +2881,18 @@ unsigned long long nr_context_switches(void)
}
/*
+ * 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).
*
* The idea behind IO-wait account is to account the idle time that we could
@@ -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
/*