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authorLinus Torvalds <torvalds@linux-foundation.org>2013-08-02 12:21:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-08-02 12:21:32 -0700
commit1fe0135b9e135ecef4eb2144027a74c3de6bf874 (patch)
tree995bd5805ac6228a85d58eba69d6eeb0a54a5ead
parentMerge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux (diff)
parentfreezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes (diff)
downloadlinux-dev-1fe0135b9e135ecef4eb2144027a74c3de6bf874.tar.xz
linux-dev-1fe0135b9e135ecef4eb2144027a74c3de6bf874.zip
Merge tag 'pm+acpi-3.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki: - Revert two cpuidle commits added during the 3.8 development cycle that turn out to have introduced a significant performance regression as requested by Jeremy Eder. - The recent patches that made the freezer less heavy-weight introduced a regression causing user-space-driven hibernation using the ioctl() interface to block indefinitely when the hibernate process executes try_to_freeze(). Fix from Colin Cross addresses this by adding a process flag to mark the hibernate/suspend process to inform the freezer that that process should be ignored. - One of the recent cpufreq reverts uncovered a problem in the core causing the cpufreq driver module refcount to become negative after a system suspend-resume cycle. Fix from Rafael J Wysocki. - The evaluation of the ACPI battery _BIX method has never worked correctly, because the commit that added support for it forgot to take the "Revision" field in the return package into account. As a result, the reading of battery info doesn't work at all on some systems, which is addressed by a fix from Lan Tianyu. * tag 'pm+acpi-3.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: freezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes ACPI / battery: Fix parsing _BIX return value cpufreq: Fix cpufreq driver module refcount balance after suspend/resume Revert "cpuidle: Quickly notice prediction failure for repeat mode" Revert "cpuidle: Quickly notice prediction failure in general case"
-rw-r--r--drivers/acpi/battery.c2
-rw-r--r--drivers/cpufreq/cpufreq.c19
-rw-r--r--drivers/cpuidle/governors/menu.c106
-rw-r--r--include/linux/sched.h1
-rw-r--r--include/linux/tick.h6
-rw-r--r--kernel/freezer.c2
-rw-r--r--kernel/power/process.c11
-rw-r--r--kernel/time/tick-sched.c9
8 files changed, 31 insertions, 125 deletions
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 082b4dd252a8..d405fbad406a 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -117,6 +117,7 @@ struct acpi_battery {
struct acpi_device *device;
struct notifier_block pm_nb;
unsigned long update_time;
+ int revision;
int rate_now;
int capacity_now;
int voltage_now;
@@ -359,6 +360,7 @@ static struct acpi_offsets info_offsets[] = {
};
static struct acpi_offsets extended_info_offsets[] = {
+ {offsetof(struct acpi_battery, revision), 0},
{offsetof(struct acpi_battery, power_unit), 0},
{offsetof(struct acpi_battery, design_capacity), 0},
{offsetof(struct acpi_battery, full_charge_capacity), 0},
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index a4ad7339588d..f0a5e2b0eb8a 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1177,14 +1177,11 @@ static int __cpufreq_remove_dev(struct device *dev,
__func__, cpu_dev->id, cpu);
}
- if ((cpus == 1) && (cpufreq_driver->target))
- __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
-
- pr_debug("%s: removing link, cpu: %d\n", __func__, cpu);
- cpufreq_cpu_put(data);
-
/* If cpu is last user of policy, free policy */
if (cpus == 1) {
+ if (cpufreq_driver->target)
+ __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
+
lock_policy_rwsem_read(cpu);
kobj = &data->kobj;
cmp = &data->kobj_unregister;
@@ -1205,9 +1202,13 @@ static int __cpufreq_remove_dev(struct device *dev,
free_cpumask_var(data->related_cpus);
free_cpumask_var(data->cpus);
kfree(data);
- } else if (cpufreq_driver->target) {
- __cpufreq_governor(data, CPUFREQ_GOV_START);
- __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+ } else {
+ pr_debug("%s: removing link, cpu: %d\n", __func__, cpu);
+ cpufreq_cpu_put(data);
+ if (cpufreq_driver->target) {
+ __cpufreq_governor(data, CPUFREQ_GOV_START);
+ __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
+ }
}
per_cpu(cpufreq_policy_cpu, cpu) = -1;
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index fe343a06b7da..bc580b67a652 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -28,13 +28,6 @@
#define MAX_INTERESTING 50000
#define STDDEV_THRESH 400
-/* 60 * 60 > STDDEV_THRESH * INTERVALS = 400 * 8 */
-#define MAX_DEVIATION 60
-
-static DEFINE_PER_CPU(struct hrtimer, menu_hrtimer);
-static DEFINE_PER_CPU(int, hrtimer_status);
-/* menu hrtimer mode */
-enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL};
/*
* Concepts and ideas behind the menu governor
@@ -116,13 +109,6 @@ enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL};
*
*/
-/*
- * The C-state residency is so long that is is worthwhile to exit
- * from the shallow C-state and re-enter into a deeper C-state.
- */
-static unsigned int perfect_cstate_ms __read_mostly = 30;
-module_param(perfect_cstate_ms, uint, 0000);
-
struct menu_device {
int last_state_idx;
int needs_update;
@@ -205,52 +191,17 @@ static u64 div_round64(u64 dividend, u32 divisor)
return div_u64(dividend + (divisor / 2), divisor);
}
-/* Cancel the hrtimer if it is not triggered yet */
-void menu_hrtimer_cancel(void)
-{
- int cpu = smp_processor_id();
- struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu);
-
- /* The timer is still not time out*/
- if (per_cpu(hrtimer_status, cpu)) {
- hrtimer_cancel(hrtmr);
- per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP;
- }
-}
-EXPORT_SYMBOL_GPL(menu_hrtimer_cancel);
-
-/* Call back for hrtimer is triggered */
-static enum hrtimer_restart menu_hrtimer_notify(struct hrtimer *hrtimer)
-{
- int cpu = smp_processor_id();
- struct menu_device *data = &per_cpu(menu_devices, cpu);
-
- /* In general case, the expected residency is much larger than
- * deepest C-state target residency, but prediction logic still
- * predicts a small predicted residency, so the prediction
- * history is totally broken if the timer is triggered.
- * So reset the correction factor.
- */
- if (per_cpu(hrtimer_status, cpu) == MENU_HRTIMER_GENERAL)
- data->correction_factor[data->bucket] = RESOLUTION * DECAY;
-
- per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP;
-
- return HRTIMER_NORESTART;
-}
-
/*
* Try detecting repeating patterns by keeping track of the last 8
* intervals, and checking if the standard deviation of that set
* of points is below a threshold. If it is... then use the
* average of these 8 points as the estimated value.
*/
-static u32 get_typical_interval(struct menu_device *data)
+static void get_typical_interval(struct menu_device *data)
{
int i = 0, divisor = 0;
uint64_t max = 0, avg = 0, stddev = 0;
int64_t thresh = LLONG_MAX; /* Discard outliers above this value. */
- unsigned int ret = 0;
again:
@@ -291,16 +242,13 @@ again:
if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
|| stddev <= 20) {
data->predicted_us = avg;
- ret = 1;
- return ret;
+ return;
} else if ((divisor * 4) > INTERVALS * 3) {
/* Exclude the max interval */
thresh = max - 1;
goto again;
}
-
- return ret;
}
/**
@@ -315,9 +263,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
int i;
int multiplier;
struct timespec t;
- int repeat = 0, low_predicted = 0;
- int cpu = smp_processor_id();
- struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu);
if (data->needs_update) {
menu_update(drv, dev);
@@ -352,7 +297,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
RESOLUTION * DECAY);
- repeat = get_typical_interval(data);
+ get_typical_interval(data);
/*
* We want to default to C1 (hlt), not to busy polling
@@ -373,10 +318,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
if (s->disabled || su->disable)
continue;
- if (s->target_residency > data->predicted_us) {
- low_predicted = 1;
+ if (s->target_residency > data->predicted_us)
continue;
- }
if (s->exit_latency > latency_req)
continue;
if (s->exit_latency * multiplier > data->predicted_us)
@@ -386,44 +329,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
data->exit_us = s->exit_latency;
}
- /* not deepest C-state chosen for low predicted residency */
- if (low_predicted) {
- unsigned int timer_us = 0;
- unsigned int perfect_us = 0;
-
- /*
- * Set a timer to detect whether this sleep is much
- * longer than repeat mode predicted. If the timer
- * triggers, the code will evaluate whether to put
- * the CPU into a deeper C-state.
- * The timer is cancelled on CPU wakeup.
- */
- timer_us = 2 * (data->predicted_us + MAX_DEVIATION);
-
- perfect_us = perfect_cstate_ms * 1000;
-
- if (repeat && (4 * timer_us < data->expected_us)) {
- RCU_NONIDLE(hrtimer_start(hrtmr,
- ns_to_ktime(1000 * timer_us),
- HRTIMER_MODE_REL_PINNED));
- /* In repeat case, menu hrtimer is started */
- per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_REPEAT;
- } else if (perfect_us < data->expected_us) {
- /*
- * The next timer is long. This could be because
- * we did not make a useful prediction.
- * In that case, it makes sense to re-enter
- * into a deeper C-state after some time.
- */
- RCU_NONIDLE(hrtimer_start(hrtmr,
- ns_to_ktime(1000 * timer_us),
- HRTIMER_MODE_REL_PINNED));
- /* In general case, menu hrtimer is started */
- per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_GENERAL;
- }
-
- }
-
return data->last_state_idx;
}
@@ -514,9 +419,6 @@ static int menu_enable_device(struct cpuidle_driver *drv,
struct cpuidle_device *dev)
{
struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
- struct hrtimer *t = &per_cpu(menu_hrtimer, dev->cpu);
- hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- t->function = menu_hrtimer_notify;
memset(data, 0, sizeof(struct menu_device));
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 50d04b92ceda..d722490da030 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1628,6 +1628,7 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut,
#define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */
#define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */
#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
+#define PF_SUSPEND_TASK 0x80000000 /* this thread called freeze_processes and should not be frozen */
/*
* Only the _current_ task can read/write to tsk->flags, but other
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 9180f4b85e6d..62bd8b72873c 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -174,10 +174,4 @@ static inline void tick_nohz_task_switch(struct task_struct *tsk) { }
#endif
-# ifdef CONFIG_CPU_IDLE_GOV_MENU
-extern void menu_hrtimer_cancel(void);
-# else
-static inline void menu_hrtimer_cancel(void) {}
-# endif /* CONFIG_CPU_IDLE_GOV_MENU */
-
#endif
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 8b2afc1c9df0..b462fa197517 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -33,7 +33,7 @@ static DEFINE_SPINLOCK(freezer_lock);
*/
bool freezing_slow_path(struct task_struct *p)
{
- if (p->flags & PF_NOFREEZE)
+ if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK))
return false;
if (pm_nosig_freezing || cgroup_freezing(p))
diff --git a/kernel/power/process.c b/kernel/power/process.c
index fc0df8486449..06ec8869dbf1 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -109,6 +109,8 @@ static int try_to_freeze_tasks(bool user_only)
/**
* freeze_processes - Signal user space processes to enter the refrigerator.
+ * The current thread will not be frozen. The same process that calls
+ * freeze_processes must later call thaw_processes.
*
* On success, returns 0. On failure, -errno and system is fully thawed.
*/
@@ -120,6 +122,9 @@ int freeze_processes(void)
if (error)
return error;
+ /* Make sure this task doesn't get frozen */
+ current->flags |= PF_SUSPEND_TASK;
+
if (!pm_freezing)
atomic_inc(&system_freezing_cnt);
@@ -168,6 +173,7 @@ int freeze_kernel_threads(void)
void thaw_processes(void)
{
struct task_struct *g, *p;
+ struct task_struct *curr = current;
if (pm_freezing)
atomic_dec(&system_freezing_cnt);
@@ -182,10 +188,15 @@ void thaw_processes(void)
read_lock(&tasklist_lock);
do_each_thread(g, p) {
+ /* No other threads should have PF_SUSPEND_TASK set */
+ WARN_ON((p != curr) && (p->flags & PF_SUSPEND_TASK));
__thaw_task(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
+ WARN_ON(!(curr->flags & PF_SUSPEND_TASK));
+ curr->flags &= ~PF_SUSPEND_TASK;
+
usermodehelper_enable();
schedule();
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e80183f4a6c4..e77edc97e036 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -827,13 +827,10 @@ void tick_nohz_irq_exit(void)
{
struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
- if (ts->inidle) {
- /* Cancel the timer because CPU already waken up from the C-states*/
- menu_hrtimer_cancel();
+ if (ts->inidle)
__tick_nohz_idle_enter(ts);
- } else {
+ else
tick_nohz_full_stop_tick(ts);
- }
}
/**
@@ -931,8 +928,6 @@ void tick_nohz_idle_exit(void)
ts->inidle = 0;
- /* Cancel the timer because CPU already waken up from the C-states*/
- menu_hrtimer_cancel();
if (ts->idle_active || ts->tick_stopped)
now = ktime_get();