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authorDaniel Lezcano <daniel.lezcano@linaro.org>2014-11-20 15:07:41 +0100
committerDaniel Lezcano <daniel.lezcano@linaro.org>2014-11-20 15:07:41 +0100
commitb9ed965defe8f8ee2e57e0a9372c70b883a4ea3f (patch)
tree4c72d3a7bc6bd00229bce96b932626f5bb687434
parent5f0dea804d380d0fa57c0f69a8e961b058be998f (diff)
parent7c2684baf9042237fa3f72c9f230637911fe9b53 (diff)
Merge remote-tracking branch 'eas-next/eas-next' into sched/cpuidle/eas-nexteas-next-20141120sched/cpuidle/eas-next
Conflicts: include/linux/sched.h kernel/sched/Makefile
-rw-r--r--arch/x86/include/asm/preempt.h4
-rw-r--r--drivers/cpufreq/Kconfig21
-rw-r--r--drivers/tty/n_tty.c17
-rw-r--r--fs/notify/inotify/inotify_user.c9
-rw-r--r--include/asm-generic/preempt.h3
-rw-r--r--include/linux/cpufreq.h6
-rw-r--r--include/linux/freezer.h50
-rw-r--r--include/linux/kernel.h5
-rw-r--r--include/linux/sched.h108
-rw-r--r--include/linux/wait.h80
-rw-r--r--include/net/sock.h1
-rw-r--r--include/trace/events/sched.h9
-rw-r--r--include/uapi/linux/sched.h6
-rw-r--r--kernel/audit.c11
-rw-r--r--kernel/context_tracking.c40
-rw-r--r--kernel/cpuset.c23
-rw-r--r--kernel/exit.c5
-rw-r--r--kernel/locking/mutex.c8
-rw-r--r--kernel/module.c30
-rw-r--r--kernel/sched/Makefile3
-rw-r--r--kernel/sched/completion.c5
-rw-r--r--kernel/sched/core.c290
-rw-r--r--kernel/sched/deadline.c130
-rw-r--r--kernel/sched/debug.c23
-rw-r--r--kernel/sched/energy_model.c341
-rw-r--r--kernel/sched/fair.c796
-rw-r--r--kernel/sched/features.h6
-rw-r--r--kernel/sched/rt.c14
-rw-r--r--kernel/sched/sched.h61
-rw-r--r--kernel/sched/wait.c66
-rw-r--r--kernel/smpboot.c15
-rw-r--r--kernel/sysctl.c3
-rw-r--r--net/bluetooth/rfcomm/core.c18
-rw-r--r--net/core/dev.c10
-rw-r--r--net/core/rtnetlink.c10
35 files changed, 1705 insertions, 522 deletions
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 7024c12f7bfe..8f3271842533 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -30,9 +30,6 @@ static __always_inline void preempt_count_set(int pc)
/*
* must be macros to avoid header recursion hell
*/
-#define task_preempt_count(p) \
- (task_thread_info(p)->saved_preempt_count & ~PREEMPT_NEED_RESCHED)
-
#define init_task_preempt_count(p) do { \
task_thread_info(p)->saved_preempt_count = PREEMPT_DISABLED; \
} while (0)
@@ -105,6 +102,7 @@ static __always_inline bool should_resched(void)
# ifdef CONFIG_CONTEXT_TRACKING
extern asmlinkage void ___preempt_schedule_context(void);
# define __preempt_schedule_context() asm ("call ___preempt_schedule_context")
+ extern asmlinkage void preempt_schedule_context(void);
# endif
#endif
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 3489f8f5fada..6520ff6461e1 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -102,6 +102,15 @@ config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
Be aware that not all cpufreq drivers support the conservative
governor. If unsure have a look at the help section of the
driver. Fallback governor will be the performance governor.
+
+config CPU_FREQ_DEFAULT_GOV_ENERGY_MODEL
+ bool "energy_model"
+ select CPU_FREQ_GOV_ENERGY_MODEL
+ select CPU_FREQ_GOV_PERFORMANCE
+ help
+ Use the CPUfreq governor 'energy_model' as default. This
+ scales cpu frequency from the scheduler as per-task statistics
+ are updated.
endchoice
config CPU_FREQ_GOV_PERFORMANCE
@@ -183,6 +192,18 @@ config CPU_FREQ_GOV_CONSERVATIVE
If in doubt, say N.
+config CPU_FREQ_GOV_ENERGY_MODEL
+ tristate "'energy model' cpufreq governor"
+ depends on CPU_FREQ
+ select CPU_FREQ_GOV_COMMON
+ help
+ 'energy_model' - this governor scales cpu frequency from the
+ scheduler as a function of cpu utilization. It does not
+ evaluate utilization on a periodic basis (unlike ondemand) but
+ instead is invoked from CFS when updating per-task statistics.
+
+ If in doubt, say N.
+
config CPUFREQ_DT
tristate "Generic DT based cpufreq driver"
depends on HAVE_CLK && OF
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 89c4cee253e3..fb3f519b803f 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2123,7 +2123,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
{
struct n_tty_data *ldata = tty->disc_data;
unsigned char __user *b = buf;
- DECLARE_WAITQUEUE(wait, current);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
int c;
int minimum, time;
ssize_t retval = 0;
@@ -2186,10 +2186,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
nr--;
break;
}
- /* This statement must be first before checking for input
- so that any interrupt will set the state back to
- TASK_RUNNING. */
- set_current_state(TASK_INTERRUPTIBLE);
if (((minimum - (b - buf)) < ldata->minimum_to_wake) &&
((minimum - (b - buf)) >= 1))
@@ -2220,13 +2216,13 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
n_tty_set_room(tty);
up_read(&tty->termios_rwsem);
- timeout = schedule_timeout(timeout);
+ timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
+ timeout);
down_read(&tty->termios_rwsem);
continue;
}
}
- __set_current_state(TASK_RUNNING);
/* Deal with packet mode. */
if (packet && b == buf) {
@@ -2273,7 +2269,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
mutex_unlock(&ldata->atomic_read_lock);
- __set_current_state(TASK_RUNNING);
if (b - buf)
retval = b - buf;
@@ -2306,7 +2301,7 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
const unsigned char *buf, size_t nr)
{
const unsigned char *b = buf;
- DECLARE_WAITQUEUE(wait, current);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
int c;
ssize_t retval = 0;
@@ -2324,7 +2319,6 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
add_wait_queue(&tty->write_wait, &wait);
while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
@@ -2378,12 +2372,11 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
}
up_read(&tty->termios_rwsem);
- schedule();
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
down_read(&tty->termios_rwsem);
}
break_out:
- __set_current_state(TASK_RUNNING);
remove_wait_queue(&tty->write_wait, &wait);
if (b - buf != nr && tty->fasync)
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index daf76652fe58..283aa312d745 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -227,14 +227,13 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
struct fsnotify_event *kevent;
char __user *start;
int ret;
- DEFINE_WAIT(wait);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
start = buf;
group = file->private_data;
+ add_wait_queue(&group->notification_waitq, &wait);
while (1) {
- prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE);
-
mutex_lock(&group->notification_mutex);
kevent = get_one_event(group, count);
mutex_unlock(&group->notification_mutex);
@@ -264,10 +263,10 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
if (start != buf)
break;
- schedule();
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
+ remove_wait_queue(&group->notification_waitq, &wait);
- finish_wait(&group->notification_waitq, &wait);
if (start != buf && ret != -EFAULT)
ret = buf - start;
return ret;
diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h
index 1cd3f5d767a8..eb6f9e6c3075 100644
--- a/include/asm-generic/preempt.h
+++ b/include/asm-generic/preempt.h
@@ -23,9 +23,6 @@ static __always_inline void preempt_count_set(int pc)
/*
* must be macros to avoid header recursion hell
*/
-#define task_preempt_count(p) \
- (task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED)
-
#define init_task_preempt_count(p) do { \
task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
} while (0)
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 503b085b7832..9ae4b27c2b4b 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -115,6 +115,9 @@ struct cpufreq_policy {
/* For cpufreq driver's internal use */
void *driver_data;
+
+ /* For cpufreq governor's internal use */
+ void *gov_data;
};
/* Only for ACPI */
@@ -481,6 +484,9 @@ extern struct cpufreq_governor cpufreq_gov_ondemand;
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
extern struct cpufreq_governor cpufreq_gov_conservative;
#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
+#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ENERGY_MODEL)
+extern struct cpufreq_governor cpufreq_gov_energy_model;
+#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_energy_model)
#endif
/*********************************************************************
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 7fd81b8c4897..6b7fd9cf5ea2 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -246,15 +246,6 @@ static inline int freezable_schedule_hrtimeout_range(ktime_t *expires,
* defined in <linux/wait.h>
*/
-#define wait_event_freezekillable(wq, condition) \
-({ \
- int __retval; \
- freezer_do_not_count(); \
- __retval = wait_event_killable(wq, (condition)); \
- freezer_count(); \
- __retval; \
-})
-
/* DO NOT ADD ANY NEW CALLERS OF THIS FUNCTION */
#define wait_event_freezekillable_unsafe(wq, condition) \
({ \
@@ -265,35 +256,6 @@ static inline int freezable_schedule_hrtimeout_range(ktime_t *expires,
__retval; \
})
-#define wait_event_freezable(wq, condition) \
-({ \
- int __retval; \
- freezer_do_not_count(); \
- __retval = wait_event_interruptible(wq, (condition)); \
- freezer_count(); \
- __retval; \
-})
-
-#define wait_event_freezable_timeout(wq, condition, timeout) \
-({ \
- long __retval = timeout; \
- freezer_do_not_count(); \
- __retval = wait_event_interruptible_timeout(wq, (condition), \
- __retval); \
- freezer_count(); \
- __retval; \
-})
-
-#define wait_event_freezable_exclusive(wq, condition) \
-({ \
- int __retval; \
- freezer_do_not_count(); \
- __retval = wait_event_interruptible_exclusive(wq, condition); \
- freezer_count(); \
- __retval; \
-})
-
-
#else /* !CONFIG_FREEZER */
static inline bool frozen(struct task_struct *p) { return false; }
static inline bool freezing(struct task_struct *p) { return false; }
@@ -331,18 +293,6 @@ static inline void set_freezable(void) {}
#define freezable_schedule_hrtimeout_range(expires, delta, mode) \
schedule_hrtimeout_range(expires, delta, mode)
-#define wait_event_freezable(wq, condition) \
- wait_event_interruptible(wq, condition)
-
-#define wait_event_freezable_timeout(wq, condition, timeout) \
- wait_event_interruptible_timeout(wq, condition, timeout)
-
-#define wait_event_freezable_exclusive(wq, condition) \
- wait_event_interruptible_exclusive(wq, condition)
-
-#define wait_event_freezekillable(wq, condition) \
- wait_event_killable(wq, condition)
-
#define wait_event_freezekillable_unsafe(wq, condition) \
wait_event_killable(wq, condition)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 3d770f5564b8..446d76a87ba1 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -162,6 +162,7 @@ extern int _cond_resched(void);
#endif
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
+ void ___might_sleep(const char *file, int line, int preempt_offset);
void __might_sleep(const char *file, int line, int preempt_offset);
/**
* might_sleep - annotation for functions that can sleep
@@ -175,10 +176,14 @@ extern int _cond_resched(void);
*/
# define might_sleep() \
do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
+# define sched_annotate_sleep() __set_current_state(TASK_RUNNING)
#else
+ static inline void ___might_sleep(const char *file, int line,
+ int preempt_offset) { }
static inline void __might_sleep(const char *file, int line,
int preempt_offset) { }
# define might_sleep() do { might_resched(); } while (0)
+# define sched_annotate_sleep() do { } while (0)
#endif
#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 50f8c6343f17..fc3a7cf107ec 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -243,6 +243,43 @@ extern char ___assert_task_state[1 - 2*!!(
((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
(task->flags & PF_FROZEN) == 0)
+#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
+
+#define __set_task_state(tsk, state_value) \
+ do { \
+ (tsk)->task_state_change = _THIS_IP_; \
+ (tsk)->state = (state_value); \
+ } while (0)
+#define set_task_state(tsk, state_value) \
+ do { \
+ (tsk)->task_state_change = _THIS_IP_; \
+ set_mb((tsk)->state, (state_value)); \
+ } while (0)
+
+/*
+ * set_current_state() includes a barrier so that the write of current->state
+ * is correctly serialised wrt the caller's subsequent test of whether to
+ * actually sleep:
+ *
+ * set_current_state(TASK_UNINTERRUPTIBLE);
+ * if (do_i_need_to_sleep())
+ * schedule();
+ *
+ * If the caller does not need such serialisation then use __set_current_state()
+ */
+#define __set_current_state(state_value) \
+ do { \
+ current->task_state_change = _THIS_IP_; \
+ current->state = (state_value); \
+ } while (0)
+#define set_current_state(state_value) \
+ do { \
+ current->task_state_change = _THIS_IP_; \
+ set_mb(current->state, (state_value)); \
+ } while (0)
+
+#else
+
#define __set_task_state(tsk, state_value) \
do { (tsk)->state = (state_value); } while (0)
#define set_task_state(tsk, state_value) \
@@ -259,11 +296,13 @@ extern char ___assert_task_state[1 - 2*!!(
*
* If the caller does not need such serialisation then use __set_current_state()
*/
-#define __set_current_state(state_value) \
+#define __set_current_state(state_value) \
do { current->state = (state_value); } while (0)
-#define set_current_state(state_value) \
+#define set_current_state(state_value) \
set_mb(current->state, (state_value))
+#endif
+
/* Task command name length */
#define TASK_COMM_LEN 16
@@ -1072,15 +1111,28 @@ struct load_weight {
};
struct sched_avg {
+ u64 last_runnable_update;
+ s64 decay_count;
+ /*
+ * utilization_avg_contrib describes the amount of time that a
+ * sched_entity is running on a CPU. It is based on running_avg_sum
+ * and is scaled in the range [0..SCHED_LOAD_SCALE].
+ * load_avg_contrib described the amount of time that a sched_entity
+ * is runnable on a rq. It is based on both runnable_avg_sum and the
+ * weight of the task.
+ */
+ unsigned long load_avg_contrib, utilization_avg_contrib;
/*
* These sums represent an infinite geometric series and so are bound
* above by 1024/(1-y). Thus we only need a u32 to store them for all
* choices of y < 1-2^(-32)*1024.
+ * running_avg_sum reflects the time that the sched_entity is
+ * effectively running on the CPU.
+ * runnable_avg_sum represents the amount of time a sched_entity is on
+ * a runqueue which includes the running time that is monitored by
+ * running_avg_sum.
*/
- u32 runnable_avg_sum, runnable_avg_period;
- u64 last_runnable_update;
- s64 decay_count;
- unsigned long load_avg_contrib;
+ u32 runnable_avg_sum, avg_period, running_avg_sum;
};
#ifdef CONFIG_SCHEDSTATS
@@ -1576,28 +1628,23 @@ struct task_struct {
struct numa_group *numa_group;
/*
- * Exponential decaying average of faults on a per-node basis.
- * Scheduling placement decisions are made based on the these counts.
- * The values remain static for the duration of a PTE scan
+ * numa_faults is an array split into four regions:
+ * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
+ * in this precise order.
+ *
+ * faults_memory: Exponential decaying average of faults on a per-node
+ * basis. Scheduling placement decisions are made based on these
+ * counts. The values remain static for the duration of a PTE scan.
+ * faults_cpu: Track the nodes the process was running on when a NUMA
+ * hinting fault was incurred.
+ * faults_memory_buffer and faults_cpu_buffer: Record faults per node
+ * during the current scan window. When the scan completes, the counts
+ * in faults_memory and faults_cpu decay and these values are copied.
*/
- unsigned long *numa_faults_memory;
+ unsigned long *numa_faults;
unsigned long total_numa_faults;
/*
- * numa_faults_buffer records faults per node during the current
- * scan window. When the scan completes, the counts in
- * numa_faults_memory decay and these values are copied.
- */
- unsigned long *numa_faults_buffer_memory;
-
- /*
- * Track the nodes the process was running on when a NUMA hinting
- * fault was incurred.
- */
- unsigned long *numa_faults_cpu;
- unsigned long *numa_faults_buffer_cpu;
-
- /*
* numa_faults_locality tracks if faults recorded during the last
* scan window were remote/local. The task scan period is adapted
* based on the locality of the faults with different weights
@@ -1682,6 +1729,9 @@ struct task_struct {
#ifdef CONFIG_SCHED_IO_LATENCY
struct io_latency_node io_latency;
#endif
+#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
+ unsigned long task_state_change;
+#endif
};
/* Future-safe accessor for struct task_struct's cpus_allowed. */
@@ -2073,6 +2123,10 @@ static inline void tsk_restore_flags(struct task_struct *task,
task->flags |= orig_flags & flags;
}
+extern int cpuset_cpumask_can_shrink(const struct cpumask *cur,
+ const struct cpumask *trial);
+extern int task_can_attach(struct task_struct *p,
+ const struct cpumask *cs_cpus_allowed);
#ifdef CONFIG_SMP
extern void do_set_cpus_allowed(struct task_struct *p,
const struct cpumask *new_mask);
@@ -2781,7 +2835,7 @@ static inline int signal_pending_state(long state, struct task_struct *p)
extern int _cond_resched(void);
#define cond_resched() ({ \
- __might_sleep(__FILE__, __LINE__, 0); \
+ ___might_sleep(__FILE__, __LINE__, 0); \
_cond_resched(); \
})
@@ -2794,14 +2848,14 @@ extern int __cond_resched_lock(spinlock_t *lock);
#endif
#define cond_resched_lock(lock) ({ \
- __might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET); \
+ ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
__cond_resched_lock(lock); \
})
extern int __cond_resched_softirq(void);
#define cond_resched_softirq() ({ \
- __might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
+ ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
__cond_resched_softirq(); \
})
diff --git a/include/linux/wait.h b/include/linux/wait.h
index e4a8eb9312ea..2232ed16635a 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -13,9 +13,12 @@ typedef struct __wait_queue wait_queue_t;
typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
+/* __wait_queue::flags */
+#define WQ_FLAG_EXCLUSIVE 0x01
+#define WQ_FLAG_WOKEN 0x02
+
struct __wait_queue {
unsigned int flags;
-#define WQ_FLAG_EXCLUSIVE 0x01
void *private;
wait_queue_func_t func;
struct list_head task_list;
@@ -258,11 +261,37 @@ __out: __ret; \
*/
#define wait_event(wq, condition) \
do { \
+ might_sleep(); \
if (condition) \
break; \
__wait_event(wq, condition); \
} while (0)
+#define __wait_event_freezable(wq, condition) \
+ ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \
+ schedule(); try_to_freeze())
+
+/**
+ * wait_event - sleep (or freeze) until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
+ * to system load) until the @condition evaluates to true. The
+ * @condition is checked each time the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define wait_event_freezable(wq, condition) \
+({ \
+ int __ret = 0; \
+ might_sleep(); \
+ if (!(condition)) \
+ __ret = __wait_event_freezable(wq, condition); \
+ __ret; \
+})
+
#define __wait_event_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_UNINTERRUPTIBLE, 0, timeout, \
@@ -290,11 +319,30 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
+ might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
+#define __wait_event_freezable_timeout(wq, condition, timeout) \
+ ___wait_event(wq, ___wait_cond_timeout(condition), \
+ TASK_INTERRUPTIBLE, 0, timeout, \
+ __ret = schedule_timeout(__ret); try_to_freeze())
+
+/*
+ * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
+ * increasing load and is freezable.
+ */
+#define wait_event_freezable_timeout(wq, condition, timeout) \
+({ \
+ long __ret = timeout; \
+ might_sleep(); \
+ if (!___wait_cond_timeout(condition)) \
+ __ret = __wait_event_freezable_timeout(wq, condition, timeout); \
+ __ret; \
+})
+
#define __wait_event_cmd(wq, condition, cmd1, cmd2) \
(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \
cmd1; schedule(); cmd2)
@@ -315,6 +363,7 @@ do { \
*/
#define wait_event_cmd(wq, condition, cmd1, cmd2) \
do { \
+ might_sleep(); \
if (condition) \
break; \
__wait_event_cmd(wq, condition, cmd1, cmd2); \
@@ -342,6 +391,7 @@ do { \
#define wait_event_interruptible(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_interruptible(wq, condition); \
__ret; \
@@ -375,6 +425,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
+ might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
@@ -425,6 +476,7 @@ do { \
#define wait_event_hrtimeout(wq, condition, timeout) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_hrtimeout(wq, condition, timeout, \
TASK_UNINTERRUPTIBLE); \
@@ -450,6 +502,7 @@ do { \
#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
({ \
long __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_hrtimeout(wq, condition, timeout, \
TASK_INTERRUPTIBLE); \
@@ -463,12 +516,27 @@ do { \
#define wait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_interruptible_exclusive(wq, condition);\
__ret; \
})
+#define __wait_event_freezable_exclusive(wq, condition) \
+ ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \
+ schedule(); try_to_freeze())
+
+#define wait_event_freezable_exclusive(wq, condition) \
+({ \
+ int __ret = 0; \
+ might_sleep(); \
+ if (!(condition)) \
+ __ret = __wait_event_freezable_exclusive(wq, condition);\
+ __ret; \
+})
+
+
#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
({ \
int __ret = 0; \
@@ -637,6 +705,7 @@ do { \
#define wait_event_killable(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_killable(wq, condition); \
__ret; \
@@ -830,6 +899,8 @@ void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int sta
long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state);
void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key);
+long wait_woken(wait_queue_t *wait, unsigned mode, long timeout);
+int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
@@ -886,6 +957,7 @@ extern int bit_wait_io_timeout(struct wait_bit_key *);
static inline int
wait_on_bit(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit,
@@ -910,6 +982,7 @@ wait_on_bit(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_io(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit,
@@ -936,6 +1009,7 @@ wait_on_bit_io(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit, action, mode);
@@ -963,6 +1037,7 @@ wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode
static inline int
wait_on_bit_lock(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode);
@@ -986,6 +1061,7 @@ wait_on_bit_lock(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_lock_io(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode);
@@ -1011,6 +1087,7 @@ wait_on_bit_lock_io(void *word, int bit, unsigned mode)
static inline int
wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, action, mode);
@@ -1029,6 +1106,7 @@ wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned
static inline
int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
{
+ might_sleep();
if (atomic_read(val) == 0)
return 0;
return out_of_line_wait_on_atomic_t(val, action, mode);
diff --git a/include/net/sock.h b/include/net/sock.h
index 7db3db112baa..e6f235ebf6c9 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -897,6 +897,7 @@ static inline void sock_rps_reset_rxhash(struct sock *sk)
if (!__rc) { \
*(__timeo) = schedule_timeout(*(__timeo)); \
} \
+ sched_annotate_sleep(); \
lock_sock(__sk); \
__rc = __condition; \
__rc; \
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index 0a68d5ae584e..30fedaf3e56a 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -97,16 +97,19 @@ static inline long __trace_sched_switch_state(struct task_struct *p)
long state = p->state;
#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_SCHED_DEBUG
+ BUG_ON(p != current);
+#endif /* CONFIG_SCHED_DEBUG */
/*
* For all intents and purposes a preempted task is a running task.
*/
- if (task_preempt_count(p) & PREEMPT_ACTIVE)
+ if (preempt_count() & PREEMPT_ACTIVE)
state = TASK_RUNNING | TASK_STATE_MAX;
-#endif
+#endif /* CONFIG_PREEMPT */
return state;
}
-#endif
+#endif /* CREATE_TRACE_POINTS */
/*
* Tracepoint for task switches, performed by the scheduler:
diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
index 34f9d7387d13..cc89ddefa926 100644
--- a/include/uapi/linux/sched.h
+++ b/include/uapi/linux/sched.h
@@ -13,7 +13,7 @@
#define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */
#define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */
#define CLONE_THREAD 0x00010000 /* Same thread group? */
-#define CLONE_NEWNS 0x00020000 /* New namespace group? */
+#define CLONE_NEWNS 0x00020000 /* New mount namespace group */
#define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */
#define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */
#define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */
@@ -23,8 +23,8 @@
#define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
/* 0x02000000 was previously the unused CLONE_STOPPED (Start in stopped state)
and is now available for re-use. */
-#define CLONE_NEWUTS 0x04000000 /* New utsname group? */
-#define CLONE_NEWIPC 0x08000000 /* New ipcs */
+#define CLONE_NEWUTS 0x04000000 /* New utsname namespace */
+#define CLONE_NEWIPC 0x08000000 /* New ipc namespace */
#define CLONE_NEWUSER 0x10000000 /* New user namespace */
#define CLONE_NEWPID 0x20000000 /* New pid namespace */
#define CLONE_NEWNET 0x40000000 /* New network namespace */
diff --git a/kernel/audit.c b/kernel/audit.c
index 80983df92cd4..32bfc43ffb9a 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -499,7 +499,6 @@ static int kauditd_thread(void *dummy)
set_freezable();
while (!kthread_should_stop()) {
struct sk_buff *skb;
- DECLARE_WAITQUEUE(wait, current);
flush_hold_queue();
@@ -514,16 +513,8 @@ static int kauditd_thread(void *dummy)
audit_printk_skb(skb);
continue;
}
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&kauditd_wait, &wait);
- if (!skb_queue_len(&audit_skb_queue)) {
- try_to_freeze();
- schedule();
- }
-
- __set_current_state(TASK_RUNNING);
- remove_wait_queue(&kauditd_wait, &wait);
+ wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue));
}
return 0;
}
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 5664985c46a0..937ecdfdf258 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -107,46 +107,6 @@ void context_tracking_user_enter(void)
}
NOKPROBE_SYMBOL(context_tracking_user_enter);
-#ifdef CONFIG_PREEMPT
-/**
- * preempt_schedule_context - preempt_schedule called by tracing
- *
- * The tracing infrastructure uses preempt_enable_notrace to prevent
- * recursion and tracing preempt enabling caused by the tracing
- * infrastructure itself. But as tracing can happen in areas coming
- * from userspace or just about to enter userspace, a preempt enable
- * can occur before user_exit() is called. This will cause the scheduler
- * to be called when the system is still in usermode.
- *
- * To prevent this, the preempt_enable_notrace will use this function
- * instead of preempt_schedule() to exit user context if needed before
- * calling the scheduler.
- */
-asmlinkage __visible void __sched notrace preempt_schedule_context(void)
-{
- enum ctx_state prev_ctx;
-
- if (likely(!preemptible()))
- return;
-
- /*
- * Need to disable preemption in case user_exit() is traced
- * and the tracer calls preempt_enable_notrace() causing
- * an infinite recursion.
- */
- preempt_disable_notrace();
- prev_ctx = exception_enter();
- preempt_enable_no_resched_notrace();
-
- preempt_schedule();
-
- preempt_disable_notrace();
- exception_exit(prev_ctx);
- preempt_enable_notrace();
-}
-EXPORT_SYMBOL_GPL(preempt_schedule_context);
-#endif /* CONFIG_PREEMPT */
-
/**
* context_tracking_user_exit - Inform the context tracking that the CPU is
* exiting userspace mode and entering the kernel.
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1f107c74087b..723cfc9d0ad7 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -506,6 +506,16 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
goto out;
}
+ /*
+ * We can't shrink if we won't have enough room for SCHED_DEADLINE
+ * tasks.
+ */
+ ret = -EBUSY;
+ if (is_cpu_exclusive(cur) &&
+ !cpuset_cpumask_can_shrink(cur->cpus_allowed,
+ trial->cpus_allowed))
+ goto out;
+
ret = 0;
out:
rcu_read_unlock();
@@ -1429,17 +1439,8 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
goto out_unlock;
cgroup_taskset_for_each(task, tset) {
- /*
- * Kthreads which disallow setaffinity shouldn't be moved
- * to a new cpuset; we don't want to change their cpu
- * affinity and isolating such threads by their set of
- * allowed nodes is unnecessary. Thus, cpusets are not
- * applicable for such threads. This prevents checking for
- * success of set_cpus_allowed_ptr() on all attached tasks
- * before cpus_allowed may be changed.
- */
- ret = -EINVAL;
- if (task->flags & PF_NO_SETAFFINITY)
+ ret = task_can_attach(task, cs->cpus_allowed);
+ if (ret)
goto out_unlock;
ret = security_task_setscheduler(task);
if (ret)
diff --git a/kernel/exit.c b/kernel/exit.c
index 123419be6f84..8e4e75d5efaa 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -998,6 +998,8 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
get_task_struct(p);
read_unlock(&tasklist_lock);
+ sched_annotate_sleep();
+
if ((exit_code & 0x7f) == 0) {
why = CLD_EXITED;
status = exit_code >> 8;
@@ -1080,6 +1082,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
* thread can reap it because we its state == DEAD/TRACE.
*/
read_unlock(&tasklist_lock);
+ sched_annotate_sleep();
retval = wo->wo_rusage
? getrusage(p, RUSAGE_BOTH, wo->wo_rusage) : 0;
@@ -1211,6 +1214,7 @@ unlock_sig:
pid = task_pid_vnr(p);
why = ptrace ? CLD_TRAPPED : CLD_STOPPED;
read_unlock(&tasklist_lock);
+ sched_annotate_sleep();
if (unlikely(wo->wo_flags & WNOWAIT))
return wait_noreap_copyout(wo, p, pid, uid, why, exit_code);
@@ -1273,6 +1277,7 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
pid = task_pid_vnr(p);
get_task_struct(p);
read_unlock(&tasklist_lock);
+ sched_annotate_sleep();
if (!wo->wo_info) {
retval = wo->wo_rusage
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index dadbf88c22c4..454195194d4a 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -378,8 +378,14 @@ done:
* reschedule now, before we try-lock the mutex. This avoids getting
* scheduled out right after we obtained the mutex.
*/
- if (need_resched())
+ if (need_resched()) {
+ /*
+ * We _should_ have TASK_RUNNING here, but just in case
+ * we do not, make it so, otherwise we might get stuck.
+ */
+ __set_current_state(TASK_RUNNING);
schedule_preempt_disabled();
+ }
return false;
}
diff --git a/kernel/module.c b/kernel/module.c
index 88cec1ddb1e3..e52a8739361a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3097,6 +3097,32 @@ static int may_init_module(void)
}
/*
+ * Can't use wait_event_interruptible() because our condition
+ * 'finished_loading()' contains a blocking primitive itself (mutex_lock).
+ */
+static int wait_finished_loading(struct module *mod)
+{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ int ret = 0;
+
+ add_wait_queue(&module_wq, &wait);
+ for (;;) {
+ if (finished_loading(mod->name))
+ break;
+
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+ }
+ remove_wait_queue(&module_wq, &wait);
+
+ return ret;
+}
+
+/*
* We try to place it in the list now to make sure it's unique before
* we dedicate too many resources. In particular, temporary percpu
* memory exhaustion.
@@ -3116,8 +3142,8 @@ again:
|| old->state == MODULE_STATE_UNFORMED) {
/* Wait in case it fails to load. */
mutex_unlock(&module_mutex);
- err = wait_event_interruptible(module_wq,
- finished_loading(mod->name));
+
+ err = wait_finished_loading(mod);
if (err)
goto out_unlocked;
goto again;
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 622511a4e49e..5d5380090741 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -20,4 +20,5 @@ obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
obj-$(CONFIG_SCHED_IO_LATENCY) += io_latency.o
-obj-$(CONFIG_SCHED_IDLE_DEBUG) += idle_debug.o \ No newline at end of file
+obj-$(CONFIG_SCHED_IDLE_DEBUG) += idle_debug.o
+obj-$(CONFIG_CPU_FREQ_GOV_ENERGY_MODEL) += energy_model.o
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index a63f4dc27909..607f852b4d04 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -148,7 +148,7 @@ EXPORT_SYMBOL(wait_for_completion_timeout);
*
* This waits to be signaled for completion of a specific task. It is NOT
* interruptible and there is no timeout. The caller is accounted as waiting
- * for IO.
+ * for IO (which traditionally means blkio only).
*/
void __sched wait_for_completion_io(struct completion *x)
{
@@ -163,7 +163,8 @@ EXPORT_SYMBOL(wait_for_completion_io);
*
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. The timeout is in jiffies. It is not
- * interruptible. The caller is accounted as waiting for IO.
+ * interruptible. The caller is accounted as waiting for IO (which traditionally
+ * means blkio only).
*
* Return: 0 if timed out, and positive (at least 1, or number of jiffies left
* till timeout) if completed.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 827ddf978f38..4db493445cd6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1009,6 +1009,9 @@ inline int task_curr(const struct task_struct *p)
return cpu_curr(task_cpu(p)) == p;
}
+/*
+ * Can drop rq->lock because from sched_class::switched_from() methods drop it.
+ */
static inline void check_class_changed(struct rq *rq, struct task_struct *p,
const struct sched_class *prev_class,
int oldprio)
@@ -1016,6 +1019,7 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
if (prev_class != p->sched_class) {
if (prev_class->switched_from)
prev_class->switched_from(rq, p);
+ /* Possble rq->lock 'hole'. */
p->sched_class->switched_to(rq, p);
} else if (oldprio != p->prio || dl_task(p))
p->sched_class->prio_changed(rq, p, oldprio);
@@ -1055,7 +1059,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
* ttwu() will sort out the placement.
*/
WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
- !(task_preempt_count(p) & PREEMPT_ACTIVE));
+ !p->on_rq);
#ifdef CONFIG_LOCKDEP
/*
@@ -1854,8 +1858,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
p->numa_scan_period = sysctl_numa_balancing_scan_delay;
p->numa_work.next = &p->numa_work;
- p->numa_faults_memory = NULL;
- p->numa_faults_buffer_memory = NULL;
+ p->numa_faults = NULL;
p->last_task_numa_placement = 0;
p->last_sum_exec_runtime = 0;
@@ -2035,25 +2038,6 @@ static inline int dl_bw_cpus(int i)
}
#endif
-static inline
-void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
-{
- dl_b->total_bw -= tsk_bw;
-}
-
-static inline
-void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
-{
- dl_b->total_bw += tsk_bw;
-}
-
-static inline
-bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
-{
- return dl_b->bw != -1 &&
- dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
-}
-
/*
* We must be sure that accepting a new task (or allowing changing the
* parameters of an existing one) is consistent with the bandwidth
@@ -2221,7 +2205,6 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
/**
* finish_task_switch - clean up after a task-switch
- * @rq: runqueue associated with task-switch
* @prev: the thread we just switched away from.
*
* finish_task_switch must be called after the context switch, paired
@@ -2233,10 +2216,16 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
* so, we finish that here outside of the runqueue lock. (Doing it
* with the lock held can cause deadlocks; see schedule() for
* details.)
+ *
+ * The context switch have flipped the stack from under us and restored the
+ * local variables which were saved when this task called schedule() in the
+ * past. prev == current is still correct but we need to recalculate this_rq
+ * because prev may have moved to another CPU.
*/
-static void finish_task_switch(struct rq *rq, struct task_struct *prev)
+static struct rq *finish_task_switch(struct task_struct *prev)
__releases(rq->lock)
{
+ struct rq *rq = this_rq();
struct mm_struct *mm = rq->prev_mm;
long prev_state;
@@ -2276,6 +2265,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
}
tick_nohz_task_switch(current);
+ return rq;
}
#ifdef CONFIG_SMP
@@ -2310,25 +2300,22 @@ static inline void post_schedule(struct rq *rq)
asmlinkage __visible void schedule_tail(struct task_struct *prev)
__releases(rq->lock)
{
- struct rq *rq = this_rq();
-
- finish_task_switch(rq, prev);
+ struct rq *rq;
- /*
- * FIXME: do we need to worry about rq being invalidated by the
- * task_switch?
- */
+ /* finish_task_switch() drops rq->lock and enables preemtion */
+ preempt_disable();
+ rq = finish_task_switch(prev);
post_schedule(rq);
+ preempt_enable();
if (current->set_child_tid)
put_user(task_pid_vnr(current), current->set_child_tid);
}
/*
- * context_switch - switch to the new MM and the new
- * thread's register state.
+ * context_switch - switch to the new MM and the new thread's register state.
*/
-static inline void
+static inline struct rq *
context_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
@@ -2367,14 +2354,9 @@ context_switch(struct rq *rq, struct task_struct *prev,
context_tracking_task_switch(prev, next);
/* Here we just switch the register state and the stack. */
switch_to(prev, next, prev);
-
barrier();
- /*
- * this_rq must be evaluated again because prev may have moved
- * CPUs since it called schedule(), thus the 'rq' on its stack
- * frame will be invalid.
- */
- finish_task_switch(this_rq(), prev);
+
+ return finish_task_switch(prev);
}
/*
@@ -2856,15 +2838,8 @@ need_resched:
rq->curr = next;
++*switch_count;
- context_switch(rq, prev, next); /* unlocks the rq */
- /*
- * The context switch have flipped the stack from under us
- * and restored the local variables which were saved when
- * this task called schedule() in the past. prev == current
- * is still correct, but it can be moved to another cpu/rq.
- */
- cpu = smp_processor_id();
- rq = cpu_rq(cpu);
+ rq = context_switch(rq, prev, next); /* unlocks the rq */
+ cpu = cpu_of(rq);
} else
raw_spin_unlock_irq(&rq->lock);
@@ -2952,6 +2927,47 @@ asmlinkage __visible void __sched notrace preempt_schedule(void)
}
NOKPROBE_SYMBOL(preempt_schedule);
EXPORT_SYMBOL(preempt_schedule);
+
+#ifdef CONFIG_CONTEXT_TRACKING
+/**
+ * preempt_schedule_context - preempt_schedule called by tracing
+ *
+ * The tracing infrastructure uses preempt_enable_notrace to prevent
+ * recursion and tracing preempt enabling caused by the tracing
+ * infrastructure itself. But as tracing can happen in areas coming
+ * from userspace or just about to enter userspace, a preempt enable
+ * can occur before user_exit() is called. This will cause the scheduler
+ * to be called when the system is still in usermode.
+ *
+ * To prevent this, the preempt_enable_notrace will use this function
+ * instead of preempt_schedule() to exit user context if needed before
+ * calling the scheduler.
+ */
+asmlinkage __visible void __sched notrace preempt_schedule_context(void)
+{
+ enum ctx_state prev_ctx;
+
+ if (likely(!preemptible()))
+ return;
+
+ do {
+ __preempt_count_add(PREEMPT_ACTIVE);
+ /*
+ * Needs preempt disabled in case user_exit() is traced
+ * and the tracer calls preempt_enable_notrace() causing
+ * an infinite recursion.
+ */
+ prev_ctx = exception_enter();
+ __schedule();
+ exception_exit(prev_ctx);
+
+ __preempt_count_sub(PREEMPT_ACTIVE);
+ barrier();
+ } while (need_resched());
+}
+EXPORT_SYMBOL_GPL(preempt_schedule_context);
+#endif /* CONFIG_CONTEXT_TRACKING */
+
#endif /* CONFIG_PREEMPT */
/*
@@ -4642,6 +4658,81 @@ void init_idle(struct task_struct *idle, int cpu)
#endif
}
+int cpuset_cpumask_can_shrink(const struct cpumask *cur,
+ const struct cpumask *trial)
+{
+ int ret = 1, trial_cpus;
+ struct dl_bw *cur_dl_b;
+ unsigned long flags;
+
+ rcu_read_lock_sched();
+ cur_dl_b = dl_bw_of(cpumask_any(cur));
+ trial_cpus = cpumask_weight(trial);
+
+ raw_spin_lock_irqsave(&cur_dl_b->lock, flags);
+ if (cur_dl_b->bw != -1 &&
+ cur_dl_b->bw * trial_cpus < cur_dl_b->total_bw)
+ ret = 0;
+ raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags);
+ rcu_read_unlock_sched();
+
+ return ret;
+}
+
+int task_can_attach(struct task_struct *p,
+ const struct cpumask *cs_cpus_allowed)
+{
+ int ret = 0;
+
+ /*
+ * Kthreads which disallow setaffinity shouldn't be moved
+ * to a new cpuset; we don't want to change their cpu
+ * affinity and isolating such threads by their set of
+ * allowed nodes is unnecessary. Thus, cpusets are not
+ * applicable for such threads. This prevents checking for
+ * success of set_cpus_allowed_ptr() on all attached tasks
+ * before cpus_allowed may be changed.
+ */
+ if (p->flags & PF_NO_SETAFFINITY) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+#ifdef CONFIG_SMP
+ if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span,
+ cs_cpus_allowed)) {
+ unsigned int dest_cpu = cpumask_any_and(cpu_active_mask,
+ cs_cpus_allowed);
+ struct dl_bw *dl_b;
+ bool overflow;
+ int cpus;
+ unsigned long flags;
+
+ rcu_read_lock_sched();
+ dl_b = dl_bw_of(dest_cpu);
+ raw_spin_lock_irqsave(&dl_b->lock, flags);
+ cpus = dl_bw_cpus(dest_cpu);
+ overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);
+ if (overflow)
+ ret = -EBUSY;
+ else {
+ /*
+ * We reserve space for this task in the destination
+ * root_domain, as we can't fail after this point.
+ * We will free resources in the source root_domain
+ * later on (see set_cpus_allowed_dl()).
+ */
+ __dl_add(dl_b, p->dl.dl_bw);
+ }
+ raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+ rcu_read_unlock_sched();
+
+ }
+#endif
+out:
+ return ret;
+}
+
#ifdef CONFIG_SMP
/*
* move_queued_task - move a queued task to new rq.
@@ -5374,17 +5465,6 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
break;
}
- /*
- * Even though we initialize ->capacity to something semi-sane,
- * we leave capacity_orig unset. This allows us to detect if
- * domain iteration is still funny without causing /0 traps.
- */
- if (!group->sgc->capacity_orig) {
- printk(KERN_CONT "\n");
- printk(KERN_ERR "ERROR: domain->cpu_capacity not set\n");
- break;
- }
-
if (!cpumask_weight(sched_group_cpus(group))) {
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: empty group\n");
@@ -5869,7 +5949,6 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
* die on a /0 trap.
*/
sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span);
- sg->sgc->capacity_orig = sg->sgc->capacity;
/*
* Make sure the first group of this domain contains the
@@ -6092,7 +6171,9 @@ static void claim_allocations(int cpu, struct sched_domain *sd)
#ifdef CONFIG_NUMA
static int sched_domains_numa_levels;
+enum numa_topology_type sched_numa_topology_type;
static int *sched_domains_numa_distance;
+int sched_max_numa_distance;
static struct cpumask ***sched_domains_numa_masks;
static int sched_domains_curr_level;
#endif
@@ -6178,6 +6259,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu)
*/
if (sd->flags & SD_SHARE_CPUCAPACITY) {
+ sd->flags |= SD_PREFER_SIBLING;
sd->imbalance_pct = 110;
sd->smt_gain = 1178; /* ~15% */
@@ -6264,7 +6346,7 @@ static void sched_numa_warn(const char *str)
printk(KERN_WARNING "\n");
}
-static bool find_numa_distance(int distance)
+bool find_numa_distance(int distance)
{
int i;
@@ -6279,6 +6361,56 @@ static bool find_numa_distance(int distance)
return false;
}
+/*
+ * A system can have three types of NUMA topology:
+ * NUMA_DIRECT: all nodes are directly connected, or not a NUMA system
+ * NUMA_GLUELESS_MESH: some nodes reachable through intermediary nodes
+ * NUMA_BACKPLANE: nodes can reach other nodes through a backplane
+ *
+ * The difference between a glueless mesh topology and a backplane
+ * topology lies in whether communication between not directly
+ * connected nodes goes through intermediary nodes (where programs
+ * could run), or through backplane controllers. This affects
+ * placement of programs.
+ *
+ * The type of topology can be discerned with the following tests:
+ * - If the maximum distance between any nodes is 1 hop, the system
+ * is directly connected.
+ * - If for two nodes A and B, located N > 1 hops away from each other,
+ * there is an intermediary node C, which is < N hops away from both
+ * nodes A and B, the system is a glueless mesh.
+ */
+static void init_numa_topology_type(void)
+{
+ int a, b, c, n;
+
+ n = sched_max_numa_distance;
+
+ if (n <= 1)
+ sched_numa_topology_type = NUMA_DIRECT;
+
+ for_each_online_node(a) {
+ for_each_online_node(b) {
+ /* Find two nodes furthest removed from each other. */
+ if (node_distance(a, b) < n)
+ continue;
+
+ /* Is there an intermediary node between a and b? */
+ for_each_online_node(c) {
+ if (node_distance(a, c) < n &&
+ node_distance(b, c) < n) {
+ sched_numa_topology_type =
+ NUMA_GLUELESS_MESH;
+ return;
+ }
+ }
+
+ sched_numa_topology_type = NUMA_BACKPLANE;
+ return;
+ }
+ }
+}
+
static void sched_init_numa(void)
{
int next_distance, curr_distance = node_distance(0, 0);
@@ -6411,6 +6543,9 @@ static void sched_init_numa(void)
sched_domain_topology = tl;
sched_domains_numa_levels = level;
+ sched_max_numa_distance = sched_domains_numa_distance[level - 1];
+
+ init_numa_topology_type();
}
static void sched_domains_numa_masks_set(int cpu)
@@ -7090,7 +7225,7 @@ void __init sched_init(void)
#ifdef CONFIG_SMP
rq->sd = NULL;
rq->rd = NULL;
- rq->cpu_capacity = SCHED_CAPACITY_SCALE;
+ rq->cpu_capacity = rq->cpu_capacity_orig = SCHED_CAPACITY_SCALE;
rq->post_schedule = 0;
rq->active_balance = 0;
rq->next_balance = jiffies;
@@ -7165,6 +7300,25 @@ static inline int preempt_count_equals(int preempt_offset)
void __might_sleep(const char *file, int line, int preempt_offset)
{
+ /*
+ * Blocking primitives will set (and therefore destroy) current->state,
+ * since we will exit with TASK_RUNNING make sure we enter with it,
+ * otherwise we will destroy state.
+ */
+ if (WARN_ONCE(current->state != TASK_RUNNING,
+ "do not call blocking ops when !TASK_RUNNING; "
+ "state=%lx set at [<%p>] %pS\n",
+ current->state,
+ (void *)current->task_state_change,
+ (void *)current->task_state_change))
+ __set_current_state(TASK_RUNNING);
+
+ ___might_sleep(file, line, preempt_offset);
+}
+EXPORT_SYMBOL(__might_sleep);
+
+void ___might_sleep(const char *file, int line, int preempt_offset)
+{
static unsigned long prev_jiffy; /* ratelimiting */
rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
@@ -7196,7 +7350,7 @@ void __might_sleep(const char *file, int line, int preempt_offset)
#endif
dump_stack();
}
-EXPORT_SYMBOL(__might_sleep);
+EXPORT_SYMBOL(___might_sleep);
#endif
#ifdef CONFIG_MAGIC_SYSRQ
@@ -7840,6 +7994,11 @@ static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css)
sched_offline_group(tg);
}
+static void cpu_cgroup_fork(struct task_struct *task)
+{
+ sched_move_task(task);
+}
+
static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
struct cgroup_taskset *tset)
{
@@ -8212,6 +8371,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.css_free = cpu_cgroup_css_free,
.css_online = cpu_cgroup_css_online,
.css_offline = cpu_cgroup_css_offline,
+ .fork = cpu_cgroup_fork,
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
.exit = cpu_cgroup_exit,
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 256e577faf1b..f3d7776656ee 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -518,12 +518,20 @@ again:
}
/*
- * We need to take care of a possible races here. In fact, the
- * task might have changed its scheduling policy to something
- * different from SCHED_DEADLINE or changed its reservation
- * parameters (through sched_setattr()).
+ * We need to take care of several possible races here:
+ *
+ * - the task might have changed its scheduling policy
+ * to something different than SCHED_DEADLINE
+ * - the task might have changed its reservation parameters
+ * (through sched_setattr())
+ * - the task might have been boosted by someone else and
+ * might be in the boosting/deboosting path
+ *
+ * In all this cases we bail out, as the task is already
+ * in the runqueue or is going to be enqueued back anyway.
*/
- if (!dl_task(p) || dl_se->dl_new)
+ if (!dl_task(p) || dl_se->dl_new ||
+ dl_se->dl_boosted || !dl_se->dl_throttled)
goto unlock;
sched_clock_tick();
@@ -532,7 +540,7 @@ again:
dl_se->dl_yielded = 0;
if (task_on_rq_queued(p)) {
enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
- if (task_has_dl_policy(rq->curr))
+ if (dl_task(rq->curr))
check_preempt_curr_dl(rq, p, 0);
else
resched_curr(rq);
@@ -555,11 +563,6 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se)
{
struct hrtimer *timer = &dl_se->dl_timer;
- if (hrtimer_active(timer)) {
- hrtimer_try_to_cancel(timer);
- return;
- }
-
hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
timer->function = dl_task_timer;
}
@@ -625,7 +628,7 @@ static void update_curr_dl(struct rq *rq)
sched_rt_avg_update(rq, delta_exec);
- dl_se->runtime -= delta_exec;
+ dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec;
if (dl_runtime_exceeded(rq, dl_se)) {
__dequeue_task_dl(rq, curr, 0);
if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted)))
@@ -847,8 +850,19 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags)
* smaller than our one... OTW we keep our runtime and
* deadline.
*/
- if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio))
+ if (pi_task && p->dl.dl_boosted && dl_prio(pi_task->normal_prio)) {
pi_se = &pi_task->dl;
+ } else if (!dl_prio(p->normal_prio)) {
+ /*
+ * Special case in which we have a !SCHED_DEADLINE task
+ * that is going to be deboosted, but exceedes its
+ * runtime while doing so. No point in replenishing
+ * it, as it's going to return back to its original
+ * scheduling class after this.
+ */
+ BUG_ON(!p->dl.dl_boosted || flags != ENQUEUE_REPLENISH);
+ return;
+ }
/*
* If p is throttled, we do nothing. In fact, if it exhausted
@@ -914,7 +928,10 @@ select_task_rq_dl(struct task_struct *p, int cpu, int sd_flag, int flags)
struct task_struct *curr;
struct rq *rq;
- if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
+ if (p->nr_cpus_allowed == 1)
+ goto out;
+
+ if (sd_flag != SD_BALANCE_WAKE)
goto out;
rq = cpu_rq(cpu);
@@ -1489,7 +1506,7 @@ static void task_woken_dl(struct rq *rq, struct task_struct *p)
p->nr_cpus_allowed > 1 &&
dl_task(rq->curr) &&
(rq->curr->nr_cpus_allowed < 2 ||
- dl_entity_preempt(&rq->curr->dl, &p->dl))) {
+ !dl_entity_preempt(&p->dl, &rq->curr->dl))) {
push_dl_tasks(rq);
}
}
@@ -1498,10 +1515,33 @@ static void set_cpus_allowed_dl(struct task_struct *p,
const struct cpumask *new_mask)
{
struct rq *rq;
+ struct root_domain *src_rd;
int weight;
BUG_ON(!dl_task(p));
+ rq = task_rq(p);
+ src_rd = rq->rd;
+ /*
+ * Migrating a SCHED_DEADLINE task between exclusive
+ * cpusets (different root_domains) entails a bandwidth
+ * update. We already made space for us in the destination
+ * domain (see cpuset_can_attach()).
+ */
+ if (!cpumask_intersects(src_rd->span, new_mask)) {
+ struct dl_bw *src_dl_b;
+
+ src_dl_b = dl_bw_of(cpu_of(rq));
+ /*
+ * We now free resources of the root_domain we are migrating
+ * off. In the worst case, sched_setattr() may temporary fail
+ * until we complete the update.
+ */
+ raw_spin_lock(&src_dl_b->lock);
+ __dl_clear(src_dl_b, p->dl.dl_bw);
+ raw_spin_unlock(&src_dl_b->lock);
+ }
+
/*
* Update only if the task is actually running (i.e.,
* it is on the rq AND it is not throttled).
@@ -1518,8 +1558,6 @@ static void set_cpus_allowed_dl(struct task_struct *p,
if ((p->nr_cpus_allowed > 1) == (weight > 1))
return;
- rq = task_rq(p);
-
/*
* The process used to be able to migrate OR it can now migrate
*/
@@ -1567,22 +1605,48 @@ void init_sched_dl_class(void)
#endif /* CONFIG_SMP */
+/*
+ * Ensure p's dl_timer is cancelled. May drop rq->lock for a while.
+ */
+static void cancel_dl_timer(struct rq *rq, struct task_struct *p)
+{
+ struct hrtimer *dl_timer = &p->dl.dl_timer;
+
+ /* Nobody will change task's class if pi_lock is held */
+ lockdep_assert_held(&p->pi_lock);
+
+ if (hrtimer_active(dl_timer)) {
+ int ret = hrtimer_try_to_cancel(dl_timer);
+
+ if (unlikely(ret == -1)) {
+ /*
+ * Note, p may migrate OR new deadline tasks
+ * may appear in rq when we are unlocking it.
+ * A caller of us must be fine with that.
+ */
+ raw_spin_unlock(&rq->lock);
+ hrtimer_cancel(dl_timer);
+ raw_spin_lock(&rq->lock);
+ }
+ }
+}
+
static void switched_from_dl(struct rq *rq, struct task_struct *p)
{
- if (hrtimer_active(&p->dl.dl_timer) && !dl_policy(p->policy))
- hrtimer_try_to_cancel(&p->dl.dl_timer);
+ cancel_dl_timer(rq, p);
__dl_clear_params(p);
-#ifdef CONFIG_SMP
/*
* Since this might be the only -deadline task on the rq,
* this is the right place to try to pull some other one
* from an overloaded cpu, if any.
*/
- if (!rq->dl.dl_nr_running)
- pull_dl_task(rq);
-#endif
+ if (!task_on_rq_queued(p) || rq->dl.dl_nr_running)
+ return;
+
+ if (pull_dl_task(rq))
+ resched_curr(rq);
}
/*
@@ -1603,12 +1667,17 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
- if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p))
+ if (p->nr_cpus_allowed > 1 && rq->dl.overloaded &&
+ push_dl_task(rq) && rq != task_rq(p))
/* Only reschedule if pushing failed */
check_resched = 0;
#endif /* CONFIG_SMP */
- if (check_resched && task_has_dl_policy(rq->curr))
- check_preempt_curr_dl(rq, p, 0);
+ if (check_resched) {
+ if (dl_task(rq->curr))
+ check_preempt_curr_dl(rq, p, 0);
+ else
+ resched_curr(rq);
+ }
}
}
@@ -1679,3 +1748,12 @@ const struct sched_class dl_sched_class = {
.switched_from = switched_from_dl,
.switched_to = switched_to_dl,
};
+
+#ifdef CONFIG_SCHED_DEBUG
+extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
+
+void print_dl_stats(struct seq_file *m, int cpu)
+{
+ print_dl_rq(m, cpu, &cpu_rq(cpu)->dl);
+}
+#endif /* CONFIG_SCHED_DEBUG */
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index ce33780d8f20..9dce8b5abeea 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -71,7 +71,7 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
if (!se) {
struct sched_avg *avg = &cpu_rq(cpu)->avg;
P(avg->runnable_avg_sum);
- P(avg->runnable_avg_period);
+ P(avg->avg_period);
return;
}
@@ -94,8 +94,10 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
P(se->load.weight);
#ifdef CONFIG_SMP
P(se->avg.runnable_avg_sum);
- P(se->avg.runnable_avg_period);
+ P(se->avg.running_avg_sum);
+ P(se->avg.avg_period);
P(se->avg.load_avg_contrib);
+ P(se->avg.utilization_avg_contrib);
P(se->avg.decay_count);
#endif
#undef PN
@@ -214,6 +216,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
cfs_rq->runnable_load_avg);
SEQ_printf(m, " .%-30s: %ld\n", "blocked_load_avg",
cfs_rq->blocked_load_avg);
+ SEQ_printf(m, " .%-30s: %ld\n", "utilization_load_avg",
+ cfs_rq->utilization_load_avg);
#ifdef CONFIG_FAIR_GROUP_SCHED
SEQ_printf(m, " .%-30s: %ld\n", "tg_load_contrib",
cfs_rq->tg_load_contrib);
@@ -261,6 +265,12 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
#undef P
}
+void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
+{
+ SEQ_printf(m, "\ndl_rq[%d]:\n", cpu);
+ SEQ_printf(m, " .%-30s: %ld\n", "dl_nr_running", dl_rq->dl_nr_running);
+}
+
extern __read_mostly int sched_clock_running;
static void print_cpu(struct seq_file *m, int cpu)
@@ -329,6 +339,7 @@ do { \
spin_lock_irqsave(&sched_debug_lock, flags);
print_cfs_stats(m, cpu);
print_rt_stats(m, cpu);
+ print_dl_stats(m, cpu);
print_rq(m, rq, cpu);
spin_unlock_irqrestore(&sched_debug_lock, flags);
@@ -528,8 +539,8 @@ static void sched_show_numa(struct task_struct *p, struct seq_file *m)
unsigned long nr_faults = -1;
int cpu_current, home_node;
- if (p->numa_faults_memory)
- nr_faults = p->numa_faults_memory[2*node + i];
+ if (p->numa_faults)
+ nr_faults = p->numa_faults[2*node + i];
cpu_current = !i ? (task_node(p) == node) :
(pol && node_isset(node, pol->v.nodes));
@@ -628,8 +639,10 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
P(se.load.weight);
#ifdef CONFIG_SMP
P(se.avg.runnable_avg_sum);
- P(se.avg.runnable_avg_period);
+ P(se.avg.running_avg_sum);
+ P(se.avg.avg_period);
P(se.avg.load_avg_contrib);
+ P(se.avg.utilization_avg_contrib);
P(se.avg.decay_count);
#endif
P(policy);
diff --git a/kernel/sched/energy_model.c b/kernel/sched/energy_model.c
new file mode 100644
index 000000000000..1599fe5dbbb1
--- /dev/null
+++ b/kernel/sched/energy_model.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright (C) 2014 Michael Turquette <mturquette@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+
+#include "sched.h"
+
+#define THROTTLE_MSEC 50
+#define UP_THRESHOLD 80
+#define DOWN_THRESHOLD 20
+
+/**
+ * em_data - per-policy data used by energy_mode
+ * @throttle: bail if current time is less than than ktime_throttle.
+ * Derived from THROTTLE_MSEC
+ * @up_threshold: table of normalized capacity states to determine if cpu
+ * should run faster. Derived from UP_THRESHOLD
+ * @down_threshold: table of normalized capacity states to determine if cpu
+ * should run slower. Derived from DOWN_THRESHOLD
+ *
+ * struct em_data is the per-policy energy_model-specific data structure. A
+ * per-policy instance of it is created when the energy_model governor receives
+ * the CPUFREQ_GOV_START condition and a pointer to it exists in the gov_data
+ * member of struct cpufreq_policy.
+ *
+ * Readers of this data must call down_read(policy->rwsem). Writers must
+ * call down_write(policy->rwsem).
+ */
+struct em_data {
+ /* per-policy throttling */
+ ktime_t throttle;
+ unsigned int *up_threshold;
+ unsigned int *down_threshold;
+ struct task_struct *task;
+ atomic_long_t target_freq;
+ atomic_t need_wake_task;
+};
+
+/*
+ * we pass in struct cpufreq_policy. This is safe because changing out the
+ * policy requires a call to __cpufreq_governor(policy, CPUFREQ_GOV_STOP),
+ * which tears all of the data structures down and __cpufreq_governor(policy,
+ * CPUFREQ_GOV_START) will do a full rebuild, including this kthread with the
+ * new policy pointer
+ */
+static int energy_model_thread(void *data)
+{
+ struct sched_param param;
+ struct cpufreq_policy *policy;
+ struct em_data *em;
+ int ret;
+
+ policy = (struct cpufreq_policy *) data;
+ if (!policy) {
+ pr_warn("%s: missing policy\n", __func__);
+ do_exit(-EINVAL);
+ }
+
+ em = policy->gov_data;
+ if (!em) {
+ pr_warn("%s: missing governor data\n", __func__);
+ do_exit(-EINVAL);
+ }
+
+ param.sched_priority = 0;
+ sched_setscheduler(current, SCHED_FIFO, &param);
+
+
+ do {
+ down_write(&policy->rwsem);
+ if (!atomic_read(&em->need_wake_task)) {
+ up_write(&policy->rwsem);
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ continue;
+ }
+
+ ret = __cpufreq_driver_target(policy, atomic_read(&em->target_freq),
+ CPUFREQ_RELATION_H);
+ if (ret)
+ pr_debug("%s: __cpufreq_driver_target returned %d\n",
+ __func__, ret);
+
+ em->throttle = ktime_get();
+ atomic_set(&em->need_wake_task, 0);
+ up_write(&policy->rwsem);
+ } while (!kthread_should_stop());
+
+ do_exit(0);
+}
+
+static void em_wake_up_process(struct task_struct *task)
+{
+ /* this is null during early boot */
+ if (IS_ERR_OR_NULL(task)) {
+ return;
+ }
+
+ wake_up_process(task);
+}
+
+void arch_scale_cpu_freq(void)
+{
+ struct cpufreq_policy *policy;
+ struct em_data *em;
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ policy = cpufreq_cpu_get(cpu);
+ if (IS_ERR_OR_NULL(policy))
+ continue;
+
+ em = policy->gov_data;
+ if (!em)
+ continue;
+
+ /*
+ * FIXME replace the atomic stuff by holding write-locks
+ * in arch_eval_cpu_freq?
+ */
+ if (atomic_read(&em->need_wake_task)) {
+ em_wake_up_process(em->task);
+ }
+
+ cpufreq_cpu_put(policy);
+ }
+}
+
+/**
+ * arch_eval_cpu_freq - scale cpu frequency based on CFS utilization
+ * @update_cpus: mask of CPUs with updated utilization and capacity
+ *
+ * Declared and weakly defined in kernel/sched/fair.c This definition overrides
+ * the default. In the case of CONFIG_FAIR_GROUP_SCHED, update_cpus may
+ * contains cpus that are not in the same policy. Otherwise update_cpus will be
+ * a single cpu.
+ *
+ * Holds read lock for policy->rw_sem.
+ *
+ * FIXME weak arch function means that only one definition of this function can
+ * be linked. How to support multiple energy model policies?
+ */
+void arch_eval_cpu_freq(struct cpumask *update_cpus)
+{
+ struct cpufreq_policy *policy;
+ struct em_data *em;
+ int index;
+ unsigned int cpu, tmp;
+ unsigned long percent_util = 0, max_util = 0, cap = 0, util = 0;
+
+ /*
+ * In the case of CONFIG_FAIR_GROUP_SCHED, policy->cpus may be a subset
+ * of update_cpus. In such case take the first cpu in update_cpus, get
+ * its policy and try to scale the affects cpus. Then we clear the
+ * corresponding bits from update_cpus and try again. If a policy does
+ * not exist for a cpu then we remove that bit as well, preventing an
+ * infinite loop.
+ */
+ while (!cpumask_empty(update_cpus)) {
+ percent_util = 0;
+ max_util = 0;
+ cap = 0;
+ util = 0;
+
+ cpu = cpumask_first(update_cpus);
+ policy = cpufreq_cpu_get(cpu);
+ if (IS_ERR_OR_NULL(policy)) {
+ cpumask_clear_cpu(cpu, update_cpus);
+ continue;
+ }
+
+ if (!policy->gov_data)
+ return;
+
+ em = policy->gov_data;
+
+ if (ktime_before(ktime_get(), em->throttle)) {
+ trace_printk("THROTTLED");
+ goto bail;
+ }
+
+ /*
+ * try scaling cpus
+ *
+ * algorithm assumptions & description:
+ * all cpus in a policy run at the same rate/capacity.
+ * choose frequency target based on most utilized cpu.
+ * do not care about aggregating cpu utilization.
+ * do not track any historical trends beyond utilization
+ * if max_util > 80% of current capacity,
+ * go to max capacity
+ * if max_util < 20% of current capacity,
+ * go to the next lowest capacity
+ * otherwise, stay at the same capacity state
+ */
+ for_each_cpu(tmp, policy->cpus) {
+ util = get_cpu_usage(cpu);
+ if (util > max_util)
+ max_util = util;
+ }
+
+ cap = capacity_of(cpu);
+ if (!cap) {
+ goto bail;
+ }
+
+ index = cpufreq_frequency_table_get_index(policy, policy->cur);
+ if (max_util > em->up_threshold[index]) {
+ /* write em->target_freq with read lock held */
+ atomic_long_set(&em->target_freq, policy->max);
+ /*
+ * FIXME this is gross. convert arch_eval_cpu_freq to
+ * hold the write lock?
+ */
+ atomic_set(&em->need_wake_task, 1);
+ } else if (max_util < em->down_threshold[index]) {
+ /* write em->target_freq with read lock held */
+ atomic_long_set(&em->target_freq, policy->cur - 1);
+ /*
+ * FIXME this is gross. convert arch_eval_cpu_freq to
+ * hold the write lock?
+ */
+ atomic_set(&em->need_wake_task, 1);
+ }
+
+bail:
+ /* remove policy->cpus fromm update_cpus */
+ cpumask_andnot(update_cpus, update_cpus, policy->cpus);
+ cpufreq_cpu_put(policy);
+ }
+
+ return;
+}
+
+static void em_start(struct cpufreq_policy *policy)
+{
+ int index = 0, count = 0;
+ unsigned int capacity;
+ struct em_data *em;
+ struct cpufreq_frequency_table *pos;
+
+ /* prepare per-policy private data */
+ em = kzalloc(sizeof(*em), GFP_KERNEL);
+ if (!em) {
+ pr_debug("%s: failed to allocate private data\n", __func__);
+ return;
+ }
+
+ policy->gov_data = em;
+
+ /* how many entries in the frequency table? */
+ cpufreq_for_each_entry(pos, policy->freq_table)
+ count++;
+
+ /* pre-compute thresholds */
+ em->up_threshold = kcalloc(count, sizeof(unsigned int), GFP_KERNEL);
+ em->down_threshold = kcalloc(count, sizeof(unsigned int), GFP_KERNEL);
+
+ cpufreq_for_each_entry(pos, policy->freq_table) {
+ /* FIXME capacity below is not scaled for uarch */
+ capacity = pos->frequency * SCHED_CAPACITY_SCALE / policy->max;
+ em->up_threshold[index] = capacity * UP_THRESHOLD / 100;
+ em->down_threshold[index] = capacity * DOWN_THRESHOLD / 100;
+ pr_debug("%s: cpu = %u index = %d capacity = %u up = %u down = %u\n",
+ __func__, cpumask_first(policy->cpus), index,
+ capacity, em->up_threshold[index],
+ em->down_threshold[index]);
+ index++;
+ }
+
+ /* init per-policy kthread */
+ em->task = kthread_create(energy_model_thread, policy, "kenergy_model_task");
+ if (IS_ERR_OR_NULL(em->task))
+ pr_err("%s: failed to create kenergy_model_task thread\n", __func__);
+}
+
+
+static void em_stop(struct cpufreq_policy *policy)
+{
+ struct em_data *em;
+
+ em = policy->gov_data;
+
+ kthread_stop(em->task);
+
+ /* replace with devm counterparts */
+ kfree(em->up_threshold);
+ kfree(em->down_threshold);
+ kfree(em);
+}
+
+static int energy_model_setup(struct cpufreq_policy *policy, unsigned int event)
+{
+ switch (event) {
+ case CPUFREQ_GOV_START:
+ /* Start managing the frequency */
+ em_start(policy);
+ return 0;
+
+ case CPUFREQ_GOV_STOP:
+ em_stop(policy);
+ return 0;
+
+ case CPUFREQ_GOV_LIMITS: /* unused */
+ case CPUFREQ_GOV_POLICY_INIT: /* unused */
+ case CPUFREQ_GOV_POLICY_EXIT: /* unused */
+ break;
+ }
+ return 0;
+}
+
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ENERGY_MODEL
+static
+#endif
+struct cpufreq_governor cpufreq_gov_energy_model = {
+ .name = "energy_model",
+ .governor = energy_model_setup,
+ .owner = THIS_MODULE,
+};
+
+static int __init energy_model_init(void)
+{
+ return cpufreq_register_governor(&cpufreq_gov_energy_model);
+}
+
+static void __exit energy_model_exit(void)
+{
+ cpufreq_unregister_governor(&cpufreq_gov_energy_model);
+}
+
+/* Try to make this the default governor */
+fs_initcall(energy_model_init);
+
+MODULE_LICENSE("GPL");
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5cc44f21fe5a..5f3056215e41 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -674,6 +674,7 @@ static int select_idle_sibling(struct task_struct *p, int cpu);
static unsigned long task_h_load(struct task_struct *p);
static inline void __update_task_entity_contrib(struct sched_entity *se);
+static inline void __update_task_entity_utilization(struct sched_entity *se);
/* Give new task start runnable values to heavy its load in infant time */
void init_task_runnable_average(struct task_struct *p)
@@ -682,9 +683,10 @@ void init_task_runnable_average(struct task_struct *p)
p->se.avg.decay_count = 0;
slice = sched_slice(task_cfs_rq(p), &p->se) >> 10;
- p->se.avg.runnable_avg_sum = slice;
- p->se.avg.runnable_avg_period = slice;
+ p->se.avg.runnable_avg_sum = p->se.avg.running_avg_sum = slice;
+ p->se.avg.avg_period = slice;
__update_task_entity_contrib(&p->se);
+ __update_task_entity_utilization(&p->se);
}
#else
void init_task_runnable_average(struct task_struct *p)
@@ -832,11 +834,12 @@ static unsigned int task_nr_scan_windows(struct task_struct *p)
static unsigned int task_scan_min(struct task_struct *p)
{
+ unsigned int scan_size = ACCESS_ONCE(sysctl_numa_balancing_scan_size);
unsigned int scan, floor;
unsigned int windows = 1;
- if (sysctl_numa_balancing_scan_size < MAX_SCAN_WINDOW)
- windows = MAX_SCAN_WINDOW / sysctl_numa_balancing_scan_size;
+ if (scan_size < MAX_SCAN_WINDOW)
+ windows = MAX_SCAN_WINDOW / scan_size;
floor = 1000 / windows;
scan = sysctl_numa_balancing_scan_period_min / task_nr_scan_windows(p);
@@ -899,18 +902,24 @@ pid_t task_numa_group_id(struct task_struct *p)
return p->numa_group ? p->numa_group->gid : 0;
}
-static inline int task_faults_idx(int nid, int priv)
+/*
+ * The averaged statistics, shared & private, memory & cpu,
+ * occupy the first half of the array. The second half of the
+ * array is for current counters, which are averaged into the
+ * first set by task_numa_placement.
+ */
+static inline int task_faults_idx(enum numa_faults_stats s, int nid, int priv)
{
- return NR_NUMA_HINT_FAULT_TYPES * nid + priv;
+ return NR_NUMA_HINT_FAULT_TYPES * (s * nr_node_ids + nid) + priv;
}
static inline unsigned long task_faults(struct task_struct *p, int nid)
{
- if (!p->numa_faults_memory)
+ if (!p->numa_faults)
return 0;
- return p->numa_faults_memory[task_faults_idx(nid, 0)] +
- p->numa_faults_memory[task_faults_idx(nid, 1)];
+ return p->numa_faults[task_faults_idx(NUMA_MEM, nid, 0)] +
+ p->numa_faults[task_faults_idx(NUMA_MEM, nid, 1)];
}
static inline unsigned long group_faults(struct task_struct *p, int nid)
@@ -918,14 +927,79 @@ static inline unsigned long group_faults(struct task_struct *p, int nid)
if (!p->numa_group)
return 0;
- return p->numa_group->faults[task_faults_idx(nid, 0)] +
- p->numa_group->faults[task_faults_idx(nid, 1)];
+ return p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 0)] +
+ p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 1)];
}
static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
{
- return group->faults_cpu[task_faults_idx(nid, 0)] +
- group->faults_cpu[task_faults_idx(nid, 1)];
+ return group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 0)] +
+ group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)];
+}
+
+/* Handle placement on systems where not all nodes are directly connected. */
+static unsigned long score_nearby_nodes(struct task_struct *p, int nid,
+ int maxdist, bool task)
+{
+ unsigned long score = 0;
+ int node;
+
+ /*
+ * All nodes are directly connected, and the same distance
+ * from each other. No need for fancy placement algorithms.
+ */
+ if (sched_numa_topology_type == NUMA_DIRECT)
+ return 0;
+
+ /*
+ * This code is called for each node, introducing N^2 complexity,
+ * which should be ok given the number of nodes rarely exceeds 8.
+ */
+ for_each_online_node(node) {
+ unsigned long faults;
+ int dist = node_distance(nid, node);
+
+ /*
+ * The furthest away nodes in the system are not interesting
+ * for placement; nid was already counted.
+ */
+ if (dist == sched_max_numa_distance || node == nid)
+ continue;
+
+ /*
+ * On systems with a backplane NUMA topology, compare groups
+ * of nodes, and move tasks towards the group with the most
+ * memory accesses. When comparing two nodes at distance
+ * "hoplimit", only nodes closer by than "hoplimit" are part
+ * of each group. Skip other nodes.
+ */
+ if (sched_numa_topology_type == NUMA_BACKPLANE &&
+ dist > maxdist)
+ continue;
+
+ /* Add up the faults from nearby nodes. */
+ if (task)
+ faults = task_faults(p, node);
+ else
+ faults = group_faults(p, node);
+
+ /*
+ * On systems with a glueless mesh NUMA topology, there are
+ * no fixed "groups of nodes". Instead, nodes that are not
+ * directly connected bounce traffic through intermediate
+ * nodes; a numa_group can occupy any set of nodes.
+ * The further away a node is, the less the faults count.
+ * This seems to result in good task placement.
+ */
+ if (sched_numa_topology_type == NUMA_GLUELESS_MESH) {
+ faults *= (sched_max_numa_distance - dist);
+ faults /= (sched_max_numa_distance - LOCAL_DISTANCE);
+ }
+
+ score += faults;
+ }
+
+ return score;
}
/*
@@ -934,11 +1008,12 @@ static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
* larger multiplier, in order to group tasks together that are almost
* evenly spread out between numa nodes.
*/
-static inline unsigned long task_weight(struct task_struct *p, int nid)
+static inline unsigned long task_weight(struct task_struct *p, int nid,
+ int dist)
{
- unsigned long total_faults;
+ unsigned long faults, total_faults;
- if (!p->numa_faults_memory)
+ if (!p->numa_faults)
return 0;
total_faults = p->total_numa_faults;
@@ -946,15 +1021,29 @@ static inline unsigned long task_weight(struct task_struct *p, int nid)
if (!total_faults)
return 0;
- return 1000 * task_faults(p, nid) / total_faults;
+ faults = task_faults(p, nid);
+ faults += score_nearby_nodes(p, nid, dist, true);
+
+ return 1000 * faults / total_faults;
}
-static inline unsigned long group_weight(struct task_struct *p, int nid)
+static inline unsigned long group_weight(struct task_struct *p, int nid,
+ int dist)
{
- if (!p->numa_group || !p->numa_group->total_faults)
+ unsigned long faults, total_faults;
+
+ if (!p->numa_group)
return 0;
- return 1000 * group_faults(p, nid) / p->numa_group->total_faults;
+ total_faults = p->numa_group->total_faults;
+
+ if (!total_faults)
+ return 0;
+
+ faults = group_faults(p, nid);
+ faults += score_nearby_nodes(p, nid, dist, false);
+
+ return 1000 * faults / total_faults;
}
bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
@@ -1023,7 +1112,6 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
static unsigned long weighted_cpuload(const int cpu);
static unsigned long source_load(int cpu, int type);
static unsigned long target_load(int cpu, int type);
-static unsigned long capacity_of(int cpu);
static long effective_load(struct task_group *tg, int cpu, long wl, long wg);
/* Cached statistics for all CPUs within a node */
@@ -1087,6 +1175,7 @@ struct task_numa_env {
struct numa_stats src_stats, dst_stats;
int imbalance_pct;
+ int dist;
struct task_struct *best_task;
long best_imp;
@@ -1166,11 +1255,22 @@ static void task_numa_compare(struct task_numa_env *env,
long load;
long imp = env->p->numa_group ? groupimp : taskimp;
long moveimp = imp;
+ int dist = env->dist;
rcu_read_lock();
- cur = ACCESS_ONCE(dst_rq->curr);
- if (cur->pid == 0) /* idle */
+
+ raw_spin_lock_irq(&dst_rq->lock);
+ cur = dst_rq->curr;
+ /*
+ * No need to move the exiting task, and this ensures that ->curr
+ * wasn't reaped and thus get_task_struct() in task_numa_assign()
+ * is safe under RCU read lock.
+ * Note that rcu_read_lock() itself can't protect from the final
+ * put_task_struct() after the last schedule().
+ */
+ if ((cur->flags & PF_EXITING) || is_idle_task(cur))
cur = NULL;
+ raw_spin_unlock_irq(&dst_rq->lock);
/*
* "imp" is the fault differential for the source task between the
@@ -1189,8 +1289,8 @@ static void task_numa_compare(struct task_numa_env *env,
* in any group then look only at task weights.
*/
if (cur->numa_group == env->p->numa_group) {
- imp = taskimp + task_weight(cur, env->src_nid) -
- task_weight(cur, env->dst_nid);
+ imp = taskimp + task_weight(cur, env->src_nid, dist) -
+ task_weight(cur, env->dst_nid, dist);
/*
* Add some hysteresis to prevent swapping the
* tasks within a group over tiny differences.
@@ -1204,11 +1304,11 @@ static void task_numa_compare(struct task_numa_env *env,
* instead.
*/
if (cur->numa_group)
- imp += group_weight(cur, env->src_nid) -
- group_weight(cur, env->dst_nid);
+ imp += group_weight(cur, env->src_nid, dist) -
+ group_weight(cur, env->dst_nid, dist);
else
- imp += task_weight(cur, env->src_nid) -
- task_weight(cur, env->dst_nid);
+ imp += task_weight(cur, env->src_nid, dist) -
+ task_weight(cur, env->dst_nid, dist);
}
}
@@ -1307,7 +1407,7 @@ static int task_numa_migrate(struct task_struct *p)
};
struct sched_domain *sd;
unsigned long taskweight, groupweight;
- int nid, ret;
+ int nid, ret, dist;
long taskimp, groupimp;
/*
@@ -1335,29 +1435,45 @@ static int task_numa_migrate(struct task_struct *p)
return -EINVAL;
}
- taskweight = task_weight(p, env.src_nid);
- groupweight = group_weight(p, env.src_nid);
- update_numa_stats(&env.src_stats, env.src_nid);
env.dst_nid = p->numa_preferred_nid;
- taskimp = task_weight(p, env.dst_nid) - taskweight;
- groupimp = group_weight(p, env.dst_nid) - groupweight;
+ dist = env.dist = node_distance(env.src_nid, env.dst_nid);
+ taskweight = task_weight(p, env.src_nid, dist);
+ groupweight = group_weight(p, env.src_nid, dist);
+ update_numa_stats(&env.src_stats, env.src_nid);
+ taskimp = task_weight(p, env.dst_nid, dist) - taskweight;
+ groupimp = group_weight(p, env.dst_nid, dist) - groupweight;
update_numa_stats(&env.dst_stats, env.dst_nid);
/* Try to find a spot on the preferred nid. */
task_numa_find_cpu(&env, taskimp, groupimp);
- /* No space available on the preferred nid. Look elsewhere. */
- if (env.best_cpu == -1) {
+ /*
+ * Look at other nodes in these cases:
+ * - there is no space available on the preferred_nid
+ * - the task is part of a numa_group that is interleaved across
+ * multiple NUMA nodes; in order to better consolidate the group,
+ * we need to check other locations.
+ */
+ if (env.best_cpu == -1 || (p->numa_group &&
+ nodes_weight(p->numa_group->active_nodes) > 1)) {
for_each_online_node(nid) {
if (nid == env.src_nid || nid == p->numa_preferred_nid)
continue;
+ dist = node_distance(env.src_nid, env.dst_nid);
+ if (sched_numa_topology_type == NUMA_BACKPLANE &&
+ dist != env.dist) {
+ taskweight = task_weight(p, env.src_nid, dist);
+ groupweight = group_weight(p, env.src_nid, dist);
+ }
+
/* Only consider nodes where both task and groups benefit */
- taskimp = task_weight(p, nid) - taskweight;
- groupimp = group_weight(p, nid) - groupweight;
+ taskimp = task_weight(p, nid, dist) - taskweight;
+ groupimp = group_weight(p, nid, dist) - groupweight;
if (taskimp < 0 && groupimp < 0)
continue;
+ env.dist = dist;
env.dst_nid = nid;
update_numa_stats(&env.dst_stats, env.dst_nid);
task_numa_find_cpu(&env, taskimp, groupimp);
@@ -1412,7 +1528,7 @@ static void numa_migrate_preferred(struct task_struct *p)
unsigned long interval = HZ;
/* This task has no NUMA fault statistics yet */
- if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults_memory))
+ if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
return;
/* Periodically retry migrating the task to the preferred node */
@@ -1524,7 +1640,7 @@ static void update_task_scan_period(struct task_struct *p,
* scanning faster if shared accesses dominate as it may
* simply bounce migrations uselessly
*/
- ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared));
+ ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared + 1));
diff = (diff * ratio) / NUMA_PERIOD_SLOTS;
}
@@ -1552,7 +1668,7 @@ static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period)
*period = now - p->last_task_numa_placement;
} else {
delta = p->se.avg.runnable_avg_sum;
- *period = p->se.avg.runnable_avg_period;
+ *period = p->se.avg.avg_period;
}
p->last_sum_exec_runtime = runtime;
@@ -1561,6 +1677,92 @@ static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period)
return delta;
}
+/*
+ * Determine the preferred nid for a task in a numa_group. This needs to
+ * be done in a way that produces consistent results with group_weight,
+ * otherwise workloads might not converge.
+ */
+static int preferred_group_nid(struct task_struct *p, int nid)
+{
+ nodemask_t nodes;
+ int dist;
+
+ /* Direct connections between all NUMA nodes. */
+ if (sched_numa_topology_type == NUMA_DIRECT)
+ return nid;
+
+ /*
+ * On a system with glueless mesh NUMA topology, group_weight
+ * scores nodes according to the number of NUMA hinting faults on
+ * both the node itself, and on nearby nodes.
+ */
+ if (sched_numa_topology_type == NUMA_GLUELESS_MESH) {
+ unsigned long score, max_score = 0;
+ int node, max_node = nid;
+
+ dist = sched_max_numa_distance;
+
+ for_each_online_node(node) {
+ score = group_weight(p, node, dist);
+ if (score > max_score) {
+ max_score = score;
+ max_node = node;
+ }
+ }
+ return max_node;
+ }
+
+ /*
+ * Finding the preferred nid in a system with NUMA backplane
+ * interconnect topology is more involved. The goal is to locate
+ * tasks from numa_groups near each other in the system, and
+ * untangle workloads from different sides of the system. This requires
+ * searching down the hierarchy of node groups, recursively searching
+ * inside the highest scoring group of nodes. The nodemask tricks
+ * keep the complexity of the search down.
+ */
+ nodes = node_online_map;
+ for (dist = sched_max_numa_distance; dist > LOCAL_DISTANCE; dist--) {
+ unsigned long max_faults = 0;
+ nodemask_t max_group;
+ int a, b;
+
+ /* Are there nodes at this distance from each other? */
+ if (!find_numa_distance(dist))
+ continue;
+
+ for_each_node_mask(a, nodes) {
+ unsigned long faults = 0;
+ nodemask_t this_group;
+ nodes_clear(this_group);
+
+ /* Sum group's NUMA faults; includes a==b case. */
+ for_each_node_mask(b, nodes) {
+ if (node_distance(a, b) < dist) {
+ faults += group_faults(p, b);
+ node_set(b, this_group);
+ node_clear(b, nodes);
+ }
+ }
+
+ /* Remember the top group. */
+ if (faults > max_faults) {
+ max_faults = faults;
+ max_group = this_group;
+ /*
+ * subtle: at the smallest distance there is
+ * just one node left in each "group", the
+ * winner is the preferred nid.
+ */
+ nid = a;
+ }
+ }
+ /* Next round, evaluate the nodes within max_group. */
+ nodes = max_group;
+ }
+ return nid;
+}
+
static void task_numa_placement(struct task_struct *p)
{
int seq, nid, max_nid = -1, max_group_nid = -1;
@@ -1588,18 +1790,23 @@ static void task_numa_placement(struct task_struct *p)
/* Find the node with the highest number of faults */
for_each_online_node(nid) {
+ /* Keep track of the offsets in numa_faults array */
+ int mem_idx, membuf_idx, cpu_idx, cpubuf_idx;
unsigned long faults = 0, group_faults = 0;
- int priv, i;
+ int priv;
for (priv = 0; priv < NR_NUMA_HINT_FAULT_TYPES; priv++) {
long diff, f_diff, f_weight;
- i = task_faults_idx(nid, priv);
+ mem_idx = task_faults_idx(NUMA_MEM, nid, priv);
+ membuf_idx = task_faults_idx(NUMA_MEMBUF, nid, priv);
+ cpu_idx = task_faults_idx(NUMA_CPU, nid, priv);
+ cpubuf_idx = task_faults_idx(NUMA_CPUBUF, nid, priv);
/* Decay existing window, copy faults since last scan */
- diff = p->numa_faults_buffer_memory[i] - p->numa_faults_memory[i] / 2;
- fault_types[priv] += p->numa_faults_buffer_memory[i];
- p->numa_faults_buffer_memory[i] = 0;
+ diff = p->numa_faults[membuf_idx] - p->numa_faults[mem_idx] / 2;
+ fault_types[priv] += p->numa_faults[membuf_idx];
+ p->numa_faults[membuf_idx] = 0;
/*
* Normalize the faults_from, so all tasks in a group
@@ -1609,21 +1816,27 @@ static void task_numa_placement(struct task_struct *p)
* faults are less important.
*/
f_weight = div64_u64(runtime << 16, period + 1);
- f_weight = (f_weight * p->numa_faults_buffer_cpu[i]) /
+ f_weight = (f_weight * p->numa_faults[cpubuf_idx]) /
(total_faults + 1);
- f_diff = f_weight - p->numa_faults_cpu[i] / 2;
- p->numa_faults_buffer_cpu[i] = 0;
+ f_diff = f_weight - p->numa_faults[cpu_idx] / 2;
+ p->numa_faults[cpubuf_idx] = 0;
- p->numa_faults_memory[i] += diff;
- p->numa_faults_cpu[i] += f_diff;
- faults += p->numa_faults_memory[i];
+ p->numa_faults[mem_idx] += diff;
+ p->numa_faults[cpu_idx] += f_diff;
+ faults += p->numa_faults[mem_idx];
p->total_numa_faults += diff;
if (p->numa_group) {
- /* safe because we can only change our own group */
- p->numa_group->faults[i] += diff;
- p->numa_group->faults_cpu[i] += f_diff;
+ /*
+ * safe because we can only change our own group
+ *
+ * mem_idx represents the offset for a given
+ * nid and priv in a specific region because it
+ * is at the beginning of the numa_faults array.
+ */
+ p->numa_group->faults[mem_idx] += diff;
+ p->numa_group->faults_cpu[mem_idx] += f_diff;
p->numa_group->total_faults += diff;
- group_faults += p->numa_group->faults[i];
+ group_faults += p->numa_group->faults[mem_idx];
}
}
@@ -1643,7 +1856,7 @@ static void task_numa_placement(struct task_struct *p)
if (p->numa_group) {
update_numa_active_node_mask(p->numa_group);
spin_unlock_irq(group_lock);
- max_nid = max_group_nid;
+ max_nid = preferred_group_nid(p, max_group_nid);
}
if (max_faults) {
@@ -1695,7 +1908,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
node_set(task_node(current), grp->active_nodes);
for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
- grp->faults[i] = p->numa_faults_memory[i];
+ grp->faults[i] = p->numa_faults[i];
grp->total_faults = p->total_numa_faults;
@@ -1754,8 +1967,8 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
double_lock_irq(&my_grp->lock, &grp->lock);
for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) {
- my_grp->faults[i] -= p->numa_faults_memory[i];
- grp->faults[i] += p->numa_faults_memory[i];
+ my_grp->faults[i] -= p->numa_faults[i];
+ grp->faults[i] += p->numa_faults[i];
}
my_grp->total_faults -= p->total_numa_faults;
grp->total_faults += p->total_numa_faults;
@@ -1780,14 +1993,14 @@ no_join:
void task_numa_free(struct task_struct *p)
{
struct numa_group *grp = p->numa_group;
- void *numa_faults = p->numa_faults_memory;
+ void *numa_faults = p->numa_faults;
unsigned long flags;
int i;
if (grp) {
spin_lock_irqsave(&grp->lock, flags);
for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
- grp->faults[i] -= p->numa_faults_memory[i];
+ grp->faults[i] -= p->numa_faults[i];
grp->total_faults -= p->total_numa_faults;
list_del(&p->numa_entry);
@@ -1797,10 +2010,7 @@ void task_numa_free(struct task_struct *p)
put_numa_group(grp);
}
- p->numa_faults_memory = NULL;
- p->numa_faults_buffer_memory = NULL;
- p->numa_faults_cpu= NULL;
- p->numa_faults_buffer_cpu = NULL;
+ p->numa_faults = NULL;
kfree(numa_faults);
}
@@ -1823,24 +2033,14 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
return;
/* Allocate buffer to track faults on a per-node basis */
- if (unlikely(!p->numa_faults_memory)) {
- int size = sizeof(*p->numa_faults_memory) *
+ if (unlikely(!p->numa_faults)) {
+ int size = sizeof(*p->numa_faults) *
NR_NUMA_HINT_FAULT_BUCKETS * nr_node_ids;
- p->numa_faults_memory = kzalloc(size, GFP_KERNEL|__GFP_NOWARN);
- if (!p->numa_faults_memory)
+ p->numa_faults = kzalloc(size, GFP_KERNEL|__GFP_NOWARN);
+ if (!p->numa_faults)
return;
- BUG_ON(p->numa_faults_buffer_memory);
- /*
- * The averaged statistics, shared & private, memory & cpu,
- * occupy the first half of the array. The second half of the
- * array is for current counters, which are averaged into the
- * first set by task_numa_placement.
- */
- p->numa_faults_cpu = p->numa_faults_memory + (2 * nr_node_ids);
- p->numa_faults_buffer_memory = p->numa_faults_memory + (4 * nr_node_ids);
- p->numa_faults_buffer_cpu = p->numa_faults_memory + (6 * nr_node_ids);
p->total_numa_faults = 0;
memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
}
@@ -1880,8 +2080,8 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
if (migrated)
p->numa_pages_migrated += pages;
- p->numa_faults_buffer_memory[task_faults_idx(mem_node, priv)] += pages;
- p->numa_faults_buffer_cpu[task_faults_idx(cpu_node, priv)] += pages;
+ p->numa_faults[task_faults_idx(NUMA_MEMBUF, mem_node, priv)] += pages;
+ p->numa_faults[task_faults_idx(NUMA_CPUBUF, cpu_node, priv)] += pages;
p->numa_faults_locality[local] += pages;
}
@@ -2064,6 +2264,11 @@ static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
}
#endif /* CONFIG_NUMA_BALANCING */
+#ifdef CONFIG_SMP
+unsigned long capacity_of(int cpu);
+//unsigned long usage_util_of(int cpu);
+#endif /* CONFIG_SMP */
+
static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
@@ -2268,6 +2473,10 @@ static u32 __compute_runnable_contrib(u64 n)
return contrib + runnable_avg_yN_sum[n];
}
+unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu);
+void arch_eval_cpu_freq(struct cpumask *cpus);
+void arch_scale_cpu_freq(void);
+
/*
* We can represent the historical contribution to runnable average as the
* coefficients of a geometric series. To do this we sub-divide our runnable
@@ -2296,13 +2505,15 @@ static u32 __compute_runnable_contrib(u64 n)
* load_avg = u_0` + y*(u_0 + u_1*y + u_2*y^2 + ... )
* = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}]
*/
-static __always_inline int __update_entity_runnable_avg(u64 now,
+static __always_inline int __update_entity_runnable_avg(u64 now, int cpu,
struct sched_avg *sa,
- int runnable)
+ int runnable,
+ int running)
{
u64 delta, periods;
u32 runnable_contrib;
int delta_w, decayed = 0;
+ unsigned long scale_freq = arch_scale_freq_capacity(NULL, cpu);
delta = now - sa->last_runnable_update;
/*
@@ -2324,7 +2535,7 @@ static __always_inline int __update_entity_runnable_avg(u64 now,
sa->last_runnable_update = now;
/* delta_w is the amount already accumulated against our next period */
- delta_w = sa->runnable_avg_period % 1024;
+ delta_w = sa->avg_period % 1024;
if (delta + delta_w >= 1024) {
/* period roll-over */
decayed = 1;
@@ -2337,7 +2548,10 @@ static __always_inline int __update_entity_runnable_avg(u64 now,
delta_w = 1024 - delta_w;
if (runnable)
sa->runnable_avg_sum += delta_w;
- sa->runnable_avg_period += delta_w;
+ if (running)
+ sa->running_avg_sum += delta_w * scale_freq
+ >> SCHED_CAPACITY_SHIFT;
+ sa->avg_period += delta_w;
delta -= delta_w;
@@ -2347,20 +2561,28 @@ static __always_inline int __update_entity_runnable_avg(u64 now,
sa->runnable_avg_sum = decay_load(sa->runnable_avg_sum,
periods + 1);
- sa->runnable_avg_period = decay_load(sa->runnable_avg_period,
+ sa->running_avg_sum = decay_load(sa->running_avg_sum,
+ periods + 1);
+ sa->avg_period = decay_load(sa->avg_period,
periods + 1);
/* Efficiently calculate \sum (1..n_period) 1024*y^i */
runnable_contrib = __compute_runnable_contrib(periods);
if (runnable)
sa->runnable_avg_sum += runnable_contrib;
- sa->runnable_avg_period += runnable_contrib;
+ if (running)
+ sa->running_avg_sum += runnable_contrib * scale_freq
+ >> SCHED_CAPACITY_SHIFT;
+ sa->avg_period += runnable_contrib;
}
/* Remainder of delta accrued against u_0` */
if (runnable)
sa->runnable_avg_sum += delta;
- sa->runnable_avg_period += delta;
+ if (running)
+ sa->running_avg_sum += delta * scale_freq
+ >> SCHED_CAPACITY_SHIFT;
+ sa->avg_period += delta;
return decayed;
}
@@ -2376,6 +2598,8 @@ static inline u64 __synchronize_entity_decay(struct sched_entity *se)
return 0;
se->avg.load_avg_contrib = decay_load(se->avg.load_avg_contrib, decays);
+ se->avg.utilization_avg_contrib =
+ decay_load(se->avg.utilization_avg_contrib, decays);
se->avg.decay_count = 0;
return decays;
@@ -2412,7 +2636,7 @@ static inline void __update_tg_runnable_avg(struct sched_avg *sa,
/* The fraction of a cpu used by this cfs_rq */
contrib = div_u64((u64)sa->runnable_avg_sum << NICE_0_SHIFT,
- sa->runnable_avg_period + 1);
+ sa->avg_period + 1);
contrib -= cfs_rq->tg_runnable_contrib;
if (abs(contrib) > cfs_rq->tg_runnable_contrib / 64) {
@@ -2465,7 +2689,8 @@ static inline void __update_group_entity_contrib(struct sched_entity *se)
static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
{
- __update_entity_runnable_avg(rq_clock_task(rq), &rq->avg, runnable);
+ __update_entity_runnable_avg(rq_clock_task(rq), cpu_of(rq), &rq->avg,
+ runnable, runnable);
__update_tg_runnable_avg(&rq->avg, &rq->cfs);
}
#else /* CONFIG_FAIR_GROUP_SCHED */
@@ -2483,7 +2708,7 @@ static inline void __update_task_entity_contrib(struct sched_entity *se)
/* avoid overflowing a 32-bit type w/ SCHED_LOAD_SCALE */
contrib = se->avg.runnable_avg_sum * scale_load_down(se->load.weight);
- contrib /= (se->avg.runnable_avg_period + 1);
+ contrib /= (se->avg.avg_period + 1);
se->avg.load_avg_contrib = scale_load(contrib);
}
@@ -2502,6 +2727,30 @@ static long __update_entity_load_avg_contrib(struct sched_entity *se)
return se->avg.load_avg_contrib - old_contrib;
}
+
+static inline void __update_task_entity_utilization(struct sched_entity *se)
+{
+ u32 contrib;
+
+ /* avoid overflowing a 32-bit type w/ SCHED_LOAD_SCALE */
+ contrib = se->avg.running_avg_sum * scale_load_down(SCHED_LOAD_SCALE);
+ contrib /= (se->avg.avg_period + 1);
+ se->avg.utilization_avg_contrib = scale_load(contrib);
+}
+
+static long __update_entity_utilization_avg_contrib(struct sched_entity *se)
+{
+ long old_contrib = se->avg.utilization_avg_contrib;
+
+ if (entity_is_task(se))
+ __update_task_entity_utilization(se);
+ else
+ se->avg.utilization_avg_contrib =
+ group_cfs_rq(se)->utilization_load_avg;
+
+ return se->avg.utilization_avg_contrib - old_contrib;
+}
+
static inline void subtract_blocked_load_contrib(struct cfs_rq *cfs_rq,
long load_contrib)
{
@@ -2518,7 +2767,8 @@ static inline void update_entity_load_avg(struct sched_entity *se,
int update_cfs_rq)
{
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- long contrib_delta;
+ long contrib_delta, utilization_delta;
+ int cpu = cpu_of(rq_of(cfs_rq));
u64 now;
/*
@@ -2530,18 +2780,22 @@ static inline void update_entity_load_avg(struct sched_entity *se,
else
now = cfs_rq_clock_task(group_cfs_rq(se));
- if (!__update_entity_runnable_avg(now, &se->avg, se->on_rq))
+ if (!__update_entity_runnable_avg(now, cpu, &se->avg, se->on_rq,
+ cfs_rq->curr == se))
return;
contrib_delta = __update_entity_load_avg_contrib(se);
+ utilization_delta = __update_entity_utilization_avg_contrib(se);
if (!update_cfs_rq)
return;
- if (se->on_rq)
+ if (se->on_rq) {
cfs_rq->runnable_load_avg += contrib_delta;
- else
+ cfs_rq->utilization_load_avg += utilization_delta;
+ } else {
subtract_blocked_load_contrib(cfs_rq, -contrib_delta);
+ }
}
/*
@@ -2616,6 +2870,7 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
}
cfs_rq->runnable_load_avg += se->avg.load_avg_contrib;
+ cfs_rq->utilization_load_avg += se->avg.utilization_avg_contrib;
/* we force update consideration on load-balancer moves */
update_cfs_rq_blocked_load(cfs_rq, !wakeup);
}
@@ -2634,6 +2889,7 @@ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq,
update_cfs_rq_blocked_load(cfs_rq, !sleep);
cfs_rq->runnable_load_avg -= se->avg.load_avg_contrib;
+ cfs_rq->utilization_load_avg -= se->avg.utilization_avg_contrib;
if (sleep) {
cfs_rq->blocked_load_avg += se->avg.load_avg_contrib;
se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
@@ -2971,6 +3227,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
*/
update_stats_wait_end(cfs_rq, se);
__dequeue_entity(cfs_rq, se);
+ update_entity_load_avg(se, 1);
}
update_stats_curr_start(cfs_rq, se);
@@ -3939,6 +4196,11 @@ static inline void hrtick_update(struct rq *rq)
}
#endif
+static inline bool energy_aware(void)
+{
+ return sched_feat(ENERGY_AWARE);
+}
+
/*
* The enqueue_task method is called before nr_running is
* increased. Here we update the fair scheduling stats and
@@ -3949,6 +4211,9 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
{
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
+ struct cpumask update_cpus;
+
+ cpumask_clear(&update_cpus);
for_each_sched_entity(se) {
if (se->on_rq)
@@ -3978,12 +4243,27 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
update_cfs_shares(cfs_rq);
update_entity_load_avg(se, 1);
+ /* track cpus that need to be re-evaluated */
+ cpumask_set_cpu(cpu_of(rq_of(cfs_rq)), &update_cpus);
}
+ /* !CONFIG_FAIR_GROUP_SCHED */
if (!se) {
update_rq_runnable_avg(rq, rq->nr_running);
add_nr_running(rq, 1);
+
+ /*
+ * FIXME for !CONFIG_FAIR_GROUP_SCHED it might be nice to
+ * typedef update_cpus into an int and skip all of the cpumask
+ * stuff
+ */
+ cpumask_set_cpu(cpu_of(rq), &update_cpus);
}
+
+ if (energy_aware())
+ if (!cpumask_empty(&update_cpus))
+ arch_eval_cpu_freq(&update_cpus);
+
hrtick_update(rq);
}
@@ -3999,6 +4279,9 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
struct cfs_rq *cfs_rq;
struct sched_entity *se = &p->se;
int task_sleep = flags & DEQUEUE_SLEEP;
+ struct cpumask update_cpus;
+
+ cpumask_clear(&update_cpus);
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
@@ -4039,12 +4322,27 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
update_cfs_shares(cfs_rq);
update_entity_load_avg(se, 1);
+ /* track runqueues/cpus that need to be re-evaluated */
+ cpumask_set_cpu(cpu_of(rq_of(cfs_rq)), &update_cpus);
}
+ /* !CONFIG_FAIR_GROUP_SCHED */
if (!se) {
sub_nr_running(rq, 1);
update_rq_runnable_avg(rq, 1);
+
+ /*
+ * FIXME for !CONFIG_FAIR_GROUP_SCHED it might be nice to
+ * typedef update_cpus into an int and skip all of the cpumask
+ * stuff
+ */
+ cpumask_set_cpu(cpu_of(rq), &update_cpus);
}
+
+ if (energy_aware())
+ if (!cpumask_empty(&update_cpus))
+ arch_eval_cpu_freq(&update_cpus);
+
hrtick_update(rq);
}
@@ -4088,11 +4386,16 @@ static unsigned long target_load(int cpu, int type)
return max(rq->cpu_load[type-1], total);
}
-static unsigned long capacity_of(int cpu)
+unsigned long capacity_of(int cpu)
{
return cpu_rq(cpu)->cpu_capacity;
}
+static unsigned long capacity_orig_of(int cpu)
+{
+ return cpu_rq(cpu)->cpu_capacity_orig;
+}
+
static unsigned long cpu_avg_load_per_task(int cpu)
{
struct rq *rq = cpu_rq(cpu);
@@ -4450,7 +4753,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
latest_idle_timestamp = rq->idle_stamp;
shallowest_idle_cpu = i;
}
- } else {
+ } else if (shallowest_idle_cpu == -1) {
load = weighted_cpuload(i);
if (load < min_load || (load == min_load && i == this_cpu)) {
min_load = load;
@@ -4506,6 +4809,33 @@ next:
done:
return target;
}
+/*
+ * get_cpu_usage returns the amount of capacity of a CPU that is used by CFS
+ * tasks. The unit of the return value must capacity so we can compare the
+ * usage with the capacity of the CPU that is available for CFS task (ie
+ * cpu_capacity).
+ * cfs.utilization_load_avg is the sum of running time of runnable tasks on a
+ * CPU. It represents the amount of utilization of a CPU in the range
+ * [0..SCHED_LOAD_SCALE]. The usage of a CPU can't be higher than the full
+ * capacity of the CPU because it's about the running time on this CPU.
+ * Nevertheless, cfs.utilization_load_avg can be higher than SCHED_LOAD_SCALE
+ * because of unfortunate rounding in avg_period and running_load_avg or just
+ * after migrating tasks until the average stabilizes with the new running
+ * time. So we need to check that the usage stays into the range
+ * [0..cpu_capacity_orig] and cap if necessary.
+ * Without capping the usage, a group could be seen as overloaded (CPU0 usage
+ * at 121% + CPU1 usage at 80%) whereas CPU1 has 20% of available capacity/
+ */
+int get_cpu_usage(int cpu)
+{
+ unsigned long usage = cpu_rq(cpu)->cfs.utilization_load_avg;
+ unsigned long capacity = capacity_orig_of(cpu);
+
+ if (usage >= SCHED_LOAD_SCALE)
+ return capacity;
+
+ return (usage * capacity) >> SCHED_LOAD_SHIFT;
+}
/*
* select_task_rq_fair: Select target runqueue for the waking task in domains
@@ -5170,7 +5500,7 @@ static bool migrate_improves_locality(struct task_struct *p, struct lb_env *env)
struct numa_group *numa_group = rcu_dereference(p->numa_group);
int src_nid, dst_nid;
- if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults_memory ||
+ if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults ||
!(env->sd->flags & SD_NUMA)) {
return false;
}
@@ -5209,7 +5539,7 @@ static bool migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER))
return false;
- if (!p->numa_faults_memory || !(env->sd->flags & SD_NUMA))
+ if (!p->numa_faults || !(env->sd->flags & SD_NUMA))
return false;
src_nid = cpu_to_node(env->src_cpu);
@@ -5635,12 +5965,12 @@ struct sg_lb_stats {
unsigned long sum_weighted_load; /* Weighted load of group's tasks */
unsigned long load_per_task;
unsigned long group_capacity;
+ unsigned long group_usage; /* Total usage of the group */
unsigned int sum_nr_running; /* Nr tasks running in the group */
- unsigned int group_capacity_factor;
unsigned int idle_cpus;
unsigned int group_weight;
enum group_type group_type;
- int group_has_free_capacity;
+ int group_no_capacity;
#ifdef CONFIG_NUMA_BALANCING
unsigned int nr_numa_running;
unsigned int nr_preferred_running;
@@ -5734,10 +6064,20 @@ unsigned long __weak arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
return default_scale_cpu_capacity(sd, cpu);
}
+void __weak arch_eval_cpu_freq(struct cpumask *cpus)
+{
+ return;
+}
+
+void __weak arch_scale_cpu_freq(void)
+{
+ return;
+}
+
static unsigned long scale_rt_capacity(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- u64 total, available, age_stamp, avg;
+ u64 total, used, age_stamp, avg;
s64 delta;
/*
@@ -5753,19 +6093,12 @@ static unsigned long scale_rt_capacity(int cpu)
total = sched_avg_period() + delta;
- if (unlikely(total < avg)) {
- /* Ensures that capacity won't end up being negative */
- available = 0;
- } else {
- available = total - avg;
- }
-
- if (unlikely((s64)total < SCHED_CAPACITY_SCALE))
- total = SCHED_CAPACITY_SCALE;
+ used = div_u64(avg, total);
- total >>= SCHED_CAPACITY_SHIFT;
+ if (likely(used < SCHED_CAPACITY_SCALE))
+ return SCHED_CAPACITY_SCALE - used;
- return div_u64(available, total);
+ return 1;
}
static void update_cpu_capacity(struct sched_domain *sd, int cpu)
@@ -5780,14 +6113,7 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu)
capacity >>= SCHED_CAPACITY_SHIFT;
- sdg->sgc->capacity_orig = capacity;
-
- if (sched_feat(ARCH_CAPACITY))
- capacity *= arch_scale_freq_capacity(sd, cpu);
- else
- capacity *= default_scale_capacity(sd, cpu);
-
- capacity >>= SCHED_CAPACITY_SHIFT;
+ cpu_rq(cpu)->cpu_capacity_orig = capacity;
capacity *= scale_rt_capacity(cpu);
capacity >>= SCHED_CAPACITY_SHIFT;
@@ -5803,7 +6129,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
{
struct sched_domain *child = sd->child;
struct sched_group *group, *sdg = sd->groups;
- unsigned long capacity, capacity_orig;
+ unsigned long capacity;
unsigned long interval;
interval = msecs_to_jiffies(sd->balance_interval);
@@ -5815,7 +6141,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
return;
}
- capacity_orig = capacity = 0;
+ capacity = 0;
if (child->flags & SD_OVERLAP) {
/*
@@ -5835,19 +6161,15 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
* Use capacity_of(), which is set irrespective of domains
* in update_cpu_capacity().
*
- * This avoids capacity/capacity_orig from being 0 and
+ * This avoids capacity from being 0 and
* causing divide-by-zero issues on boot.
- *
- * Runtime updates will correct capacity_orig.
*/
if (unlikely(!rq->sd)) {
- capacity_orig += capacity_of(cpu);
capacity += capacity_of(cpu);
continue;
}
sgc = rq->sd->groups->sgc;
- capacity_orig += sgc->capacity_orig;
capacity += sgc->capacity;
}
} else {
@@ -5858,39 +6180,24 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
group = child->groups;
do {
- capacity_orig += group->sgc->capacity_orig;
capacity += group->sgc->capacity;
group = group->next;
} while (group != child->groups);
}
- sdg->sgc->capacity_orig = capacity_orig;
sdg->sgc->capacity = capacity;
}
/*
- * Try and fix up capacity for tiny siblings, this is needed when
- * things like SD_ASYM_PACKING need f_b_g to select another sibling
- * which on its own isn't powerful enough.
- *
- * See update_sd_pick_busiest() and check_asym_packing().
+ * Check whether the capacity of the rq has been noticeably reduced by side
+ * activity. The imbalance_pct is used for the threshold.
+ * Return true is the capacity is reduced
*/
static inline int
-fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
+check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
{
- /*
- * Only siblings can have significantly less than SCHED_CAPACITY_SCALE
- */
- if (!(sd->flags & SD_SHARE_CPUCAPACITY))
- return 0;
-
- /*
- * If ~90% of the cpu_capacity is still there, we're good.
- */
- if (group->sgc->capacity * 32 > group->sgc->capacity_orig * 29)
- return 1;
-
- return 0;
+ return ((rq->cpu_capacity * sd->imbalance_pct) <
+ (rq->cpu_capacity_orig * 100));
}
/*
@@ -5928,37 +6235,54 @@ static inline int sg_imbalanced(struct sched_group *group)
}
/*
- * Compute the group capacity factor.
- *
- * Avoid the issue where N*frac(smt_capacity) >= 1 creates 'phantom' cores by
- * first dividing out the smt factor and computing the actual number of cores
- * and limit unit capacity with that.
+ * group_has_capacity returns true if the group has spare capacity that could
+ * be used by some tasks. We consider that a group has spare capacity if the
+ * number of task is smaller than the number of CPUs or if the usage is lower
+ * than the available capacity for CFS tasks. For the latter, we use a
+ * threshold to stabilize the state, to take into account the variance of the
+ * tasks' load and to return true if the available capacity in meaningful for
+ * the load balancer. As an example, an available capacity of 1% can appear
+ * but it doesn't make any benefit for the load balance.
*/
-static inline int sg_capacity_factor(struct lb_env *env, struct sched_group *group)
+static inline bool
+group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs)
{
- unsigned int capacity_factor, smt, cpus;
- unsigned int capacity, capacity_orig;
+ if ((sgs->group_capacity * 100) >
+ (sgs->group_usage * env->sd->imbalance_pct))
+ return true;
- capacity = group->sgc->capacity;
- capacity_orig = group->sgc->capacity_orig;
- cpus = group->group_weight;
+ if (sgs->sum_nr_running < sgs->group_weight)
+ return true;
- /* smt := ceil(cpus / capacity), assumes: 1 < smt_capacity < 2 */
- smt = DIV_ROUND_UP(SCHED_CAPACITY_SCALE * cpus, capacity_orig);
- capacity_factor = cpus / smt; /* cores */
+ return false;
+}
+
+/*
+ * group_is_overloaded returns true if the group has more tasks than it can
+ * handle. We consider that a group is overloaded if the number of tasks is
+ * greater than the number of CPUs and the tasks already use all available
+ * capacity for CFS tasks. For the latter, we use a threshold to stabilize
+ * the state, to take into account the variance of tasks' load and to return
+ * true if available capacity is no more meaningful for load balancer
+ */
+static inline bool
+group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs)
+{
+ if (sgs->sum_nr_running <= sgs->group_weight)
+ return false;
- capacity_factor = min_t(unsigned,
- capacity_factor, DIV_ROUND_CLOSEST(capacity, SCHED_CAPACITY_SCALE));
- if (!capacity_factor)
- capacity_factor = fix_small_capacity(env->sd, group);
+ if ((sgs->group_capacity * 100) <
+ (sgs->group_usage * env->sd->imbalance_pct))
+ return true;
- return capacity_factor;
+ return false;
}
-static enum group_type
-group_classify(struct sched_group *group, struct sg_lb_stats *sgs)
+static enum group_type group_classify(struct lb_env *env,
+ struct sched_group *group,
+ struct sg_lb_stats *sgs)
{
- if (sgs->sum_nr_running > sgs->group_capacity_factor)
+ if (sgs->group_no_capacity)
return group_overloaded;
if (sg_imbalanced(group))
@@ -5996,6 +6320,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
load = source_load(i, load_idx);
sgs->group_load += load;
+ sgs->group_usage += get_cpu_usage(i);
sgs->sum_nr_running += rq->cfs.h_nr_running;
if (rq->nr_running > 1)
@@ -6018,11 +6343,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
sgs->group_weight = group->group_weight;
- sgs->group_capacity_factor = sg_capacity_factor(env, group);
- sgs->group_type = group_classify(group, sgs);
- if (sgs->group_capacity_factor > sgs->sum_nr_running)
- sgs->group_has_free_capacity = 1;
+ sgs->group_no_capacity = group_is_overloaded(env, sgs);
+ sgs->group_type = group_classify(env, group, sgs);
}
/**
@@ -6144,17 +6467,20 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
/*
* In case the child domain prefers tasks go to siblings
- * first, lower the sg capacity factor to one so that we'll try
+ * first, lower the sg capacity so that we'll try
* and move all the excess tasks away. We lower the capacity
* of a group only if the local group has the capacity to fit
- * these excess tasks, i.e. nr_running < group_capacity_factor. The
- * extra check prevents the case where you always pull from the
- * heaviest group when it is already under-utilized (possible
- * with a large weight task outweighs the tasks on the system).
+ * these excess tasks. The extra check prevents the case where
+ * you always pull from the heaviest group when it is already
+ * under-utilized (possible with a large weight task outweighs
+ * the tasks on the system).
*/
if (prefer_sibling && sds->local &&
- sds->local_stat.group_has_free_capacity)
- sgs->group_capacity_factor = min(sgs->group_capacity_factor, 1U);
+ group_has_capacity(env, &sds->local_stat) &&
+ (sgs->sum_nr_running > 1)) {
+ sgs->group_no_capacity = 1;
+ sgs->group_type = group_overloaded;
+ }
if (update_sd_pick_busiest(env, sds, sg, sgs)) {
sds->busiest = sg;
@@ -6333,11 +6659,12 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
*/
if (busiest->group_type == group_overloaded &&
local->group_type == group_overloaded) {
- load_above_capacity =
- (busiest->sum_nr_running - busiest->group_capacity_factor);
-
- load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_CAPACITY_SCALE);
- load_above_capacity /= busiest->group_capacity;
+ load_above_capacity = busiest->sum_nr_running *
+ SCHED_LOAD_SCALE;
+ if (load_above_capacity > busiest->group_capacity)
+ load_above_capacity -= busiest->group_capacity;
+ else
+ load_above_capacity = ~0UL;
}
/*
@@ -6400,6 +6727,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
local = &sds.local_stat;
busiest = &sds.busiest_stat;
+ /* ASYM feature bypasses nice load balance check */
if ((env->idle == CPU_IDLE || env->idle == CPU_NEWLY_IDLE) &&
check_asym_packing(env, &sds))
return sds.busiest;
@@ -6420,8 +6748,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
goto force_balance;
/* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */
- if (env->idle == CPU_NEWLY_IDLE && local->group_has_free_capacity &&
- !busiest->group_has_free_capacity)
+ if (env->idle == CPU_NEWLY_IDLE && group_has_capacity(env, local) &&
+ busiest->group_no_capacity)
goto force_balance;
/*
@@ -6480,7 +6808,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
int i;
for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
- unsigned long capacity, capacity_factor, wl;
+ unsigned long capacity, wl;
enum fbq_type rt;
rq = cpu_rq(i);
@@ -6509,9 +6837,6 @@ static struct rq *find_busiest_queue(struct lb_env *env,
continue;
capacity = capacity_of(i);
- capacity_factor = DIV_ROUND_CLOSEST(capacity, SCHED_CAPACITY_SCALE);
- if (!capacity_factor)
- capacity_factor = fix_small_capacity(env->sd, group);
wl = weighted_cpuload(i);
@@ -6519,7 +6844,9 @@ static struct rq *find_busiest_queue(struct lb_env *env,
* When comparing with imbalance, use weighted_cpuload()
* which is not scaled with the cpu capacity.
*/
- if (capacity_factor && rq->nr_running == 1 && wl > env->imbalance)
+
+ if (rq->nr_running == 1 && wl > env->imbalance &&
+ !check_cpu_capacity(rq, env->sd))
continue;
/*
@@ -6567,6 +6894,28 @@ static int need_active_balance(struct lb_env *env)
return 1;
}
+ /*
+ * The dst_cpu is idle and the src_cpu CPU has only 1 CFS task.
+ * It's worth migrating the task if the src_cpu's capacity is reduced
+ * because of other sched_class or IRQs whereas capacity stays
+ * available on dst_cpu.
+ */
+ if ((env->idle != CPU_NOT_IDLE) &&
+ (env->src_rq->cfs.h_nr_running == 1)) {
+ unsigned long src_eff_capacity, dst_eff_capacity;
+
+ dst_eff_capacity = 100;
+ dst_eff_capacity *= capacity_of(env->dst_cpu);
+ dst_eff_capacity *= capacity_orig_of(env->src_cpu);
+
+ src_eff_capacity = sd->imbalance_pct;
+ src_eff_capacity *= capacity_of(env->src_cpu);
+ src_eff_capacity *= capacity_orig_of(env->dst_cpu);
+
+ if (src_eff_capacity < dst_eff_capacity)
+ return 1;
+ }
+
return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
}
@@ -6666,6 +7015,9 @@ redo:
schedstat_add(sd, lb_imbalance[idle], env.imbalance);
+ env.src_cpu = busiest->cpu;
+ env.src_rq = busiest;
+
ld_moved = 0;
if (busiest->nr_running > 1) {
/*
@@ -6675,8 +7027,6 @@ redo:
* correctly treated as an imbalance.
*/
env.flags |= LBF_ALL_PINNED;
- env.src_cpu = busiest->cpu;
- env.src_rq = busiest;
env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
more_balance:
@@ -7376,22 +7726,25 @@ end:
/*
* Current heuristic for kicking the idle load balancer in the presence
- * of an idle cpu is the system.
+ * of an idle cpu in the system.
* - This rq has more than one task.
- * - At any scheduler domain level, this cpu's scheduler group has multiple
- * busy cpu's exceeding the group's capacity.
+ * - This rq has at least one CFS task and the capacity of the CPU is
+ * significantly reduced because of RT tasks or IRQs.
+ * - At parent of LLC scheduler domain level, this cpu's scheduler group has
+ * multiple busy cpu.
* - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
* domain span are idle.
*/
-static inline int nohz_kick_needed(struct rq *rq)
+static inline bool nohz_kick_needed(struct rq *rq)
{
unsigned long now = jiffies;
struct sched_domain *sd;
struct sched_group_capacity *sgc;
int nr_busy, cpu = rq->cpu;
+ bool kick = false;
if (unlikely(rq->idle_balance))
- return 0;
+ return false;
/*
* We may be recently in ticked or tickless idle mode. At the first
@@ -7405,38 +7758,44 @@ static inline int nohz_kick_needed(struct rq *rq)
* balancing.
*/
if (likely(!atomic_read(&nohz.nr_cpus)))
- return 0;
+ return false;
if (time_before(now, nohz.next_balance))
- return 0;
+ return false;
if (rq->nr_running >= 2)
- goto need_kick;
+ return true;
rcu_read_lock();
sd = rcu_dereference(per_cpu(sd_busy, cpu));
-
if (sd) {
sgc = sd->groups->sgc;
nr_busy = atomic_read(&sgc->nr_busy_cpus);
- if (nr_busy > 1)
- goto need_kick_unlock;
+ if (nr_busy > 1) {
+ kick = true;
+ goto unlock;
+ }
+
}
- sd = rcu_dereference(per_cpu(sd_asym, cpu));
+ sd = rcu_dereference(rq->sd);
+ if (sd) {
+ if ((rq->cfs.h_nr_running >= 1) &&
+ check_cpu_capacity(rq, sd)) {
+ kick = true;
+ goto unlock;
+ }
+ }
+ sd = rcu_dereference(per_cpu(sd_asym, cpu));
if (sd && (cpumask_first_and(nohz.idle_cpus_mask,
sched_domain_span(sd)) < cpu))
- goto need_kick_unlock;
+ kick = true;
+unlock:
rcu_read_unlock();
- return 0;
-
-need_kick_unlock:
- rcu_read_unlock();
-need_kick:
- return 1;
+ return kick;
}
#else
static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { }
@@ -7460,6 +7819,9 @@ static void run_rebalance_domains(struct softirq_action *h)
* stopped.
*/
nohz_idle_balance(this_rq, idle);
+
+ if (energy_aware())
+ arch_scale_cpu_freq();
}
/*
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 90284d117fe6..199ee3a62fbc 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -83,3 +83,9 @@ SCHED_FEAT(NUMA_FAVOUR_HIGHER, true)
*/
SCHED_FEAT(NUMA_RESIST_LOWER, false)
#endif
+
+/*
+ * Energy aware scheduling. Use platform energy model to guide scheduling
+ * decisions optimizing for energy efficiency.
+ */
+SCHED_FEAT(ENERGY_AWARE, false)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index d024e6ce30ba..3d14312db7ea 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1351,16 +1351,22 @@ out:
static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
{
- if (rq->curr->nr_cpus_allowed == 1)
+ /*
+ * Current can't be migrated, useless to reschedule,
+ * let's hope p can move out.
+ */
+ if (rq->curr->nr_cpus_allowed == 1 ||
+ !cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
return;
+ /*
+ * p is migratable, so let's not schedule it and
+ * see if it is pushed or pulled somewhere else.
+ */
if (p->nr_cpus_allowed != 1
&& cpupri_find(&rq->rd->cpupri, p, NULL))
return;
- if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL))
- return;
-
/*
* There appears to be other cpus that can accept
* current and none to run 'p', so lets reschedule
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 24156c8434d1..770c18cd6bee 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -176,6 +176,25 @@ struct dl_bw {
u64 bw, total_bw;
};
+static inline
+void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
+{
+ dl_b->total_bw -= tsk_bw;
+}
+
+static inline
+void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
+{
+ dl_b->total_bw += tsk_bw;
+}
+
+static inline
+bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
+{
+ return dl_b->bw != -1 &&
+ dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
+}
+
extern struct mutex sched_domains_mutex;
#ifdef CONFIG_CGROUP_SCHED
@@ -313,6 +332,9 @@ struct cfs_bandwidth { };
#endif /* CONFIG_CGROUP_SCHED */
+extern unsigned long capacity_of(int cpu);
+extern int get_cpu_usage(int cpu);
+
/* CFS-related fields in a runqueue */
struct cfs_rq {
struct load_weight load;
@@ -343,8 +365,14 @@ struct cfs_rq {
* Under CFS, load is tracked on a per-entity basis and aggregated up.
* This allows for the description of both thread and group usage (in
* the FAIR_GROUP_SCHED case).
+ * runnable_load_avg is the sum of the load_avg_contrib of the
+ * sched_entities on the rq.
+ * blocked_load_avg is similar to runnable_load_avg except that its
+ * the blocked sched_entities on the rq.
+ * utilization_load_avg is the sum of the average running time of the
+ * sched_entities on the rq.
*/
- unsigned long runnable_load_avg, blocked_load_avg;
+ unsigned long runnable_load_avg, blocked_load_avg, utilization_load_avg;
atomic64_t decay_counter;
u64 last_decay;
atomic_long_t removed_load;
@@ -579,6 +607,7 @@ struct rq {
struct sched_domain *sd;
unsigned long cpu_capacity;
+ unsigned long cpu_capacity_orig;
unsigned char idle_balance;
/* For active balancing */
@@ -678,7 +707,25 @@ static inline u64 rq_clock_task(struct rq *rq)
return rq->clock_task;
}
+#ifdef CONFIG_NUMA
+enum numa_topology_type {
+ NUMA_DIRECT,
+ NUMA_GLUELESS_MESH,
+ NUMA_BACKPLANE,
+};
+extern enum numa_topology_type sched_numa_topology_type;
+extern int sched_max_numa_distance;
+extern bool find_numa_distance(int distance);
+#endif
+
#ifdef CONFIG_NUMA_BALANCING
+/* The regions in numa_faults array from task_struct */
+enum numa_faults_stats {
+ NUMA_MEM = 0,
+ NUMA_CPU,
+ NUMA_MEMBUF,
+ NUMA_CPUBUF
+};
extern void sched_setnuma(struct task_struct *p, int node);
extern int migrate_task_to(struct task_struct *p, int cpu);
extern int migrate_swap(struct task_struct *, struct task_struct *);
@@ -752,7 +799,7 @@ struct sched_group_capacity {
* CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
* for a single CPU.
*/
- unsigned int capacity, capacity_orig;
+ unsigned int capacity;
unsigned long next_update;
int imbalance; /* XXX unrelated to capacity but shared group state */
/*
@@ -1127,6 +1174,11 @@ struct sched_class {
void (*task_fork) (struct task_struct *p);
void (*task_dead) (struct task_struct *p);
+ /*
+ * The switched_from() call is allowed to drop rq->lock, therefore we
+ * cannot assume the switched_from/switched_to pair is serliazed by
+ * rq->lock. They are however serialized by p->pi_lock.
+ */
void (*switched_from) (struct rq *this_rq, struct task_struct *task);
void (*switched_to) (struct rq *this_rq, struct task_struct *task);
void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
@@ -1306,9 +1358,11 @@ static inline int hrtick_enabled(struct rq *rq)
#ifdef CONFIG_SMP
extern void sched_avg_update(struct rq *rq);
+extern unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu);
+
static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
{
- rq->rt_avg += rt_delta;
+ rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
sched_avg_update(rq);
}
#else
@@ -1502,6 +1556,7 @@ extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
extern void print_cfs_stats(struct seq_file *m, int cpu);
extern void print_rt_stats(struct seq_file *m, int cpu);
+extern void print_dl_stats(struct seq_file *m, int cpu);
extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 5a62915f47a8..852143a79f36 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -9,6 +9,7 @@
#include <linux/mm.h>
#include <linux/wait.h>
#include <linux/hash.h>
+#include <linux/kthread.h>
void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *key)
{
@@ -297,6 +298,71 @@ int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *
}
EXPORT_SYMBOL(autoremove_wake_function);
+static inline bool is_kthread_should_stop(void)
+{
+ return (current->flags & PF_KTHREAD) && kthread_should_stop();
+}
+
+/*
+ * DEFINE_WAIT_FUNC(wait, woken_wake_func);
+ *
+ * add_wait_queue(&wq, &wait);
+ * for (;;) {
+ * if (condition)
+ * break;
+ *
+ * p->state = mode; condition = true;
+ * smp_mb(); // A smp_wmb(); // C
+ * if (!wait->flags & WQ_FLAG_WOKEN) wait->flags |= WQ_FLAG_WOKEN;
+ * schedule() try_to_wake_up();
+ * p->state = TASK_RUNNING; ~~~~~~~~~~~~~~~~~~
+ * wait->flags &= ~WQ_FLAG_WOKEN; condition = true;
+ * smp_mb() // B smp_wmb(); // C
+ * wait->flags |= WQ_FLAG_WOKEN;
+ * }
+ * remove_wait_queue(&wq, &wait);
+ *
+ */
+long wait_woken(wait_queue_t *wait, unsigned mode, long timeout)
+{
+ set_current_state(mode); /* A */
+ /*
+ * The above implies an smp_mb(), which matches with the smp_wmb() from
+ * woken_wake_function() such that if we observe WQ_FLAG_WOKEN we must
+ * also observe all state before the wakeup.
+ */
+ if (!(wait->flags & WQ_FLAG_WOKEN) && !is_kthread_should_stop())
+ timeout = schedule_timeout(timeout);
+ __set_current_state(TASK_RUNNING);
+
+ /*
+ * The below implies an smp_mb(), it too pairs with the smp_wmb() from
+ * woken_wake_function() such that we must either observe the wait
+ * condition being true _OR_ WQ_FLAG_WOKEN such that we will not miss
+ * an event.
+ */
+ set_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */
+
+ return timeout;
+}
+EXPORT_SYMBOL(wait_woken);
+
+int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
+{
+ /*
+ * Although this function is called under waitqueue lock, LOCK
+ * doesn't imply write barrier and the users expects write
+ * barrier semantics on wakeup functions. The following
+ * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
+ * and is paired with set_mb() in wait_woken().
+ */
+ smp_wmb(); /* C */
+ wait->flags |= WQ_FLAG_WOKEN;
+
+ return default_wake_function(wait, mode, sync, key);
+}
+EXPORT_SYMBOL(woken_wake_function);
+
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *arg)
{
struct wait_bit_key *key = arg;
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index eb89e1807408..f032fb5284e3 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -110,7 +110,7 @@ static int smpboot_thread_fn(void *data)
set_current_state(TASK_INTERRUPTIBLE);
preempt_disable();
if (kthread_should_stop()) {
- set_current_state(TASK_RUNNING);
+ __set_current_state(TASK_RUNNING);
preempt_enable();
if (ht->cleanup)
ht->cleanup(td->cpu, cpu_online(td->cpu));
@@ -136,26 +136,27 @@ static int smpboot_thread_fn(void *data)
/* Check for state change setup */
switch (td->status) {
case HP_THREAD_NONE:
+ __set_current_state(TASK_RUNNING);
preempt_enable();
if (ht->setup)
ht->setup(td->cpu);
td->status = HP_THREAD_ACTIVE;
- preempt_disable();
- break;
+ continue;
+
case HP_THREAD_PARKED:
+ __set_current_state(TASK_RUNNING);
preempt_enable();
if (ht->unpark)
ht->unpark(td->cpu);
td->status = HP_THREAD_ACTIVE;
- preempt_disable();
- break;
+ continue;
}
if (!ht->thread_should_run(td->cpu)) {
- preempt_enable();
+ preempt_enable_no_resched();
schedule();
} else {
- set_current_state(TASK_RUNNING);
+ __set_current_state(TASK_RUNNING);
preempt_enable();
ht->thread_fn(td->cpu);
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f33527ba62ca..947663d2935a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -398,7 +398,8 @@ static struct ctl_table kern_table[] = {
.data = &sysctl_numa_balancing_scan_size,
.maxlen = sizeof(unsigned int),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &one,
},
{
.procname = "numa_balancing",
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index af73bc3acb40..410dd5e76c41 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -101,11 +101,11 @@ static struct rfcomm_session *rfcomm_session_del(struct rfcomm_session *s);
#define __get_rpn_stop_bits(line) (((line) >> 2) & 0x1)
#define __get_rpn_parity(line) (((line) >> 3) & 0x7)
+static DECLARE_WAIT_QUEUE_HEAD(rfcomm_wq);
+
static void rfcomm_schedule(void)
{
- if (!rfcomm_thread)
- return;
- wake_up_process(rfcomm_thread);
+ wake_up_all(&rfcomm_wq);
}
/* ---- RFCOMM FCS computation ---- */
@@ -2086,24 +2086,22 @@ static void rfcomm_kill_listener(void)
static int rfcomm_run(void *unused)
{
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
BT_DBG("");
set_user_nice(current, -10);
rfcomm_add_listener(BDADDR_ANY);
- while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
-
- if (kthread_should_stop())
- break;
+ add_wait_queue(&rfcomm_wq, &wait);
+ while (!kthread_should_stop()) {
/* Process stuff */
rfcomm_process_sessions();
- schedule();
+ wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
- __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&rfcomm_wq, &wait);
rfcomm_kill_listener();
diff --git a/net/core/dev.c b/net/core/dev.c
index b793e3521a36..c5a9d73147a6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7196,11 +7196,10 @@ static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
*/
struct net *net;
bool unregistering;
- DEFINE_WAIT(wait);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ add_wait_queue(&netdev_unregistering_wq, &wait);
for (;;) {
- prepare_to_wait(&netdev_unregistering_wq, &wait,
- TASK_UNINTERRUPTIBLE);
unregistering = false;
rtnl_lock();
list_for_each_entry(net, net_list, exit_list) {
@@ -7212,9 +7211,10 @@ static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
if (!unregistering)
break;
__rtnl_unlock();
- schedule();
+
+ wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
- finish_wait(&netdev_unregistering_wq, &wait);
+ remove_wait_queue(&netdev_unregistering_wq, &wait);
}
static void __net_exit default_device_exit_batch(struct list_head *net_list)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index a6882686ca3a..b095296f711f 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -365,11 +365,10 @@ static void rtnl_lock_unregistering_all(void)
{
struct net *net;
bool unregistering;
- DEFINE_WAIT(wait);
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ add_wait_queue(&netdev_unregistering_wq, &wait);
for (;;) {
- prepare_to_wait(&netdev_unregistering_wq, &wait,
- TASK_UNINTERRUPTIBLE);
unregistering = false;
rtnl_lock();
for_each_net(net) {
@@ -381,9 +380,10 @@ static void rtnl_lock_unregistering_all(void)
if (!unregistering)
break;
__rtnl_unlock();
- schedule();
+
+ wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
- finish_wait(&netdev_unregistering_wq, &wait);
+ remove_wait_queue(&netdev_unregistering_wq, &wait);
}
/**