feature is too high then the rate the kernel samples for NUMA hinting
faults may be controlled by the numa_balancing_scan_period_min_ms,
numa_balancing_scan_delay_ms, numa_balancing_scan_period_max_ms,
-numa_balancing_scan_size_mb, numa_balancing_settle_count sysctls and
-numa_balancing_migrate_deferred.
+numa_balancing_scan_size_mb, and numa_balancing_settle_count sysctls.
==============================================================
numa_balancing_scan_size_mb is how many megabytes worth of pages are
scanned for a given scan.
-numa_balancing_migrate_deferred is how many page migrations get skipped
-unconditionally, after a page migration is skipped because a page is shared
-with other tasks. This reduces page migration overhead, and determines
-how much stronger the "move task near its memory" policy scheduler becomes,
-versus the "move memory near its task" memory management policy, for workloads
-with shared memory.
-
==============================================================
osrelease, ostype & version:
#include <linux/uaccess.h>
#include <linux/random.h>
#include <linux/hw_breakpoint.h>
-#include <linux/cpuidle.h>
#include <linux/leds.h>
#include <linux/reboot.h>
void (*arm_pm_idle)(void);
-static void default_idle(void)
+/*
+ * Called from the core idle loop.
+ */
+
+void arch_cpu_idle(void)
{
if (arm_pm_idle)
arm_pm_idle();
}
#endif
-/*
- * Called from the core idle loop.
- */
-void arch_cpu_idle(void)
-{
- if (cpuidle_idle_call())
- default_idle();
-}
-
/*
* Called by kexec, immediately prior to machine_kexec().
*
#define MIN_SPU_TIMESLICE max(5 * HZ / (1000 * SPUSCHED_TICK), 1)
#define DEF_SPU_TIMESLICE (100 * HZ / (1000 * SPUSCHED_TICK))
-#define MAX_USER_PRIO (MAX_PRIO - MAX_RT_PRIO)
#define SCALE_PRIO(x, prio) \
max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_SPU_TIMESLICE)
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/root_dev.h>
-#include <linux/cpuidle.h>
#include <linux/of.h>
#include <linux/kexec.h>
static void pseries_lpar_idle(void)
{
- /* This would call on the cpuidle framework, and the back-end pseries
- * driver to go to idle states
+ /*
+ * Default handler to go into low thread priority and possibly
+ * low power mode by cedeing processor to hypervisor
*/
- if (cpuidle_idle_call()) {
- /* On error, execute default handler
- * to go into low thread priority and possibly
- * low power mode by cedeing processor to hypervisor
- */
- /* Indicate to hypervisor that we are idle. */
- get_lppaca()->idle = 1;
+ /* Indicate to hypervisor that we are idle. */
+ get_lppaca()->idle = 1;
- /*
- * Yield the processor to the hypervisor. We return if
- * an external interrupt occurs (which are driven prior
- * to returning here) or if a prod occurs from another
- * processor. When returning here, external interrupts
- * are enabled.
- */
- cede_processor();
+ /*
+ * Yield the processor to the hypervisor. We return if
+ * an external interrupt occurs (which are driven prior
+ * to returning here) or if a prod occurs from another
+ * processor. When returning here, external interrupts
+ * are enabled.
+ */
+ cede_processor();
- get_lppaca()->idle = 0;
- }
+ get_lppaca()->idle = 0;
}
/*
#include <linux/thread_info.h>
#include <linux/irqflags.h>
#include <linux/smp.h>
-#include <linux/cpuidle.h>
#include <linux/atomic.h>
#include <asm/pgalloc.h>
#include <asm/smp.h>
void arch_cpu_idle(void)
{
- if (cpuidle_idle_call())
- sh_idle();
+ sh_idle();
}
void __init select_idle_routine(void)
*/
void arch_cpu_idle(void)
{
- if (cpuidle_idle_call())
- x86_idle();
- else
- local_irq_enable();
+ x86_idle();
}
/*
#include <asm/reg.h>
#include <asm/machdep.h>
#include <asm/firmware.h>
+#include <asm/runlatch.h>
#include <asm/plpar_wrappers.h>
struct cpuidle_driver pseries_idle_driver = {
static inline void idle_loop_prolog(unsigned long *in_purr)
{
+ ppc64_runlatch_off();
*in_purr = mfspr(SPRN_PURR);
/*
* Indicate to the HV that we are idle. Now would be
wait_cycles += mfspr(SPRN_PURR) - in_purr;
get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
get_lppaca()->idle = 0;
+
+ if (irqs_disabled())
+ local_irq_enable();
+ ppc64_runlatch_on();
}
static int snooze_loop(struct cpuidle_device *dev,
#include <uapi/linux/sched.h>
+#include <linux/sched/prio.h>
+
struct sched_param {
int sched_priority;
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
+ int depth;
struct sched_entity *parent;
/* rq on which this entity is (to be) queued: */
struct cfs_rq *cfs_rq;
unsigned int numa_scan_period;
unsigned int numa_scan_period_max;
int numa_preferred_nid;
- int numa_migrate_deferred;
unsigned long numa_migrate_retry;
u64 node_stamp; /* migration stamp */
+ u64 last_task_numa_placement;
+ u64 last_sum_exec_runtime;
struct callback_head numa_work;
struct list_head numa_entry;
* Scheduling placement decisions are made based on the these counts.
* The values remain static for the duration of a PTE scan
*/
- unsigned long *numa_faults;
+ unsigned long *numa_faults_memory;
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
- * decay and these values are copied.
+ * 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_buffer;
+ unsigned long *numa_faults_cpu;
+ unsigned long *numa_faults_buffer_cpu;
/*
* numa_faults_locality tracks if faults recorded during the last
extern pid_t task_numa_group_id(struct task_struct *p);
extern void set_numabalancing_state(bool enabled);
extern void task_numa_free(struct task_struct *p);
-
-extern unsigned int sysctl_numa_balancing_migrate_deferred;
+extern bool should_numa_migrate_memory(struct task_struct *p, struct page *page,
+ int src_nid, int dst_cpu);
#else
static inline void task_numa_fault(int last_node, int node, int pages,
int flags)
static inline void task_numa_free(struct task_struct *p)
{
}
+static inline bool should_numa_migrate_memory(struct task_struct *p,
+ struct page *page, int src_nid, int dst_cpu)
+{
+ return true;
+}
#endif
static inline struct pid *task_pid(struct task_struct *task)
extern bool yield_to(struct task_struct *p, bool preempt);
extern void set_user_nice(struct task_struct *p, long nice);
extern int task_prio(const struct task_struct *p);
-extern int task_nice(const struct task_struct *p);
+/**
+ * task_nice - return the nice value of a given task.
+ * @p: the task in question.
+ *
+ * Return: The nice value [ -20 ... 0 ... 19 ].
+ */
+static inline int task_nice(const struct task_struct *p)
+{
+ return PRIO_TO_NICE((p)->static_prio);
+}
extern int can_nice(const struct task_struct *p, const int nice);
extern int task_curr(const struct task_struct *p);
extern int idle_cpu(int cpu);
--- /dev/null
+#ifndef _SCHED_PRIO_H
+#define _SCHED_PRIO_H
+
+/*
+ * Priority of a process goes from 0..MAX_PRIO-1, valid RT
+ * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
+ * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
+ * values are inverted: lower p->prio value means higher priority.
+ *
+ * The MAX_USER_RT_PRIO value allows the actual maximum
+ * RT priority to be separate from the value exported to
+ * user-space. This allows kernel threads to set their
+ * priority to a value higher than any user task. Note:
+ * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
+ */
+
+#define MAX_USER_RT_PRIO 100
+#define MAX_RT_PRIO MAX_USER_RT_PRIO
+
+#define MAX_PRIO (MAX_RT_PRIO + 40)
+#define DEFAULT_PRIO (MAX_RT_PRIO + 20)
+
+/*
+ * Convert user-nice values [ -20 ... 0 ... 19 ]
+ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
+ * and back.
+ */
+#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
+#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
+
+/*
+ * 'User priority' is the nice value converted to something we
+ * can work with better when scaling various scheduler parameters,
+ * it's a [ 0 ... 39 ] range.
+ */
+#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
+#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
+#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
+
+#endif /* _SCHED_PRIO_H */
#ifndef _SCHED_RT_H
#define _SCHED_RT_H
-/*
- * Priority of a process goes from 0..MAX_PRIO-1, valid RT
- * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
- * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
- * values are inverted: lower p->prio value means higher priority.
- *
- * The MAX_USER_RT_PRIO value allows the actual maximum
- * RT priority to be separate from the value exported to
- * user-space. This allows kernel threads to set their
- * priority to a value higher than any user task. Note:
- * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
- */
-
-#define MAX_USER_RT_PRIO 100
-#define MAX_RT_PRIO MAX_USER_RT_PRIO
-
-#define MAX_PRIO (MAX_RT_PRIO + 40)
-#define DEFAULT_PRIO (MAX_RT_PRIO + 20)
+#include <linux/sched/prio.h>
static inline int rt_prio(int prio)
{
obj-y += locking/
obj-y += power/
obj-y += printk/
-obj-y += cpu/
obj-y += irq/
obj-y += rcu/
+++ /dev/null
-obj-y = idle.o
*/
#include <linux/sched.h>
#include <linux/cpu.h>
+#include <linux/cpuidle.h>
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
if (!current_clr_polling_and_test()) {
stop_critical_timings();
rcu_idle_enter();
- arch_cpu_idle();
- WARN_ON_ONCE(irqs_disabled());
+ if (cpuidle_idle_call())
+ arch_cpu_idle();
+ if (WARN_ON_ONCE(irqs_disabled()))
+ local_irq_enable();
rcu_idle_exit();
start_critical_timings();
} else {
obj-y += core.o proc.o clock.o cputime.o
obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
-obj-y += wait.o completion.o
+obj-y += wait.o completion.o idle.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
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 = NULL;
- p->numa_faults_buffer = NULL;
+ p->numa_faults_memory = NULL;
+ p->numa_faults_buffer_memory = NULL;
+ p->last_task_numa_placement = 0;
+ p->last_sum_exec_runtime = 0;
INIT_LIST_HEAD(&p->numa_entry);
p->numa_group = NULL;
#ifdef CONFIG_SMP
-/* assumes rq->lock is held */
-static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
-{
- if (prev->sched_class->pre_schedule)
- prev->sched_class->pre_schedule(rq, prev);
-}
-
/* rq->lock is NOT held, but preemption is disabled */
static inline void post_schedule(struct rq *rq)
{
#else
-static inline void pre_schedule(struct rq *rq, struct task_struct *p)
-{
-}
-
static inline void post_schedule(struct rq *rq)
{
}
schedstat_inc(this_rq(), sched_count);
}
-static void put_prev_task(struct rq *rq, struct task_struct *prev)
-{
- if (prev->on_rq || rq->skip_clock_update < 0)
- update_rq_clock(rq);
- prev->sched_class->put_prev_task(rq, prev);
-}
-
/*
* Pick up the highest-prio task:
*/
static inline struct task_struct *
-pick_next_task(struct rq *rq)
+pick_next_task(struct rq *rq, struct task_struct *prev)
{
const struct sched_class *class;
struct task_struct *p;
* Optimization: we know that if all tasks are in
* the fair class we can call that function directly:
*/
- if (likely(rq->nr_running == rq->cfs.h_nr_running)) {
- p = fair_sched_class.pick_next_task(rq);
+ if (likely(prev->sched_class == &fair_sched_class &&
+ rq->nr_running == rq->cfs.h_nr_running)) {
+ p = fair_sched_class.pick_next_task(rq, prev);
if (likely(p))
return p;
}
for_each_class(class) {
- p = class->pick_next_task(rq);
+ p = class->pick_next_task(rq, prev);
if (p)
return p;
}
switch_count = &prev->nvcsw;
}
- pre_schedule(rq, prev);
-
- if (unlikely(!rq->nr_running))
- idle_balance(cpu, rq);
+ if (prev->on_rq || rq->skip_clock_update < 0)
+ update_rq_clock(rq);
- put_prev_task(rq, prev);
- next = pick_next_task(rq);
+ next = pick_next_task(rq, prev);
clear_tsk_need_resched(prev);
clear_preempt_need_resched();
rq->skip_clock_update = 0;
unsigned long flags;
struct rq *rq;
- if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
+ if (task_nice(p) == nice || nice < -20 || nice > 19)
return;
/*
* We have to be careful, if called from sys_setpriority(),
if (increment > 40)
increment = 40;
- nice = TASK_NICE(current) + increment;
+ nice = task_nice(current) + increment;
if (nice < -20)
nice = -20;
if (nice > 19)
return p->prio - MAX_RT_PRIO;
}
-/**
- * task_nice - return the nice value of a given task.
- * @p: the task in question.
- *
- * Return: The nice value [ -20 ... 0 ... 19 ].
- */
-int task_nice(const struct task_struct *p)
-{
- return TASK_NICE(p);
-}
-EXPORT_SYMBOL(task_nice);
-
/**
* idle_cpu - is a given cpu idle currently?
* @cpu: the processor in question.
*/
if (user && !capable(CAP_SYS_NICE)) {
if (fair_policy(policy)) {
- if (attr->sched_nice < TASK_NICE(p) &&
+ if (attr->sched_nice < task_nice(p) &&
!can_nice(p, attr->sched_nice))
return -EPERM;
}
* SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
*/
if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
- if (!can_nice(p, TASK_NICE(p)))
+ if (!can_nice(p, task_nice(p)))
return -EPERM;
}
* If not changing anything there's no need to proceed further:
*/
if (unlikely(policy == p->policy)) {
- if (fair_policy(policy) && attr->sched_nice != TASK_NICE(p))
+ if (fair_policy(policy) && attr->sched_nice != task_nice(p))
goto change;
if (rt_policy(policy) && attr->sched_priority != p->rt_priority)
goto change;
else if (task_has_rt_policy(p))
attr.sched_priority = p->rt_priority;
else
- attr.sched_nice = TASK_NICE(p);
+ attr.sched_nice = task_nice(p);
rcu_read_unlock();
if (rq->nr_running == 1)
break;
- next = pick_next_task(rq);
+ next = pick_next_task(rq, NULL);
BUG_ON(!next);
next->sched_class->put_prev_task(rq, next);
static struct ctl_table *
sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
- struct ctl_table *table = sd_alloc_ctl_entry(13);
+ struct ctl_table *table = sd_alloc_ctl_entry(14);
if (table == NULL)
return NULL;
sizeof(int), 0644, proc_dointvec_minmax, false);
set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[11], "name", sd->name,
+ set_table_entry(&table[11], "max_newidle_lb_cost",
+ &sd->max_newidle_lb_cost,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[12], "name", sd->name,
CORENAME_MAX_SIZE, 0444, proc_dostring, false);
- /* &table[12] is terminator */
+ /* &table[13] is terminator */
return table;
}
* Renice negative nice level userspace
* tasks back to 0:
*/
- if (TASK_NICE(p) < 0 && p->mm)
+ if (task_nice(p) < 0 && p->mm)
set_user_nice(p, 0);
continue;
}
p->utimescaled += cputime_scaled;
account_group_user_time(p, cputime);
- index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
+ index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
/* Add user time to cpustat. */
task_group_account_field(p, index, (__force u64) cputime);
p->gtime += cputime;
/* Add guest time to cpustat. */
- if (TASK_NICE(p) > 0) {
+ if (task_nice(p) > 0) {
cpustat[CPUTIME_NICE] += (__force u64) cputime;
cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;
} else {
resched_task(rq->curr);
}
+static int pull_dl_task(struct rq *this_rq);
+
#endif /* CONFIG_SMP */
/*
return rb_entry(left, struct sched_dl_entity, rb_node);
}
-struct task_struct *pick_next_task_dl(struct rq *rq)
+struct task_struct *pick_next_task_dl(struct rq *rq, struct task_struct *prev)
{
struct sched_dl_entity *dl_se;
struct task_struct *p;
dl_rq = &rq->dl;
+#ifdef CONFIG_SMP
+ if (dl_task(prev))
+ pull_dl_task(rq);
+#endif
+
if (unlikely(!dl_rq->dl_nr_running))
return NULL;
+ if (prev)
+ prev->sched_class->put_prev_task(rq, prev);
+
dl_se = pick_next_dl_entity(rq, dl_rq);
BUG_ON(!dl_se);
return ret;
}
-static void pre_schedule_dl(struct rq *rq, struct task_struct *prev)
-{
- /* Try to pull other tasks here */
- if (dl_task(prev))
- pull_dl_task(rq);
-}
-
static void post_schedule_dl(struct rq *rq)
{
push_dl_tasks(rq);
if (unlikely(p->dl.dl_throttled))
return;
- if (p->on_rq || rq->curr != p) {
+ if (p->on_rq && rq->curr != p) {
#ifdef CONFIG_SMP
if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p))
/* Only reschedule if pushing failed */
.set_cpus_allowed = set_cpus_allowed_dl,
.rq_online = rq_online_dl,
.rq_offline = rq_offline_dl,
- .pre_schedule = pre_schedule_dl,
.post_schedule = post_schedule_dl,
.task_woken = task_woken_dl,
#endif
P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
+ P64(max_idle_balance_cost);
#endif
P(ttwu_count);
unsigned long nr_faults = -1;
int cpu_current, home_node;
- if (p->numa_faults)
- nr_faults = p->numa_faults[2*node + i];
+ if (p->numa_faults_memory)
+ nr_faults = p->numa_faults_memory[2*node + i];
cpu_current = !i ? (task_node(p) == node) :
(pol && node_isset(node, pol->v.nodes));
home_node = (p->numa_preferred_nid == node);
- SEQ_printf(m, "numa_faults, %d, %d, %d, %d, %ld\n",
+ SEQ_printf(m, "numa_faults_memory, %d, %d, %d, %d, %ld\n",
i, node, cpu_current, home_node, nr_faults);
}
}
list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
/* Do the two (enqueued) entities belong to the same group ? */
-static inline int
+static inline struct cfs_rq *
is_same_group(struct sched_entity *se, struct sched_entity *pse)
{
if (se->cfs_rq == pse->cfs_rq)
- return 1;
+ return se->cfs_rq;
- return 0;
+ return NULL;
}
static inline struct sched_entity *parent_entity(struct sched_entity *se)
return se->parent;
}
-/* return depth at which a sched entity is present in the hierarchy */
-static inline int depth_se(struct sched_entity *se)
-{
- int depth = 0;
-
- for_each_sched_entity(se)
- depth++;
-
- return depth;
-}
-
static void
find_matching_se(struct sched_entity **se, struct sched_entity **pse)
{
*/
/* First walk up until both entities are at same depth */
- se_depth = depth_se(*se);
- pse_depth = depth_se(*pse);
+ se_depth = (*se)->depth;
+ pse_depth = (*pse)->depth;
while (se_depth > pse_depth) {
se_depth--;
#define for_each_leaf_cfs_rq(rq, cfs_rq) \
for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
-static inline int
-is_same_group(struct sched_entity *se, struct sched_entity *pse)
-{
- return 1;
-}
-
static inline struct sched_entity *parent_entity(struct sched_entity *se)
{
return NULL;
/* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */
unsigned int sysctl_numa_balancing_scan_delay = 1000;
-/*
- * After skipping a page migration on a shared page, skip N more numa page
- * migrations unconditionally. This reduces the number of NUMA migrations
- * in shared memory workloads, and has the effect of pulling tasks towards
- * where their memory lives, over pulling the memory towards the task.
- */
-unsigned int sysctl_numa_balancing_migrate_deferred = 16;
-
static unsigned int task_nr_scan_windows(struct task_struct *p)
{
unsigned long rss = 0;
struct list_head task_list;
struct rcu_head rcu;
+ nodemask_t active_nodes;
unsigned long total_faults;
+ /*
+ * Faults_cpu is used to decide whether memory should move
+ * towards the CPU. As a consequence, these stats are weighted
+ * more by CPU use than by memory faults.
+ */
+ unsigned long *faults_cpu;
unsigned long faults[0];
};
+/* Shared or private faults. */
+#define NR_NUMA_HINT_FAULT_TYPES 2
+
+/* Memory and CPU locality */
+#define NR_NUMA_HINT_FAULT_STATS (NR_NUMA_HINT_FAULT_TYPES * 2)
+
+/* Averaged statistics, and temporary buffers. */
+#define NR_NUMA_HINT_FAULT_BUCKETS (NR_NUMA_HINT_FAULT_STATS * 2)
+
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)
{
- return 2 * nid + priv;
+ return NR_NUMA_HINT_FAULT_TYPES * nid + priv;
}
static inline unsigned long task_faults(struct task_struct *p, int nid)
{
- if (!p->numa_faults)
+ if (!p->numa_faults_memory)
return 0;
- return p->numa_faults[task_faults_idx(nid, 0)] +
- p->numa_faults[task_faults_idx(nid, 1)];
+ return p->numa_faults_memory[task_faults_idx(nid, 0)] +
+ p->numa_faults_memory[task_faults_idx(nid, 1)];
}
static inline unsigned long group_faults(struct task_struct *p, int nid)
p->numa_group->faults[task_faults_idx(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)];
+}
+
/*
* These return the fraction of accesses done by a particular task, or
* task group, on a particular numa node. The group weight is given a
{
unsigned long total_faults;
- if (!p->numa_faults)
+ if (!p->numa_faults_memory)
return 0;
total_faults = p->total_numa_faults;
return 1000 * group_faults(p, nid) / p->numa_group->total_faults;
}
+bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
+ int src_nid, int dst_cpu)
+{
+ struct numa_group *ng = p->numa_group;
+ int dst_nid = cpu_to_node(dst_cpu);
+ int last_cpupid, this_cpupid;
+
+ this_cpupid = cpu_pid_to_cpupid(dst_cpu, current->pid);
+
+ /*
+ * Multi-stage node selection is used in conjunction with a periodic
+ * migration fault to build a temporal task<->page relation. By using
+ * a two-stage filter we remove short/unlikely relations.
+ *
+ * Using P(p) ~ n_p / n_t as per frequentist probability, we can equate
+ * a task's usage of a particular page (n_p) per total usage of this
+ * page (n_t) (in a given time-span) to a probability.
+ *
+ * Our periodic faults will sample this probability and getting the
+ * same result twice in a row, given these samples are fully
+ * independent, is then given by P(n)^2, provided our sample period
+ * is sufficiently short compared to the usage pattern.
+ *
+ * This quadric squishes small probabilities, making it less likely we
+ * act on an unlikely task<->page relation.
+ */
+ last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
+ if (!cpupid_pid_unset(last_cpupid) &&
+ cpupid_to_nid(last_cpupid) != dst_nid)
+ return false;
+
+ /* Always allow migrate on private faults */
+ if (cpupid_match_pid(p, last_cpupid))
+ return true;
+
+ /* A shared fault, but p->numa_group has not been set up yet. */
+ if (!ng)
+ return true;
+
+ /*
+ * Do not migrate if the destination is not a node that
+ * is actively used by this numa group.
+ */
+ if (!node_isset(dst_nid, ng->active_nodes))
+ return false;
+
+ /*
+ * Source is a node that is not actively used by this
+ * numa group, while the destination is. Migrate.
+ */
+ if (!node_isset(src_nid, ng->active_nodes))
+ return true;
+
+ /*
+ * Both source and destination are nodes in active
+ * use by this numa group. Maximize memory bandwidth
+ * by migrating from more heavily used groups, to less
+ * heavily used ones, spreading the load around.
+ * Use a 1/4 hysteresis to avoid spurious page movement.
+ */
+ return group_faults(p, dst_nid) < (group_faults(p, src_nid) * 3 / 4);
+}
+
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 void numa_migrate_preferred(struct task_struct *p)
{
/* This task has no NUMA fault statistics yet */
- if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
+ if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults_memory))
return;
/* Periodically retry migrating the task to the preferred node */
task_numa_migrate(p);
}
+/*
+ * Find the nodes on which the workload is actively running. We do this by
+ * tracking the nodes from which NUMA hinting faults are triggered. This can
+ * be different from the set of nodes where the workload's memory is currently
+ * located.
+ *
+ * The bitmask is used to make smarter decisions on when to do NUMA page
+ * migrations, To prevent flip-flopping, and excessive page migrations, nodes
+ * are added when they cause over 6/16 of the maximum number of faults, but
+ * only removed when they drop below 3/16.
+ */
+static void update_numa_active_node_mask(struct numa_group *numa_group)
+{
+ unsigned long faults, max_faults = 0;
+ int nid;
+
+ for_each_online_node(nid) {
+ faults = group_faults_cpu(numa_group, nid);
+ if (faults > max_faults)
+ max_faults = faults;
+ }
+
+ for_each_online_node(nid) {
+ faults = group_faults_cpu(numa_group, nid);
+ if (!node_isset(nid, numa_group->active_nodes)) {
+ if (faults > max_faults * 6 / 16)
+ node_set(nid, numa_group->active_nodes);
+ } else if (faults < max_faults * 3 / 16)
+ node_clear(nid, numa_group->active_nodes);
+ }
+}
+
/*
* When adapting the scan rate, the period is divided into NUMA_PERIOD_SLOTS
* increments. The more local the fault statistics are, the higher the scan
memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
}
+/*
+ * Get the fraction of time the task has been running since the last
+ * NUMA placement cycle. The scheduler keeps similar statistics, but
+ * decays those on a 32ms period, which is orders of magnitude off
+ * from the dozens-of-seconds NUMA balancing period. Use the scheduler
+ * stats only if the task is so new there are no NUMA statistics yet.
+ */
+static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period)
+{
+ u64 runtime, delta, now;
+ /* Use the start of this time slice to avoid calculations. */
+ now = p->se.exec_start;
+ runtime = p->se.sum_exec_runtime;
+
+ if (p->last_task_numa_placement) {
+ delta = runtime - p->last_sum_exec_runtime;
+ *period = now - p->last_task_numa_placement;
+ } else {
+ delta = p->se.avg.runnable_avg_sum;
+ *period = p->se.avg.runnable_avg_period;
+ }
+
+ p->last_sum_exec_runtime = runtime;
+ p->last_task_numa_placement = now;
+
+ return delta;
+}
+
static void task_numa_placement(struct task_struct *p)
{
int seq, nid, max_nid = -1, max_group_nid = -1;
unsigned long max_faults = 0, max_group_faults = 0;
unsigned long fault_types[2] = { 0, 0 };
+ unsigned long total_faults;
+ u64 runtime, period;
spinlock_t *group_lock = NULL;
seq = ACCESS_ONCE(p->mm->numa_scan_seq);
p->numa_scan_seq = seq;
p->numa_scan_period_max = task_scan_max(p);
+ total_faults = p->numa_faults_locality[0] +
+ p->numa_faults_locality[1];
+ runtime = numa_get_avg_runtime(p, &period);
+
/* If the task is part of a group prevent parallel updates to group stats */
if (p->numa_group) {
group_lock = &p->numa_group->lock;
unsigned long faults = 0, group_faults = 0;
int priv, i;
- for (priv = 0; priv < 2; priv++) {
- long diff;
+ for (priv = 0; priv < NR_NUMA_HINT_FAULT_TYPES; priv++) {
+ long diff, f_diff, f_weight;
i = task_faults_idx(nid, priv);
- diff = -p->numa_faults[i];
/* Decay existing window, copy faults since last scan */
- p->numa_faults[i] >>= 1;
- p->numa_faults[i] += p->numa_faults_buffer[i];
- fault_types[priv] += p->numa_faults_buffer[i];
- p->numa_faults_buffer[i] = 0;
+ 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;
- faults += p->numa_faults[i];
- diff += p->numa_faults[i];
+ /*
+ * Normalize the faults_from, so all tasks in a group
+ * count according to CPU use, instead of by the raw
+ * number of faults. Tasks with little runtime have
+ * little over-all impact on throughput, and thus their
+ * faults are less important.
+ */
+ f_weight = div64_u64(runtime << 16, period + 1);
+ f_weight = (f_weight * p->numa_faults_buffer_cpu[i]) /
+ (total_faults + 1);
+ f_diff = f_weight - p->numa_faults_cpu[i] / 2;
+ p->numa_faults_buffer_cpu[i] = 0;
+
+ p->numa_faults_memory[i] += diff;
+ p->numa_faults_cpu[i] += f_diff;
+ faults += p->numa_faults_memory[i];
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;
p->numa_group->total_faults += diff;
group_faults += p->numa_group->faults[i];
}
update_task_scan_period(p, fault_types[0], fault_types[1]);
if (p->numa_group) {
+ update_numa_active_node_mask(p->numa_group);
/*
* If the preferred task and group nids are different,
* iterate over the nodes again to find the best place.
if (unlikely(!p->numa_group)) {
unsigned int size = sizeof(struct numa_group) +
- 2*nr_node_ids*sizeof(unsigned long);
+ 4*nr_node_ids*sizeof(unsigned long);
grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
if (!grp)
spin_lock_init(&grp->lock);
INIT_LIST_HEAD(&grp->task_list);
grp->gid = p->pid;
+ /* Second half of the array tracks nids where faults happen */
+ grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES *
+ nr_node_ids;
+
+ node_set(task_node(current), grp->active_nodes);
- for (i = 0; i < 2*nr_node_ids; i++)
- grp->faults[i] = p->numa_faults[i];
+ for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
+ grp->faults[i] = p->numa_faults_memory[i];
grp->total_faults = p->total_numa_faults;
double_lock(&my_grp->lock, &grp->lock);
- for (i = 0; i < 2*nr_node_ids; i++) {
- my_grp->faults[i] -= p->numa_faults[i];
- grp->faults[i] += p->numa_faults[i];
+ 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->total_faults -= p->total_numa_faults;
grp->total_faults += p->total_numa_faults;
{
struct numa_group *grp = p->numa_group;
int i;
- void *numa_faults = p->numa_faults;
+ void *numa_faults = p->numa_faults_memory;
if (grp) {
spin_lock(&grp->lock);
- for (i = 0; i < 2*nr_node_ids; i++)
- grp->faults[i] -= p->numa_faults[i];
+ for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
+ grp->faults[i] -= p->numa_faults_memory[i];
grp->total_faults -= p->total_numa_faults;
list_del(&p->numa_entry);
put_numa_group(grp);
}
- p->numa_faults = NULL;
- p->numa_faults_buffer = NULL;
+ p->numa_faults_memory = NULL;
+ p->numa_faults_buffer_memory = NULL;
+ p->numa_faults_cpu= NULL;
+ p->numa_faults_buffer_cpu = NULL;
kfree(numa_faults);
}
/*
* Got a PROT_NONE fault for a page on @node.
*/
-void task_numa_fault(int last_cpupid, int node, int pages, int flags)
+void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
{
struct task_struct *p = current;
bool migrated = flags & TNF_MIGRATED;
+ int cpu_node = task_node(current);
int priv;
if (!numabalancing_enabled)
return;
/* Allocate buffer to track faults on a per-node basis */
- if (unlikely(!p->numa_faults)) {
- int size = sizeof(*p->numa_faults) * 2 * nr_node_ids;
+ if (unlikely(!p->numa_faults_memory)) {
+ int size = sizeof(*p->numa_faults_memory) *
+ NR_NUMA_HINT_FAULT_BUCKETS * nr_node_ids;
- /* numa_faults and numa_faults_buffer share the allocation */
- p->numa_faults = kzalloc(size * 2, GFP_KERNEL|__GFP_NOWARN);
- if (!p->numa_faults)
+ p->numa_faults_memory = kzalloc(size, GFP_KERNEL|__GFP_NOWARN);
+ if (!p->numa_faults_memory)
return;
- BUG_ON(p->numa_faults_buffer);
- p->numa_faults_buffer = p->numa_faults + (2 * nr_node_ids);
+ 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));
}
if (migrated)
p->numa_pages_migrated += pages;
- p->numa_faults_buffer[task_faults_idx(node, priv)] += 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_locality[!!(flags & TNF_FAULT_LOCAL)] += pages;
}
update_rq_runnable_avg(this_rq, 0);
}
-#else
+#else /* CONFIG_SMP */
+
static inline void update_entity_load_avg(struct sched_entity *se,
int update_cfs_rq) {}
static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
int sleep) {}
static inline void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq,
int force_update) {}
-#endif
+#endif /* CONFIG_SMP */
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
{
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- if (cfs_rq->last == se)
- cfs_rq->last = NULL;
- else
+ if (cfs_rq->last != se)
break;
+
+ cfs_rq->last = NULL;
}
}
{
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- if (cfs_rq->next == se)
- cfs_rq->next = NULL;
- else
+ if (cfs_rq->next != se)
break;
+
+ cfs_rq->next = NULL;
}
}
{
for_each_sched_entity(se) {
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- if (cfs_rq->skip == se)
- cfs_rq->skip = NULL;
- else
+ if (cfs_rq->skip != se)
break;
+
+ cfs_rq->skip = NULL;
}
}
* 3) pick the "last" process, for cache locality
* 4) do not run the "skip" process, if something else is available
*/
-static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
+static struct sched_entity *
+pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
- struct sched_entity *se = __pick_first_entity(cfs_rq);
- struct sched_entity *left = se;
+ struct sched_entity *left = __pick_first_entity(cfs_rq);
+ struct sched_entity *se;
+
+ /*
+ * If curr is set we have to see if its left of the leftmost entity
+ * still in the tree, provided there was anything in the tree at all.
+ */
+ if (!left || (curr && entity_before(curr, left)))
+ left = curr;
+
+ se = left; /* ideally we run the leftmost entity */
/*
* Avoid running the skip buddy, if running something else can
* be done without getting too unfair.
*/
if (cfs_rq->skip == se) {
- struct sched_entity *second = __pick_next_entity(se);
+ struct sched_entity *second;
+
+ if (se == curr) {
+ second = __pick_first_entity(cfs_rq);
+ } else {
+ second = __pick_next_entity(se);
+ if (!second || (curr && entity_before(curr, second)))
+ second = curr;
+ }
+
if (second && wakeup_preempt_entity(second, left) < 1)
se = second;
}
return se;
}
-static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
+static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
{
}
/* conditionally throttle active cfs_rq's from put_prev_entity() */
-static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
if (!cfs_bandwidth_used())
- return;
+ return false;
if (likely(!cfs_rq->runtime_enabled || cfs_rq->runtime_remaining > 0))
- return;
+ return false;
/*
* it's possible for a throttled entity to be forced into a running
* state (e.g. set_curr_task), in this case we're finished.
*/
if (cfs_rq_throttled(cfs_rq))
- return;
+ return true;
throttle_cfs_rq(cfs_rq);
+ return true;
}
static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
}
static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) {}
-static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
+static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq) { return false; }
static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
set_last_buddy(se);
}
-static struct task_struct *pick_next_task_fair(struct rq *rq)
+static struct task_struct *
+pick_next_task_fair(struct rq *rq, struct task_struct *prev)
{
- struct task_struct *p;
struct cfs_rq *cfs_rq = &rq->cfs;
struct sched_entity *se;
+ struct task_struct *p;
+again: __maybe_unused
+#ifdef CONFIG_FAIR_GROUP_SCHED
if (!cfs_rq->nr_running)
- return NULL;
+ goto idle;
+
+ if (!prev || prev->sched_class != &fair_sched_class)
+ goto simple;
+
+ /*
+ * Because of the set_next_buddy() in dequeue_task_fair() it is rather
+ * likely that a next task is from the same cgroup as the current.
+ *
+ * Therefore attempt to avoid putting and setting the entire cgroup
+ * hierarchy, only change the part that actually changes.
+ */
do {
- se = pick_next_entity(cfs_rq);
+ struct sched_entity *curr = cfs_rq->curr;
+
+ /*
+ * Since we got here without doing put_prev_entity() we also
+ * have to consider cfs_rq->curr. If it is still a runnable
+ * entity, update_curr() will update its vruntime, otherwise
+ * forget we've ever seen it.
+ */
+ if (curr && curr->on_rq)
+ update_curr(cfs_rq);
+ else
+ curr = NULL;
+
+ /*
+ * This call to check_cfs_rq_runtime() will do the throttle and
+ * dequeue its entity in the parent(s). Therefore the 'simple'
+ * nr_running test will indeed be correct.
+ */
+ if (unlikely(check_cfs_rq_runtime(cfs_rq)))
+ goto simple;
+
+ se = pick_next_entity(cfs_rq, curr);
+ cfs_rq = group_cfs_rq(se);
+ } while (cfs_rq);
+
+ p = task_of(se);
+
+ /*
+ * Since we haven't yet done put_prev_entity and if the selected task
+ * is a different task than we started out with, try and touch the
+ * least amount of cfs_rqs.
+ */
+ if (prev != p) {
+ struct sched_entity *pse = &prev->se;
+
+ while (!(cfs_rq = is_same_group(se, pse))) {
+ int se_depth = se->depth;
+ int pse_depth = pse->depth;
+
+ if (se_depth <= pse_depth) {
+ put_prev_entity(cfs_rq_of(pse), pse);
+ pse = parent_entity(pse);
+ }
+ if (se_depth >= pse_depth) {
+ set_next_entity(cfs_rq_of(se), se);
+ se = parent_entity(se);
+ }
+ }
+
+ put_prev_entity(cfs_rq, pse);
+ set_next_entity(cfs_rq, se);
+ }
+
+ if (hrtick_enabled(rq))
+ hrtick_start_fair(rq, p);
+
+ return p;
+simple:
+ cfs_rq = &rq->cfs;
+#endif
+
+ if (!cfs_rq->nr_running)
+ goto idle;
+
+ if (prev)
+ prev->sched_class->put_prev_task(rq, prev);
+
+ do {
+ se = pick_next_entity(cfs_rq, NULL);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);
p = task_of(se);
+
if (hrtick_enabled(rq))
hrtick_start_fair(rq, p);
return p;
+
+idle:
+#ifdef CONFIG_SMP
+ idle_enter_fair(rq);
+ /*
+ * We must set idle_stamp _before_ calling idle_balance(), such that we
+ * measure the duration of idle_balance() as idle time.
+ */
+ rq->idle_stamp = rq_clock(rq);
+ if (idle_balance(rq)) { /* drops rq->lock */
+ rq->idle_stamp = 0;
+ goto again;
+ }
+#endif
+
+ return NULL;
}
/*
{
int src_nid, dst_nid;
- if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults ||
+ if (!sched_feat(NUMA_FAVOUR_HIGHER) || !p->numa_faults_memory ||
!(env->sd->flags & SD_NUMA)) {
return false;
}
if (!sched_feat(NUMA) || !sched_feat(NUMA_RESIST_LOWER))
return false;
- if (!p->numa_faults || !(env->sd->flags & SD_NUMA))
+ if (!p->numa_faults_memory || !(env->sd->flags & SD_NUMA))
return false;
src_nid = cpu_to_node(env->src_cpu);
* idle_balance is called by schedule() if this_cpu is about to become
* idle. Attempts to pull tasks from other CPUs.
*/
-void idle_balance(int this_cpu, struct rq *this_rq)
+int idle_balance(struct rq *this_rq)
{
struct sched_domain *sd;
int pulled_task = 0;
unsigned long next_balance = jiffies + HZ;
u64 curr_cost = 0;
-
- this_rq->idle_stamp = rq_clock(this_rq);
+ int this_cpu = this_rq->cpu;
if (this_rq->avg_idle < sysctl_sched_migration_cost)
- return;
+ return 0;
/*
* Drop the rq->lock, but keep IRQ/preempt disabled.
interval = msecs_to_jiffies(sd->balance_interval);
if (time_after(next_balance, sd->last_balance + interval))
next_balance = sd->last_balance + interval;
- if (pulled_task) {
- this_rq->idle_stamp = 0;
+ if (pulled_task)
break;
- }
}
rcu_read_unlock();
raw_spin_lock(&this_rq->lock);
+ /*
+ * While browsing the domains, we released the rq lock.
+ * A task could have be enqueued in the meantime
+ */
+ if (this_rq->nr_running && !pulled_task)
+ return 1;
+
if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
/*
* We are going idle. next_balance may be set based on
if (curr_cost > this_rq->max_idle_balance_cost)
this_rq->max_idle_balance_cost = curr_cost;
+
+ return pulled_task;
}
/*
#ifdef CONFIG_FAIR_GROUP_SCHED
static void task_move_group_fair(struct task_struct *p, int on_rq)
{
+ struct sched_entity *se = &p->se;
struct cfs_rq *cfs_rq;
+
/*
* If the task was not on the rq at the time of this cgroup movement
* it must have been asleep, sleeping tasks keep their ->vruntime
* To prevent boost or penalty in the new cfs_rq caused by delta
* min_vruntime between the two cfs_rqs, we skip vruntime adjustment.
*/
- if (!on_rq && (!p->se.sum_exec_runtime || p->state == TASK_WAKING))
+ if (!on_rq && (!se->sum_exec_runtime || p->state == TASK_WAKING))
on_rq = 1;
if (!on_rq)
- p->se.vruntime -= cfs_rq_of(&p->se)->min_vruntime;
+ se->vruntime -= cfs_rq_of(se)->min_vruntime;
set_task_rq(p, task_cpu(p));
+ se->depth = se->parent ? se->parent->depth + 1 : 0;
if (!on_rq) {
- cfs_rq = cfs_rq_of(&p->se);
- p->se.vruntime += cfs_rq->min_vruntime;
+ cfs_rq = cfs_rq_of(se);
+ se->vruntime += cfs_rq->min_vruntime;
#ifdef CONFIG_SMP
/*
* migrate_task_rq_fair() will have removed our previous
* contribution, but we must synchronize for ongoing future
* decay.
*/
- p->se.avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
- cfs_rq->blocked_load_avg += p->se.avg.load_avg_contrib;
+ se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
+ cfs_rq->blocked_load_avg += se->avg.load_avg_contrib;
#endif
}
}
if (!se)
return;
- if (!parent)
+ if (!parent) {
se->cfs_rq = &rq->cfs;
- else
+ se->depth = 0;
+ } else {
se->cfs_rq = parent->my_q;
+ se->depth = parent->depth + 1;
+ }
se->my_q = cfs_rq;
/* guarantee group entities always have weight */
--- /dev/null
+/*
+ * Generic entry point for the idle threads
+ */
+#include <linux/sched.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/tick.h>
+#include <linux/mm.h>
+#include <linux/stackprotector.h>
+
+#include <asm/tlb.h>
+
+#include <trace/events/power.h>
+
+static int __read_mostly cpu_idle_force_poll;
+
+void cpu_idle_poll_ctrl(bool enable)
+{
+ if (enable) {
+ cpu_idle_force_poll++;
+ } else {
+ cpu_idle_force_poll--;
+ WARN_ON_ONCE(cpu_idle_force_poll < 0);
+ }
+}
+
+#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP
+static int __init cpu_idle_poll_setup(char *__unused)
+{
+ cpu_idle_force_poll = 1;
+ return 1;
+}
+__setup("nohlt", cpu_idle_poll_setup);
+
+static int __init cpu_idle_nopoll_setup(char *__unused)
+{
+ cpu_idle_force_poll = 0;
+ return 1;
+}
+__setup("hlt", cpu_idle_nopoll_setup);
+#endif
+
+static inline int cpu_idle_poll(void)
+{
+ rcu_idle_enter();
+ trace_cpu_idle_rcuidle(0, smp_processor_id());
+ local_irq_enable();
+ while (!tif_need_resched())
+ cpu_relax();
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+ rcu_idle_exit();
+ return 1;
+}
+
+/* Weak implementations for optional arch specific functions */
+void __weak arch_cpu_idle_prepare(void) { }
+void __weak arch_cpu_idle_enter(void) { }
+void __weak arch_cpu_idle_exit(void) { }
+void __weak arch_cpu_idle_dead(void) { }
+void __weak arch_cpu_idle(void)
+{
+ cpu_idle_force_poll = 1;
+ local_irq_enable();
+}
+
+/*
+ * Generic idle loop implementation
+ */
+static void cpu_idle_loop(void)
+{
+ while (1) {
+ tick_nohz_idle_enter();
+
+ while (!need_resched()) {
+ check_pgt_cache();
+ rmb();
+
+ if (cpu_is_offline(smp_processor_id()))
+ arch_cpu_idle_dead();
+
+ local_irq_disable();
+ arch_cpu_idle_enter();
+
+ /*
+ * In poll mode we reenable interrupts and spin.
+ *
+ * Also if we detected in the wakeup from idle
+ * path that the tick broadcast device expired
+ * for us, we don't want to go deep idle as we
+ * know that the IPI is going to arrive right
+ * away
+ */
+ if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
+ cpu_idle_poll();
+ } else {
+ if (!current_clr_polling_and_test()) {
+ stop_critical_timings();
+ rcu_idle_enter();
+ if (cpuidle_idle_call())
+ arch_cpu_idle();
+ if (WARN_ON_ONCE(irqs_disabled()))
+ local_irq_enable();
+ rcu_idle_exit();
+ start_critical_timings();
+ } else {
+ local_irq_enable();
+ }
+ __current_set_polling();
+ }
+ arch_cpu_idle_exit();
+ /*
+ * We need to test and propagate the TIF_NEED_RESCHED
+ * bit here because we might not have send the
+ * reschedule IPI to idle tasks.
+ */
+ if (tif_need_resched())
+ set_preempt_need_resched();
+ }
+ tick_nohz_idle_exit();
+ schedule_preempt_disabled();
+ }
+}
+
+void cpu_startup_entry(enum cpuhp_state state)
+{
+ /*
+ * This #ifdef needs to die, but it's too late in the cycle to
+ * make this generic (arm and sh have never invoked the canary
+ * init for the non boot cpus!). Will be fixed in 3.11
+ */
+#ifdef CONFIG_X86
+ /*
+ * If we're the non-boot CPU, nothing set the stack canary up
+ * for us. The boot CPU already has it initialized but no harm
+ * in doing it again. This is a good place for updating it, as
+ * we wont ever return from this function (so the invalid
+ * canaries already on the stack wont ever trigger).
+ */
+ boot_init_stack_canary();
+#endif
+ __current_set_polling();
+ arch_cpu_idle_prepare();
+ cpu_idle_loop();
+}
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
-
-static void pre_schedule_idle(struct rq *rq, struct task_struct *prev)
-{
- idle_exit_fair(rq);
- rq_last_tick_reset(rq);
-}
-
-static void post_schedule_idle(struct rq *rq)
-{
- idle_enter_fair(rq);
-}
#endif /* CONFIG_SMP */
+
/*
* Idle tasks are unconditionally rescheduled:
*/
resched_task(rq->idle);
}
-static struct task_struct *pick_next_task_idle(struct rq *rq)
+static struct task_struct *
+pick_next_task_idle(struct rq *rq, struct task_struct *prev)
{
+ if (prev)
+ prev->sched_class->put_prev_task(rq, prev);
+
schedstat_inc(rq, sched_goidle);
#ifdef CONFIG_SMP
- /* Trigger the post schedule to do an idle_enter for CFS */
- rq->post_schedule = 1;
+ idle_enter_fair(rq);
#endif
return rq->idle;
}
static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
{
+#ifdef CONFIG_SMP
+ idle_exit_fair(rq);
+ rq_last_tick_reset(rq);
+#endif
}
static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_idle,
- .pre_schedule = pre_schedule_idle,
- .post_schedule = post_schedule_idle,
#endif
.set_curr_task = set_curr_task_idle,
#ifdef CONFIG_SMP
+static int pull_rt_task(struct rq *this_rq);
+
static inline int rt_overloaded(struct rq *rq)
{
return atomic_read(&rq->rd->rto_count);
{
struct sched_rt_entity *rt_se;
struct task_struct *p;
- struct rt_rq *rt_rq;
-
- rt_rq = &rq->rt;
-
- if (!rt_rq->rt_nr_running)
- return NULL;
-
- if (rt_rq_throttled(rt_rq))
- return NULL;
+ struct rt_rq *rt_rq = &rq->rt;
do {
rt_se = pick_next_rt_entity(rq, rt_rq);
return p;
}
-static struct task_struct *pick_next_task_rt(struct rq *rq)
+static struct task_struct *
+pick_next_task_rt(struct rq *rq, struct task_struct *prev)
{
- struct task_struct *p = _pick_next_task_rt(rq);
+ struct task_struct *p;
+ struct rt_rq *rt_rq = &rq->rt;
+
+#ifdef CONFIG_SMP
+ /* Try to pull RT tasks here if we lower this rq's prio */
+ if (rq->rt.highest_prio.curr > prev->prio)
+ pull_rt_task(rq);
+#endif
+
+ if (!rt_rq->rt_nr_running)
+ return NULL;
+
+ if (rt_rq_throttled(rt_rq))
+ return NULL;
+
+ if (prev)
+ prev->sched_class->put_prev_task(rq, prev);
+
+ p = _pick_next_task_rt(rq);
/* The running task is never eligible for pushing */
if (p)
return ret;
}
-static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
-{
- /* Try to pull RT tasks here if we lower this rq's prio */
- if (rq->rt.highest_prio.curr > prev->prio)
- pull_rt_task(rq);
-}
-
static void post_schedule_rt(struct rq *rq)
{
push_rt_tasks(rq);
.set_cpus_allowed = set_cpus_allowed_rt,
.rq_online = rq_online_rt,
.rq_offline = rq_offline_rt,
- .pre_schedule = pre_schedule_rt,
.post_schedule = post_schedule_rt,
.task_woken = task_woken_rt,
.switched_from = switched_from_rt,
extern long calc_load_fold_active(struct rq *this_rq);
extern void update_cpu_load_active(struct rq *this_rq);
-/*
- * Convert user-nice values [ -20 ... 0 ... 19 ]
- * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
- * and back.
- */
-#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
-#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
-#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
-
-/*
- * 'User priority' is the nice value converted to something we
- * can work with better when scaling various scheduler parameters,
- * it's a [ 0 ... 39 ] range.
- */
-#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
-#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
-#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
-
/*
* Helpers for converting nanosecond timing to jiffy resolution
*/
void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
- struct task_struct * (*pick_next_task) (struct rq *rq);
+ /*
+ * It is the responsibility of the pick_next_task() method that will
+ * return the next task to call put_prev_task() on the @prev task or
+ * something equivalent.
+ */
+ struct task_struct * (*pick_next_task) (struct rq *rq,
+ struct task_struct *prev);
void (*put_prev_task) (struct rq *rq, struct task_struct *p);
#ifdef CONFIG_SMP
int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
- void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
void (*post_schedule) (struct rq *this_rq);
void (*task_waking) (struct task_struct *task);
void (*task_woken) (struct rq *this_rq, struct task_struct *task);
extern void update_group_power(struct sched_domain *sd, int cpu);
extern void trigger_load_balance(struct rq *rq);
-extern void idle_balance(int this_cpu, struct rq *this_rq);
+extern int idle_balance(struct rq *this_rq);
extern void idle_enter_fair(struct rq *this_rq);
extern void idle_exit_fair(struct rq *this_rq);
/* we're never preempted */
}
-static struct task_struct *pick_next_task_stop(struct rq *rq)
+static struct task_struct *
+pick_next_task_stop(struct rq *rq, struct task_struct *prev)
{
struct task_struct *stop = rq->stop;
- if (stop && stop->on_rq) {
- stop->se.exec_start = rq_clock_task(rq);
- return stop;
- }
+ if (!stop || !stop->on_rq)
+ return NULL;
- return NULL;
+ if (prev)
+ prev->sched_class->put_prev_task(rq, prev);
+
+ stop->se.exec_start = rq_clock_task(rq);
+
+ return stop;
}
static void
.mode = 0644,
.proc_handler = proc_dointvec,
},
- {
- .procname = "numa_balancing_migrate_deferred",
- .data = &sysctl_numa_balancing_migrate_deferred,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = proc_dointvec,
- },
{
.procname = "numa_balancing",
.data = NULL, /* filled in by handler */
kmem_cache_free(sn_cache, n);
}
-#ifdef CONFIG_NUMA_BALANCING
-static bool numa_migrate_deferred(struct task_struct *p, int last_cpupid)
-{
- /* Never defer a private fault */
- if (cpupid_match_pid(p, last_cpupid))
- return false;
-
- if (p->numa_migrate_deferred) {
- p->numa_migrate_deferred--;
- return true;
- }
- return false;
-}
-
-static inline void defer_numa_migrate(struct task_struct *p)
-{
- p->numa_migrate_deferred = sysctl_numa_balancing_migrate_deferred;
-}
-#else
-static inline bool numa_migrate_deferred(struct task_struct *p, int last_cpupid)
-{
- return false;
-}
-
-static inline void defer_numa_migrate(struct task_struct *p)
-{
-}
-#endif /* CONFIG_NUMA_BALANCING */
-
/**
* mpol_misplaced - check whether current page node is valid in policy
*
/* Migrate the page towards the node whose CPU is referencing it */
if (pol->flags & MPOL_F_MORON) {
- int last_cpupid;
- int this_cpupid;
-
polnid = thisnid;
- this_cpupid = cpu_pid_to_cpupid(thiscpu, current->pid);
-
- /*
- * Multi-stage node selection is used in conjunction
- * with a periodic migration fault to build a temporal
- * task<->page relation. By using a two-stage filter we
- * remove short/unlikely relations.
- *
- * Using P(p) ~ n_p / n_t as per frequentist
- * probability, we can equate a task's usage of a
- * particular page (n_p) per total usage of this
- * page (n_t) (in a given time-span) to a probability.
- *
- * Our periodic faults will sample this probability and
- * getting the same result twice in a row, given these
- * samples are fully independent, is then given by
- * P(n)^2, provided our sample period is sufficiently
- * short compared to the usage pattern.
- *
- * This quadric squishes small probabilities, making
- * it less likely we act on an unlikely task<->page
- * relation.
- */
- last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
- if (!cpupid_pid_unset(last_cpupid) && cpupid_to_nid(last_cpupid) != thisnid) {
- /* See sysctl_numa_balancing_migrate_deferred comment */
- if (!cpupid_match_pid(current, last_cpupid))
- defer_numa_migrate(current);
-
- goto out;
- }
-
- /*
- * The quadratic filter above reduces extraneous migration
- * of shared pages somewhat. This code reduces it even more,
- * reducing the overhead of page migrations of shared pages.
- * This makes workloads with shared pages rely more on
- * "move task near its memory", and less on "move memory
- * towards its task", which is exactly what we want.
- */
- if (numa_migrate_deferred(current, last_cpupid))
+ if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
goto out;
}
projects / mirror_ubuntu-artful-kernel.git / commitdiff