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authorTony Lindgren <[email protected]>2016-03-30 10:36:06 -0700
committerTony Lindgren <[email protected]>2016-03-30 10:36:06 -0700
commit1809de7e7d37c585e01a1bcc583ea92b78fc759d (patch)
tree76c5b35c2b04eafce86a1a729c02ab705eba44bc /kernel/sched
parentebf24414809200915b9ddf7f109bba7c278c8210 (diff)
parent3ca4a238106dedc285193ee47f494a6584b6fd2f (diff)
Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes
ARM: OMAP2+: first hwmod fix for v4.6-rc Fix a longstanding bug in the hwmod code that could cause hardware SYSCONFIG register values to not match the kernel's idea of what they should be, and that could result in lower performance during IP block idle entry. Basic build, boot, and PM test logs are available here: http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/Makefile7
-rw-r--r--kernel/sched/clock.c5
-rw-r--r--kernel/sched/core.c557
-rw-r--r--kernel/sched/cpuacct.c37
-rw-r--r--kernel/sched/cpuacct.h4
-rw-r--r--kernel/sched/cpufreq.c37
-rw-r--r--kernel/sched/cputime.c53
-rw-r--r--kernel/sched/deadline.c66
-rw-r--r--kernel/sched/debug.c415
-rw-r--r--kernel/sched/fair.c392
-rw-r--r--kernel/sched/idle.c11
-rw-r--r--kernel/sched/rt.c116
-rw-r--r--kernel/sched/sched.h162
-rw-r--r--kernel/sched/stats.h8
-rw-r--r--kernel/sched/swait.c123
15 files changed, 1255 insertions, 738 deletions
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 67687973ce80..414d9c16da42 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -2,6 +2,10 @@ ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE)
endif
+# These files are disabled because they produce non-interesting flaky coverage
+# that is not a function of syscall inputs. E.g. involuntary context switches.
+KCOV_INSTRUMENT := n
+
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <[email protected]>, the -fno-omit-frame-pointer is
# needed for x86 only. Why this used to be enabled for all architectures is beyond
@@ -13,9 +17,10 @@ endif
obj-y += core.o loadavg.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 idle.o
+obj-y += wait.o swait.o completion.o idle.o
obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
+obj-$(CONFIG_CPU_FREQ) += cpufreq.o
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index bc54e84675da..fedb967a9841 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -61,6 +61,7 @@
#include <linux/static_key.h>
#include <linux/workqueue.h>
#include <linux/compiler.h>
+#include <linux/tick.h>
/*
* Scheduler clock - returns current time in nanosec units.
@@ -89,6 +90,8 @@ static void __set_sched_clock_stable(void)
{
if (!sched_clock_stable())
static_key_slow_inc(&__sched_clock_stable);
+
+ tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE);
}
void set_sched_clock_stable(void)
@@ -108,6 +111,8 @@ static void __clear_sched_clock_stable(struct work_struct *work)
/* XXX worry about clock continuity */
if (sched_clock_stable())
static_key_slow_dec(&__sched_clock_stable);
+
+ tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE);
}
static DECLARE_WORK(sched_clock_work, __clear_sched_clock_stable);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 63d3a24e081a..d8465eeab8b3 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -26,6 +26,7 @@
* Thomas Gleixner, Mike Kravetz
*/
+#include <linux/kasan.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/nmi.h>
@@ -66,14 +67,13 @@
#include <linux/pagemap.h>
#include <linux/hrtimer.h>
#include <linux/tick.h>
-#include <linux/debugfs.h>
#include <linux/ctype.h>
#include <linux/ftrace.h>
#include <linux/slab.h>
#include <linux/init_task.h>
-#include <linux/binfmts.h>
#include <linux/context_tracking.h>
#include <linux/compiler.h>
+#include <linux/frame.h>
#include <asm/switch_to.h>
#include <asm/tlb.h>
@@ -124,138 +124,6 @@ const_debug unsigned int sysctl_sched_features =
#undef SCHED_FEAT
-#ifdef CONFIG_SCHED_DEBUG
-#define SCHED_FEAT(name, enabled) \
- #name ,
-
-static const char * const sched_feat_names[] = {
-#include "features.h"
-};
-
-#undef SCHED_FEAT
-
-static int sched_feat_show(struct seq_file *m, void *v)
-{
- int i;
-
- for (i = 0; i < __SCHED_FEAT_NR; i++) {
- if (!(sysctl_sched_features & (1UL << i)))
- seq_puts(m, "NO_");
- seq_printf(m, "%s ", sched_feat_names[i]);
- }
- seq_puts(m, "\n");
-
- return 0;
-}
-
-#ifdef HAVE_JUMP_LABEL
-
-#define jump_label_key__true STATIC_KEY_INIT_TRUE
-#define jump_label_key__false STATIC_KEY_INIT_FALSE
-
-#define SCHED_FEAT(name, enabled) \
- jump_label_key__##enabled ,
-
-struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
-#include "features.h"
-};
-
-#undef SCHED_FEAT
-
-static void sched_feat_disable(int i)
-{
- static_key_disable(&sched_feat_keys[i]);
-}
-
-static void sched_feat_enable(int i)
-{
- static_key_enable(&sched_feat_keys[i]);
-}
-#else
-static void sched_feat_disable(int i) { };
-static void sched_feat_enable(int i) { };
-#endif /* HAVE_JUMP_LABEL */
-
-static int sched_feat_set(char *cmp)
-{
- int i;
- int neg = 0;
-
- if (strncmp(cmp, "NO_", 3) == 0) {
- neg = 1;
- cmp += 3;
- }
-
- for (i = 0; i < __SCHED_FEAT_NR; i++) {
- if (strcmp(cmp, sched_feat_names[i]) == 0) {
- if (neg) {
- sysctl_sched_features &= ~(1UL << i);
- sched_feat_disable(i);
- } else {
- sysctl_sched_features |= (1UL << i);
- sched_feat_enable(i);
- }
- break;
- }
- }
-
- return i;
-}
-
-static ssize_t
-sched_feat_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[64];
- char *cmp;
- int i;
- struct inode *inode;
-
- if (cnt > 63)
- cnt = 63;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- buf[cnt] = 0;
- cmp = strstrip(buf);
-
- /* Ensure the static_key remains in a consistent state */
- inode = file_inode(filp);
- inode_lock(inode);
- i = sched_feat_set(cmp);
- inode_unlock(inode);
- if (i == __SCHED_FEAT_NR)
- return -EINVAL;
-
- *ppos += cnt;
-
- return cnt;
-}
-
-static int sched_feat_open(struct inode *inode, struct file *filp)
-{
- return single_open(filp, sched_feat_show, NULL);
-}
-
-static const struct file_operations sched_feat_fops = {
- .open = sched_feat_open,
- .write = sched_feat_write,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-
-static __init int sched_init_debug(void)
-{
- debugfs_create_file("sched_features", 0644, NULL, NULL,
- &sched_feat_fops);
-
- return 0;
-}
-late_initcall(sched_init_debug);
-#endif /* CONFIG_SCHED_DEBUG */
-
/*
* Number of tasks to iterate in a single balance run.
* Limited because this is done with IRQs disabled.
@@ -453,20 +321,6 @@ static inline void init_hrtick(void)
}
#endif /* CONFIG_SCHED_HRTICK */
-/*
- * cmpxchg based fetch_or, macro so it works for different integer types
- */
-#define fetch_or(ptr, val) \
-({ typeof(*(ptr)) __old, __val = *(ptr); \
- for (;;) { \
- __old = cmpxchg((ptr), __val, __val | (val)); \
- if (__old == __val) \
- break; \
- __val = __old; \
- } \
- __old; \
-})
-
#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
/*
* Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
@@ -715,31 +569,36 @@ static inline bool got_nohz_idle_kick(void)
#endif /* CONFIG_NO_HZ_COMMON */
#ifdef CONFIG_NO_HZ_FULL
-bool sched_can_stop_tick(void)
+bool sched_can_stop_tick(struct rq *rq)
{
+ int fifo_nr_running;
+
+ /* Deadline tasks, even if single, need the tick */
+ if (rq->dl.dl_nr_running)
+ return false;
+
/*
- * FIFO realtime policy runs the highest priority task. Other runnable
- * tasks are of a lower priority. The scheduler tick does nothing.
+ * FIFO realtime policy runs the highest priority task (after DEADLINE).
+ * Other runnable tasks are of a lower priority. The scheduler tick
+ * isn't needed.
*/
- if (current->policy == SCHED_FIFO)
+ fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
+ if (fifo_nr_running)
return true;
/*
* Round-robin realtime tasks time slice with other tasks at the same
- * realtime priority. Is this task the only one at this priority?
+ * realtime priority.
*/
- if (current->policy == SCHED_RR) {
- struct sched_rt_entity *rt_se = &current->rt;
-
- return list_is_singular(&rt_se->run_list);
+ if (rq->rt.rr_nr_running) {
+ if (rq->rt.rr_nr_running == 1)
+ return true;
+ else
+ return false;
}
- /*
- * More than one running task need preemption.
- * nr_running update is assumed to be visible
- * after IPI is sent from wakers.
- */
- if (this_rq()->nr_running > 1)
+ /* Normal multitasking need periodic preemption checks */
+ if (rq->cfs.nr_running > 1)
return false;
return true;
@@ -2093,7 +1952,8 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
ttwu_queue(p, cpu);
stat:
- ttwu_stat(p, cpu, wake_flags);
+ if (schedstat_enabled())
+ ttwu_stat(p, cpu, wake_flags);
out:
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
@@ -2141,7 +2001,8 @@ static void try_to_wake_up_local(struct task_struct *p)
ttwu_activate(rq, p, ENQUEUE_WAKEUP);
ttwu_do_wakeup(rq, p, 0);
- ttwu_stat(p, smp_processor_id(), 0);
+ if (schedstat_enabled())
+ ttwu_stat(p, smp_processor_id(), 0);
out:
raw_spin_unlock(&p->pi_lock);
}
@@ -2183,7 +2044,6 @@ void __dl_clear_params(struct task_struct *p)
dl_se->dl_bw = 0;
dl_se->dl_throttled = 0;
- dl_se->dl_new = 1;
dl_se->dl_yielded = 0;
}
@@ -2210,6 +2070,7 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
#endif
#ifdef CONFIG_SCHEDSTATS
+ /* Even if schedstat is disabled, there should not be garbage */
memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
@@ -2218,6 +2079,10 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
__dl_clear_params(p);
INIT_LIST_HEAD(&p->rt.run_list);
+ p->rt.timeout = 0;
+ p->rt.time_slice = sched_rr_timeslice;
+ p->rt.on_rq = 0;
+ p->rt.on_list = 0;
#ifdef CONFIG_PREEMPT_NOTIFIERS
INIT_HLIST_HEAD(&p->preempt_notifiers);
@@ -2281,6 +2146,69 @@ int sysctl_numa_balancing(struct ctl_table *table, int write,
#endif
#endif
+DEFINE_STATIC_KEY_FALSE(sched_schedstats);
+
+#ifdef CONFIG_SCHEDSTATS
+static void set_schedstats(bool enabled)
+{
+ if (enabled)
+ static_branch_enable(&sched_schedstats);
+ else
+ static_branch_disable(&sched_schedstats);
+}
+
+void force_schedstat_enabled(void)
+{
+ if (!schedstat_enabled()) {
+ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n");
+ static_branch_enable(&sched_schedstats);
+ }
+}
+
+static int __init setup_schedstats(char *str)
+{
+ int ret = 0;
+ if (!str)
+ goto out;
+
+ if (!strcmp(str, "enable")) {
+ set_schedstats(true);
+ ret = 1;
+ } else if (!strcmp(str, "disable")) {
+ set_schedstats(false);
+ ret = 1;
+ }
+out:
+ if (!ret)
+ pr_warn("Unable to parse schedstats=\n");
+
+ return ret;
+}
+__setup("schedstats=", setup_schedstats);
+
+#ifdef CONFIG_PROC_SYSCTL
+int sysctl_schedstats(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct ctl_table t;
+ int err;
+ int state = static_branch_likely(&sched_schedstats);
+
+ if (write && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ t = *table;
+ t.data = &state;
+ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
+ if (err < 0)
+ return err;
+ if (write)
+ set_schedstats(state);
+ return err;
+}
+#endif
+#endif
+
/*
* fork()/clone()-time setup:
*/
@@ -2762,7 +2690,7 @@ asmlinkage __visible void schedule_tail(struct task_struct *prev)
/*
* context_switch - switch to the new MM and the new thread's register state.
*/
-static inline struct rq *
+static __always_inline struct rq *
context_switch(struct rq *rq, struct task_struct *prev,
struct task_struct *next)
{
@@ -3010,16 +2938,6 @@ u64 scheduler_tick_max_deferment(void)
}
#endif
-notrace unsigned long get_parent_ip(unsigned long addr)
-{
- if (in_lock_functions(addr)) {
- addr = CALLER_ADDR2;
- if (in_lock_functions(addr))
- addr = CALLER_ADDR3;
- }
- return addr;
-}
-
#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
defined(CONFIG_PREEMPT_TRACER))
@@ -3041,7 +2959,7 @@ void preempt_count_add(int val)
PREEMPT_MASK - 10);
#endif
if (preempt_count() == val) {
- unsigned long ip = get_parent_ip(CALLER_ADDR1);
+ unsigned long ip = get_lock_parent_ip();
#ifdef CONFIG_DEBUG_PREEMPT
current->preempt_disable_ip = ip;
#endif
@@ -3068,7 +2986,7 @@ void preempt_count_sub(int val)
#endif
if (preempt_count() == val)
- trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
__preempt_count_sub(val);
}
EXPORT_SYMBOL(preempt_count_sub);
@@ -3257,7 +3175,7 @@ static void __sched notrace __schedule(bool preempt)
if (prev->flags & PF_WQ_WORKER) {
struct task_struct *to_wakeup;
- to_wakeup = wq_worker_sleeping(prev, cpu);
+ to_wakeup = wq_worker_sleeping(prev);
if (to_wakeup)
try_to_wake_up_local(to_wakeup);
}
@@ -3280,7 +3198,6 @@ static void __sched notrace __schedule(bool preempt)
trace_sched_switch(preempt, prev, next);
rq = context_switch(rq, prev, next); /* unlocks the rq */
- cpu = cpu_of(rq);
} else {
lockdep_unpin_lock(&rq->lock);
raw_spin_unlock_irq(&rq->lock);
@@ -3288,6 +3205,7 @@ static void __sched notrace __schedule(bool preempt)
balance_callback(rq);
}
+STACK_FRAME_NON_STANDARD(__schedule); /* switch_to() */
static inline void sched_submit_work(struct task_struct *tsk)
{
@@ -3466,7 +3384,7 @@ EXPORT_SYMBOL(default_wake_function);
*/
void rt_mutex_setprio(struct task_struct *p, int prio)
{
- int oldprio, queued, running, enqueue_flag = ENQUEUE_RESTORE;
+ int oldprio, queued, running, queue_flag = DEQUEUE_SAVE | DEQUEUE_MOVE;
struct rq *rq;
const struct sched_class *prev_class;
@@ -3494,11 +3412,15 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
trace_sched_pi_setprio(p, prio);
oldprio = p->prio;
+
+ if (oldprio == prio)
+ queue_flag &= ~DEQUEUE_MOVE;
+
prev_class = p->sched_class;
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
- dequeue_task(rq, p, DEQUEUE_SAVE);
+ dequeue_task(rq, p, queue_flag);
if (running)
put_prev_task(rq, p);
@@ -3516,7 +3438,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (!dl_prio(p->normal_prio) ||
(pi_task && dl_entity_preempt(&pi_task->dl, &p->dl))) {
p->dl.dl_boosted = 1;
- enqueue_flag |= ENQUEUE_REPLENISH;
+ queue_flag |= ENQUEUE_REPLENISH;
} else
p->dl.dl_boosted = 0;
p->sched_class = &dl_sched_class;
@@ -3524,7 +3446,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (dl_prio(oldprio))
p->dl.dl_boosted = 0;
if (oldprio < prio)
- enqueue_flag |= ENQUEUE_HEAD;
+ queue_flag |= ENQUEUE_HEAD;
p->sched_class = &rt_sched_class;
} else {
if (dl_prio(oldprio))
@@ -3539,7 +3461,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
if (running)
p->sched_class->set_curr_task(rq);
if (queued)
- enqueue_task(rq, p, enqueue_flag);
+ enqueue_task(rq, p, queue_flag);
check_class_changed(rq, p, prev_class, oldprio);
out_unlock:
@@ -3895,6 +3817,7 @@ static int __sched_setscheduler(struct task_struct *p,
const struct sched_class *prev_class;
struct rq *rq;
int reset_on_fork;
+ int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
@@ -4077,17 +4000,14 @@ change:
* itself.
*/
new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
- if (new_effective_prio == oldprio) {
- __setscheduler_params(p, attr);
- task_rq_unlock(rq, p, &flags);
- return 0;
- }
+ if (new_effective_prio == oldprio)
+ queue_flags &= ~DEQUEUE_MOVE;
}
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
- dequeue_task(rq, p, DEQUEUE_SAVE);
+ dequeue_task(rq, p, queue_flags);
if (running)
put_prev_task(rq, p);
@@ -4097,15 +4017,14 @@ change:
if (running)
p->sched_class->set_curr_task(rq);
if (queued) {
- int enqueue_flags = ENQUEUE_RESTORE;
/*
* We enqueue to tail when the priority of a task is
* increased (user space view).
*/
- if (oldprio <= p->prio)
- enqueue_flags |= ENQUEUE_HEAD;
+ if (oldprio < p->prio)
+ queue_flags |= ENQUEUE_HEAD;
- enqueue_task(rq, p, enqueue_flags);
+ enqueue_task(rq, p, queue_flags);
}
check_class_changed(rq, p, prev_class, oldprio);
@@ -5096,6 +5015,8 @@ void init_idle(struct task_struct *idle, int cpu)
idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
+ kasan_unpoison_task_stack(idle);
+
#ifdef CONFIG_SMP
/*
* Its possible that init_idle() gets called multiple times on a task,
@@ -5405,183 +5326,6 @@ static void migrate_tasks(struct rq *dead_rq)
}
#endif /* CONFIG_HOTPLUG_CPU */
-#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
-
-static struct ctl_table sd_ctl_dir[] = {
- {
- .procname = "sched_domain",
- .mode = 0555,
- },
- {}
-};
-
-static struct ctl_table sd_ctl_root[] = {
- {
- .procname = "kernel",
- .mode = 0555,
- .child = sd_ctl_dir,
- },
- {}
-};
-
-static struct ctl_table *sd_alloc_ctl_entry(int n)
-{
- struct ctl_table *entry =
- kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
-
- return entry;
-}
-
-static void sd_free_ctl_entry(struct ctl_table **tablep)
-{
- struct ctl_table *entry;
-
- /*
- * In the intermediate directories, both the child directory and
- * procname are dynamically allocated and could fail but the mode
- * will always be set. In the lowest directory the names are
- * static strings and all have proc handlers.
- */
- for (entry = *tablep; entry->mode; entry++) {
- if (entry->child)
- sd_free_ctl_entry(&entry->child);
- if (entry->proc_handler == NULL)
- kfree(entry->procname);
- }
-
- kfree(*tablep);
- *tablep = NULL;
-}
-
-static int min_load_idx = 0;
-static int max_load_idx = CPU_LOAD_IDX_MAX-1;
-
-static void
-set_table_entry(struct ctl_table *entry,
- const char *procname, void *data, int maxlen,
- umode_t mode, proc_handler *proc_handler,
- bool load_idx)
-{
- entry->procname = procname;
- entry->data = data;
- entry->maxlen = maxlen;
- entry->mode = mode;
- entry->proc_handler = proc_handler;
-
- if (load_idx) {
- entry->extra1 = &min_load_idx;
- entry->extra2 = &max_load_idx;
- }
-}
-
-static struct ctl_table *
-sd_alloc_ctl_domain_table(struct sched_domain *sd)
-{
- struct ctl_table *table = sd_alloc_ctl_entry(14);
-
- if (table == NULL)
- return NULL;
-
- set_table_entry(&table[0], "min_interval", &sd->min_interval,
- sizeof(long), 0644, proc_doulongvec_minmax, false);
- set_table_entry(&table[1], "max_interval", &sd->max_interval,
- sizeof(long), 0644, proc_doulongvec_minmax, false);
- set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
- sizeof(int), 0644, proc_dointvec_minmax, true);
- set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
- sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
- sizeof(int), 0644, proc_dointvec_minmax, false);
- set_table_entry(&table[9], "cache_nice_tries",
- &sd->cache_nice_tries,
- 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], "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[13] is terminator */
-
- return table;
-}
-
-static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
-{
- struct ctl_table *entry, *table;
- struct sched_domain *sd;
- int domain_num = 0, i;
- char buf[32];
-
- for_each_domain(cpu, sd)
- domain_num++;
- entry = table = sd_alloc_ctl_entry(domain_num + 1);
- if (table == NULL)
- return NULL;
-
- i = 0;
- for_each_domain(cpu, sd) {
- snprintf(buf, 32, "domain%d", i);
- entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0555;
- entry->child = sd_alloc_ctl_domain_table(sd);
- entry++;
- i++;
- }
- return table;
-}
-
-static struct ctl_table_header *sd_sysctl_header;
-static void register_sched_domain_sysctl(void)
-{
- int i, cpu_num = num_possible_cpus();
- struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
- char buf[32];
-
- WARN_ON(sd_ctl_dir[0].child);
- sd_ctl_dir[0].child = entry;
-
- if (entry == NULL)
- return;
-
- for_each_possible_cpu(i) {
- snprintf(buf, 32, "cpu%d", i);
- entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0555;
- entry->child = sd_alloc_ctl_cpu_table(i);
- entry++;
- }
-
- WARN_ON(sd_sysctl_header);
- sd_sysctl_header = register_sysctl_table(sd_ctl_root);
-}
-
-/* may be called multiple times per register */
-static void unregister_sched_domain_sysctl(void)
-{
- unregister_sysctl_table(sd_sysctl_header);
- sd_sysctl_header = NULL;
- if (sd_ctl_dir[0].child)
- sd_free_ctl_entry(&sd_ctl_dir[0].child);
-}
-#else
-static void register_sched_domain_sysctl(void)
-{
-}
-static void unregister_sched_domain_sysctl(void)
-{
-}
-#endif /* CONFIG_SCHED_DEBUG && CONFIG_SYSCTL */
-
static void set_rq_online(struct rq *rq)
{
if (!rq->online) {
@@ -5627,6 +5371,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
case CPU_UP_PREPARE:
rq->calc_load_update = calc_load_update;
+ account_reset_rq(rq);
break;
case CPU_ONLINE:
@@ -5692,16 +5437,6 @@ static int sched_cpu_active(struct notifier_block *nfb,
set_cpu_rq_start_time();
return NOTIFY_OK;
- case CPU_ONLINE:
- /*
- * At this point a starting CPU has marked itself as online via
- * set_cpu_online(). But it might not yet have marked itself
- * as active, which is essential from here on.
- */
- set_cpu_active(cpu, true);
- stop_machine_unpark(cpu);
- return NOTIFY_OK;
-
case CPU_DOWN_FAILED:
set_cpu_active(cpu, true);
return NOTIFY_OK;
@@ -6173,11 +5908,16 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
/* Setup the mask of cpus configured for isolated domains */
static int __init isolated_cpu_setup(char *str)
{
+ int ret;
+
alloc_bootmem_cpumask_var(&cpu_isolated_map);
- cpulist_parse(str, cpu_isolated_map);
+ ret = cpulist_parse(str, cpu_isolated_map);
+ if (ret) {
+ pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids);
+ return 0;
+ }
return 1;
}
-
__setup("isolcpus=", isolated_cpu_setup);
struct s_data {
@@ -6840,7 +6580,7 @@ static void sched_init_numa(void)
sched_domains_numa_masks[i][j] = mask;
- for (k = 0; k < nr_node_ids; k++) {
+ for_each_node(k) {
if (node_distance(j, k) > sched_domains_numa_distance[i])
continue;
@@ -7798,7 +7538,7 @@ void set_curr_task(int cpu, struct task_struct *p)
/* task_group_lock serializes the addition/removal of task groups */
static DEFINE_SPINLOCK(task_group_lock);
-static void free_sched_group(struct task_group *tg)
+static void sched_free_group(struct task_group *tg)
{
free_fair_sched_group(tg);
free_rt_sched_group(tg);
@@ -7824,7 +7564,7 @@ struct task_group *sched_create_group(struct task_group *parent)
return tg;
err:
- free_sched_group(tg);
+ sched_free_group(tg);
return ERR_PTR(-ENOMEM);
}
@@ -7844,27 +7584,24 @@ void sched_online_group(struct task_group *tg, struct task_group *parent)
}
/* rcu callback to free various structures associated with a task group */
-static void free_sched_group_rcu(struct rcu_head *rhp)
+static void sched_free_group_rcu(struct rcu_head *rhp)
{
/* now it should be safe to free those cfs_rqs */
- free_sched_group(container_of(rhp, struct task_group, rcu));
+ sched_free_group(container_of(rhp, struct task_group, rcu));
}
-/* Destroy runqueue etc associated with a task group */
void sched_destroy_group(struct task_group *tg)
{
/* wait for possible concurrent references to cfs_rqs complete */
- call_rcu(&tg->rcu, free_sched_group_rcu);
+ call_rcu(&tg->rcu, sched_free_group_rcu);
}
void sched_offline_group(struct task_group *tg)
{
unsigned long flags;
- int i;
/* end participation in shares distribution */
- for_each_possible_cpu(i)
- unregister_fair_sched_group(tg, i);
+ unregister_fair_sched_group(tg);
spin_lock_irqsave(&task_group_lock, flags);
list_del_rcu(&tg->list);
@@ -7890,7 +7627,7 @@ void sched_move_task(struct task_struct *tsk)
queued = task_on_rq_queued(tsk);
if (queued)
- dequeue_task(rq, tsk, DEQUEUE_SAVE);
+ dequeue_task(rq, tsk, DEQUEUE_SAVE | DEQUEUE_MOVE);
if (unlikely(running))
put_prev_task(rq, tsk);
@@ -7914,7 +7651,7 @@ void sched_move_task(struct task_struct *tsk)
if (unlikely(running))
tsk->sched_class->set_curr_task(rq);
if (queued)
- enqueue_task(rq, tsk, ENQUEUE_RESTORE);
+ enqueue_task(rq, tsk, ENQUEUE_RESTORE | ENQUEUE_MOVE);
task_rq_unlock(rq, tsk, &flags);
}
@@ -8315,31 +8052,26 @@ cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
if (IS_ERR(tg))
return ERR_PTR(-ENOMEM);
+ sched_online_group(tg, parent);
+
return &tg->css;
}
-static int cpu_cgroup_css_online(struct cgroup_subsys_state *css)
+static void cpu_cgroup_css_released(struct cgroup_subsys_state *css)
{
struct task_group *tg = css_tg(css);
- struct task_group *parent = css_tg(css->parent);
- if (parent)
- sched_online_group(tg, parent);
- return 0;
+ sched_offline_group(tg);
}
static void cpu_cgroup_css_free(struct cgroup_subsys_state *css)
{
struct task_group *tg = css_tg(css);
- sched_destroy_group(tg);
-}
-
-static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css)
-{
- struct task_group *tg = css_tg(css);
-
- sched_offline_group(tg);
+ /*
+ * Relies on the RCU grace period between css_released() and this.
+ */
+ sched_free_group(tg);
}
static void cpu_cgroup_fork(struct task_struct *task)
@@ -8699,14 +8431,13 @@ static struct cftype cpu_files[] = {
struct cgroup_subsys cpu_cgrp_subsys = {
.css_alloc = cpu_cgroup_css_alloc,
+ .css_released = cpu_cgroup_css_released,
.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,
.legacy_cftypes = cpu_files,
- .early_init = 1,
+ .early_init = true,
};
#endif /* CONFIG_CGROUP_SCHED */
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index dd7cbb55bbf2..4a811203c04a 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -145,13 +145,16 @@ static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
}
static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
- u64 reset)
+ u64 val)
{
struct cpuacct *ca = css_ca(css);
int err = 0;
int i;
- if (reset) {
+ /*
+ * Only allow '0' here to do a reset.
+ */
+ if (val) {
err = -EINVAL;
goto out;
}
@@ -235,23 +238,10 @@ static struct cftype files[] = {
void cpuacct_charge(struct task_struct *tsk, u64 cputime)
{
struct cpuacct *ca;
- int cpu;
-
- cpu = task_cpu(tsk);
rcu_read_lock();
-
- ca = task_ca(tsk);
-
- while (true) {
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
- *cpuusage += cputime;
-
- ca = parent_ca(ca);
- if (!ca)
- break;
- }
-
+ for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
+ *this_cpu_ptr(ca->cpuusage) += cputime;
rcu_read_unlock();
}
@@ -260,18 +250,13 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime)
*
* Note: it's the caller that updates the account of the root cgroup.
*/
-void cpuacct_account_field(struct task_struct *p, int index, u64 val)
+void cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
{
- struct kernel_cpustat *kcpustat;
struct cpuacct *ca;
rcu_read_lock();
- ca = task_ca(p);
- while (ca != &root_cpuacct) {
- kcpustat = this_cpu_ptr(ca->cpustat);
- kcpustat->cpustat[index] += val;
- ca = parent_ca(ca);
- }
+ for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca))
+ this_cpu_ptr(ca->cpustat)->cpustat[index] += val;
rcu_read_unlock();
}
@@ -279,5 +264,5 @@ struct cgroup_subsys cpuacct_cgrp_subsys = {
.css_alloc = cpuacct_css_alloc,
.css_free = cpuacct_css_free,
.legacy_cftypes = files,
- .early_init = 1,
+ .early_init = true,
};
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
index ed605624a5e7..ba72807c73d4 100644
--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
@@ -1,7 +1,7 @@
#ifdef CONFIG_CGROUP_CPUACCT
extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
-extern void cpuacct_account_field(struct task_struct *p, int index, u64 val);
+extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
#else
@@ -10,7 +10,7 @@ static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime)
}
static inline void
-cpuacct_account_field(struct task_struct *p, int index, u64 val)
+cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
{
}
diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c
new file mode 100644
index 000000000000..928c4ba32f68
--- /dev/null
+++ b/kernel/sched/cpufreq.c
@@ -0,0 +1,37 @@
+/*
+ * Scheduler code and data structures related to cpufreq.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Rafael J. Wysocki <[email protected]>
+ *
+ * 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 "sched.h"
+
+DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+/**
+ * cpufreq_set_update_util_data - Populate the CPU's update_util_data pointer.
+ * @cpu: The CPU to set the pointer for.
+ * @data: New pointer value.
+ *
+ * Set and publish the update_util_data pointer for the given CPU. That pointer
+ * points to a struct update_util_data object containing a callback function
+ * to call from cpufreq_update_util(). That function will be called from an RCU
+ * read-side critical section, so it must not sleep.
+ *
+ * Callers must use RCU-sched callbacks to free any memory that might be
+ * accessed via the old update_util_data pointer or invoke synchronize_sched()
+ * right after this function to avoid use-after-free.
+ */
+void cpufreq_set_update_util_data(int cpu, struct update_util_data *data)
+{
+ if (WARN_ON(data && !data->func))
+ return;
+
+ rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), data);
+}
+EXPORT_SYMBOL_GPL(cpufreq_set_update_util_data);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index b2ab2ffb1adc..75f98c5498d5 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -262,21 +262,21 @@ static __always_inline bool steal_account_process_tick(void)
#ifdef CONFIG_PARAVIRT
if (static_key_false(&paravirt_steal_enabled)) {
u64 steal;
- cputime_t steal_ct;
+ unsigned long steal_jiffies;
steal = paravirt_steal_clock(smp_processor_id());
steal -= this_rq()->prev_steal_time;
/*
- * cputime_t may be less precise than nsecs (eg: if it's
- * based on jiffies). Lets cast the result to cputime
+ * steal is in nsecs but our caller is expecting steal
+ * time in jiffies. Lets cast the result to jiffies
* granularity and account the rest on the next rounds.
*/
- steal_ct = nsecs_to_cputime(steal);
- this_rq()->prev_steal_time += cputime_to_nsecs(steal_ct);
+ steal_jiffies = nsecs_to_jiffies(steal);
+ this_rq()->prev_steal_time += jiffies_to_nsecs(steal_jiffies);
- account_steal_time(steal_ct);
- return steal_ct;
+ account_steal_time(jiffies_to_cputime(steal_jiffies));
+ return steal_jiffies;
}
#endif
return false;
@@ -668,26 +668,25 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-static unsigned long long vtime_delta(struct task_struct *tsk)
+static cputime_t vtime_delta(struct task_struct *tsk)
{
- unsigned long long clock;
+ unsigned long now = READ_ONCE(jiffies);
- clock = local_clock();
- if (clock < tsk->vtime_snap)
+ if (time_before(now, (unsigned long)tsk->vtime_snap))
return 0;
- return clock - tsk->vtime_snap;
+ return jiffies_to_cputime(now - tsk->vtime_snap);
}
static cputime_t get_vtime_delta(struct task_struct *tsk)
{
- unsigned long long delta = vtime_delta(tsk);
+ unsigned long now = READ_ONCE(jiffies);
+ unsigned long delta = now - tsk->vtime_snap;
WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_INACTIVE);
- tsk->vtime_snap += delta;
+ tsk->vtime_snap = now;
- /* CHECKME: always safe to convert nsecs to cputime? */
- return nsecs_to_cputime(delta);
+ return jiffies_to_cputime(delta);
}
static void __vtime_account_system(struct task_struct *tsk)
@@ -699,6 +698,9 @@ static void __vtime_account_system(struct task_struct *tsk)
void vtime_account_system(struct task_struct *tsk)
{
+ if (!vtime_delta(tsk))
+ return;
+
write_seqcount_begin(&tsk->vtime_seqcount);
__vtime_account_system(tsk);
write_seqcount_end(&tsk->vtime_seqcount);
@@ -707,7 +709,8 @@ void vtime_account_system(struct task_struct *tsk)
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
- __vtime_account_system(tsk);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
write_seqcount_end(&tsk->vtime_seqcount);
@@ -718,16 +721,19 @@ void vtime_account_user(struct task_struct *tsk)
cputime_t delta_cpu;
write_seqcount_begin(&tsk->vtime_seqcount);
- delta_cpu = get_vtime_delta(tsk);
tsk->vtime_snap_whence = VTIME_SYS;
- account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
+ if (vtime_delta(tsk)) {
+ delta_cpu = get_vtime_delta(tsk);
+ account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
+ }
write_seqcount_end(&tsk->vtime_seqcount);
}
void vtime_user_enter(struct task_struct *tsk)
{
write_seqcount_begin(&tsk->vtime_seqcount);
- __vtime_account_system(tsk);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
write_seqcount_end(&tsk->vtime_seqcount);
}
@@ -742,7 +748,8 @@ void vtime_guest_enter(struct task_struct *tsk)
* that can thus safely catch up with a tickless delta.
*/
write_seqcount_begin(&tsk->vtime_seqcount);
- __vtime_account_system(tsk);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
current->flags |= PF_VCPU;
write_seqcount_end(&tsk->vtime_seqcount);
}
@@ -772,7 +779,7 @@ void arch_vtime_task_switch(struct task_struct *prev)
write_seqcount_begin(&current->vtime_seqcount);
current->vtime_snap_whence = VTIME_SYS;
- current->vtime_snap = sched_clock_cpu(smp_processor_id());
+ current->vtime_snap = jiffies;
write_seqcount_end(&current->vtime_seqcount);
}
@@ -783,7 +790,7 @@ void vtime_init_idle(struct task_struct *t, int cpu)
local_irq_save(flags);
write_seqcount_begin(&t->vtime_seqcount);
t->vtime_snap_whence = VTIME_SYS;
- t->vtime_snap = sched_clock_cpu(cpu);
+ t->vtime_snap = jiffies;
write_seqcount_end(&t->vtime_seqcount);
local_irq_restore(flags);
}
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index cd64c979d0e1..affd97ec9f65 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -352,7 +352,15 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se,
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
- WARN_ON(!dl_se->dl_new || dl_se->dl_throttled);
+ WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
+
+ /*
+ * We are racing with the deadline timer. So, do nothing because
+ * the deadline timer handler will take care of properly recharging
+ * the runtime and postponing the deadline
+ */
+ if (dl_se->dl_throttled)
+ return;
/*
* We use the regular wall clock time to set deadlines in the
@@ -361,7 +369,6 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se,
*/
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
dl_se->runtime = pi_se->dl_runtime;
- dl_se->dl_new = 0;
}
/*
@@ -399,6 +406,9 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
dl_se->runtime = pi_se->dl_runtime;
}
+ if (dl_se->dl_yielded && dl_se->runtime > 0)
+ dl_se->runtime = 0;
+
/*
* We keep moving the deadline away until we get some
* available runtime for the entity. This ensures correct
@@ -420,7 +430,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se,
* entity.
*/
if (dl_time_before(dl_se->deadline, rq_clock(rq))) {
- printk_deferred_once("sched: DL replenish lagged to much\n");
+ printk_deferred_once("sched: DL replenish lagged too much\n");
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
dl_se->runtime = pi_se->dl_runtime;
}
@@ -500,15 +510,6 @@ static void update_dl_entity(struct sched_dl_entity *dl_se,
struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
struct rq *rq = rq_of_dl_rq(dl_rq);
- /*
- * The arrival of a new instance needs special treatment, i.e.,
- * the actual scheduling parameters have to be "renewed".
- */
- if (dl_se->dl_new) {
- setup_new_dl_entity(dl_se, pi_se);
- return;
- }
-
if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
dl_entity_overflow(dl_se, pi_se, rq_clock(rq))) {
dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
@@ -605,16 +606,6 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
}
/*
- * This is possible if switched_from_dl() raced against a running
- * callback that took the above !dl_task() path and we've since then
- * switched back into SCHED_DEADLINE.
- *
- * There's nothing to do except drop our task reference.
- */
- if (dl_se->dl_new)
- goto unlock;
-
- /*
* The task might have been boosted by someone else and might be in the
* boosting/deboosting path, its not throttled.
*/
@@ -726,6 +717,10 @@ static void update_curr_dl(struct rq *rq)
if (!dl_task(curr) || !on_dl_rq(dl_se))
return;
+ /* Kick cpufreq (see the comment in linux/cpufreq.h). */
+ if (cpu_of(rq) == smp_processor_id())
+ cpufreq_trigger_update(rq_clock(rq));
+
/*
* Consumed budget is computed considering the time as
* observed by schedulable tasks (excluding time spent
@@ -735,8 +730,11 @@ static void update_curr_dl(struct rq *rq)
* approach need further study.
*/
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
- if (unlikely((s64)delta_exec <= 0))
+ if (unlikely((s64)delta_exec <= 0)) {
+ if (unlikely(dl_se->dl_yielded))
+ goto throttle;
return;
+ }
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));
@@ -749,8 +747,10 @@ static void update_curr_dl(struct rq *rq)
sched_rt_avg_update(rq, delta_exec);
- dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec;
- if (dl_runtime_exceeded(dl_se)) {
+ dl_se->runtime -= delta_exec;
+
+throttle:
+ if (dl_runtime_exceeded(dl_se) || dl_se->dl_yielded) {
dl_se->dl_throttled = 1;
__dequeue_task_dl(rq, curr, 0);
if (unlikely(dl_se->dl_boosted || !start_dl_timer(curr)))
@@ -917,7 +917,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se,
* parameters of the task might need updating. Otherwise,
* we want a replenishment of its runtime.
*/
- if (dl_se->dl_new || flags & ENQUEUE_WAKEUP)
+ if (flags & ENQUEUE_WAKEUP)
update_dl_entity(dl_se, pi_se);
else if (flags & ENQUEUE_REPLENISH)
replenish_dl_entity(dl_se, pi_se);
@@ -994,18 +994,14 @@ static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags)
*/
static void yield_task_dl(struct rq *rq)
{
- struct task_struct *p = rq->curr;
-
/*
* We make the task go to sleep until its current deadline by
* forcing its runtime to zero. This way, update_curr_dl() stops
* it and the bandwidth timer will wake it up and will give it
* new scheduling parameters (thanks to dl_yielded=1).
*/
- if (p->dl.runtime > 0) {
- rq->curr->dl.dl_yielded = 1;
- p->dl.runtime = 0;
- }
+ rq->curr->dl.dl_yielded = 1;
+
update_rq_clock(rq);
update_curr_dl(rq);
/*
@@ -1722,6 +1718,9 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p)
*/
static void switched_to_dl(struct rq *rq, struct task_struct *p)
{
+ if (dl_time_before(p->dl.deadline, rq_clock(rq)))
+ setup_new_dl_entity(&p->dl, &p->dl);
+
if (task_on_rq_queued(p) && rq->curr != p) {
#ifdef CONFIG_SMP
if (p->nr_cpus_allowed > 1 && rq->dl.overloaded)
@@ -1768,8 +1767,7 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p,
*/
resched_curr(rq);
#endif /* CONFIG_SMP */
- } else
- switched_to_dl(rq, p);
+ }
}
const struct sched_class dl_sched_class = {
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 641511771ae6..4fbc3bd5ff60 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -16,6 +16,7 @@
#include <linux/kallsyms.h>
#include <linux/utsname.h>
#include <linux/mempolicy.h>
+#include <linux/debugfs.h>
#include "sched.h"
@@ -58,6 +59,309 @@ static unsigned long nsec_low(unsigned long long nsec)
#define SPLIT_NS(x) nsec_high(x), nsec_low(x)
+#define SCHED_FEAT(name, enabled) \
+ #name ,
+
+static const char * const sched_feat_names[] = {
+#include "features.h"
+};
+
+#undef SCHED_FEAT
+
+static int sched_feat_show(struct seq_file *m, void *v)
+{
+ int i;
+
+ for (i = 0; i < __SCHED_FEAT_NR; i++) {
+ if (!(sysctl_sched_features & (1UL << i)))
+ seq_puts(m, "NO_");
+ seq_printf(m, "%s ", sched_feat_names[i]);
+ }
+ seq_puts(m, "\n");
+
+ return 0;
+}
+
+#ifdef HAVE_JUMP_LABEL
+
+#define jump_label_key__true STATIC_KEY_INIT_TRUE
+#define jump_label_key__false STATIC_KEY_INIT_FALSE
+
+#define SCHED_FEAT(name, enabled) \
+ jump_label_key__##enabled ,
+
+struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
+#include "features.h"
+};
+
+#undef SCHED_FEAT
+
+static void sched_feat_disable(int i)
+{
+ static_key_disable(&sched_feat_keys[i]);
+}
+
+static void sched_feat_enable(int i)
+{
+ static_key_enable(&sched_feat_keys[i]);
+}
+#else
+static void sched_feat_disable(int i) { };
+static void sched_feat_enable(int i) { };
+#endif /* HAVE_JUMP_LABEL */
+
+static int sched_feat_set(char *cmp)
+{
+ int i;
+ int neg = 0;
+
+ if (strncmp(cmp, "NO_", 3) == 0) {
+ neg = 1;
+ cmp += 3;
+ }
+
+ for (i = 0; i < __SCHED_FEAT_NR; i++) {
+ if (strcmp(cmp, sched_feat_names[i]) == 0) {
+ if (neg) {
+ sysctl_sched_features &= ~(1UL << i);
+ sched_feat_disable(i);
+ } else {
+ sysctl_sched_features |= (1UL << i);
+ sched_feat_enable(i);
+ }
+ break;
+ }
+ }
+
+ return i;
+}
+
+static ssize_t
+sched_feat_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ char *cmp;
+ int i;
+ struct inode *inode;
+
+ if (cnt > 63)
+ cnt = 63;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+ cmp = strstrip(buf);
+
+ /* Ensure the static_key remains in a consistent state */
+ inode = file_inode(filp);
+ inode_lock(inode);
+ i = sched_feat_set(cmp);
+ inode_unlock(inode);
+ if (i == __SCHED_FEAT_NR)
+ return -EINVAL;
+
+ *ppos += cnt;
+
+ return cnt;
+}
+
+static int sched_feat_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, sched_feat_show, NULL);
+}
+
+static const struct file_operations sched_feat_fops = {
+ .open = sched_feat_open,
+ .write = sched_feat_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static __init int sched_init_debug(void)
+{
+ debugfs_create_file("sched_features", 0644, NULL, NULL,
+ &sched_feat_fops);
+
+ return 0;
+}
+late_initcall(sched_init_debug);
+
+#ifdef CONFIG_SMP
+
+#ifdef CONFIG_SYSCTL
+
+static struct ctl_table sd_ctl_dir[] = {
+ {
+ .procname = "sched_domain",
+ .mode = 0555,
+ },
+ {}
+};
+
+static struct ctl_table sd_ctl_root[] = {
+ {
+ .procname = "kernel",
+ .mode = 0555,
+ .child = sd_ctl_dir,
+ },
+ {}
+};
+
+static struct ctl_table *sd_alloc_ctl_entry(int n)
+{
+ struct ctl_table *entry =
+ kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
+
+ return entry;
+}
+
+static void sd_free_ctl_entry(struct ctl_table **tablep)
+{
+ struct ctl_table *entry;
+
+ /*
+ * In the intermediate directories, both the child directory and
+ * procname are dynamically allocated and could fail but the mode
+ * will always be set. In the lowest directory the names are
+ * static strings and all have proc handlers.
+ */
+ for (entry = *tablep; entry->mode; entry++) {
+ if (entry->child)
+ sd_free_ctl_entry(&entry->child);
+ if (entry->proc_handler == NULL)
+ kfree(entry->procname);
+ }
+
+ kfree(*tablep);
+ *tablep = NULL;
+}
+
+static int min_load_idx = 0;
+static int max_load_idx = CPU_LOAD_IDX_MAX-1;
+
+static void
+set_table_entry(struct ctl_table *entry,
+ const char *procname, void *data, int maxlen,
+ umode_t mode, proc_handler *proc_handler,
+ bool load_idx)
+{
+ entry->procname = procname;
+ entry->data = data;
+ entry->maxlen = maxlen;
+ entry->mode = mode;
+ entry->proc_handler = proc_handler;
+
+ if (load_idx) {
+ entry->extra1 = &min_load_idx;
+ entry->extra2 = &max_load_idx;
+ }
+}
+
+static struct ctl_table *
+sd_alloc_ctl_domain_table(struct sched_domain *sd)
+{
+ struct ctl_table *table = sd_alloc_ctl_entry(14);
+
+ if (table == NULL)
+ return NULL;
+
+ set_table_entry(&table[0], "min_interval", &sd->min_interval,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[1], "max_interval", &sd->max_interval,
+ sizeof(long), 0644, proc_doulongvec_minmax, false);
+ set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
+ sizeof(int), 0644, proc_dointvec_minmax, true);
+ set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
+ sizeof(int), 0644, proc_dointvec_minmax, false);
+ set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
+ sizeof(int), 0644, proc_dointvec_minmax, false);
+ set_table_entry(&table[9], "cache_nice_tries",
+ &sd->cache_nice_tries,
+ 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], "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[13] is terminator */
+
+ return table;
+}
+
+static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
+{
+ struct ctl_table *entry, *table;
+ struct sched_domain *sd;
+ int domain_num = 0, i;
+ char buf[32];
+
+ for_each_domain(cpu, sd)
+ domain_num++;
+ entry = table = sd_alloc_ctl_entry(domain_num + 1);
+ if (table == NULL)
+ return NULL;
+
+ i = 0;
+ for_each_domain(cpu, sd) {
+ snprintf(buf, 32, "domain%d", i);
+ entry->procname = kstrdup(buf, GFP_KERNEL);
+ entry->mode = 0555;
+ entry->child = sd_alloc_ctl_domain_table(sd);
+ entry++;
+ i++;
+ }
+ return table;
+}
+
+static struct ctl_table_header *sd_sysctl_header;
+void register_sched_domain_sysctl(void)
+{
+ int i, cpu_num = num_possible_cpus();
+ struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
+ char buf[32];
+
+ WARN_ON(sd_ctl_dir[0].child);
+ sd_ctl_dir[0].child = entry;
+
+ if (entry == NULL)
+ return;
+
+ for_each_possible_cpu(i) {
+ snprintf(buf, 32, "cpu%d", i);
+ entry->procname = kstrdup(buf, GFP_KERNEL);
+ entry->mode = 0555;
+ entry->child = sd_alloc_ctl_cpu_table(i);
+ entry++;
+ }
+
+ WARN_ON(sd_sysctl_header);
+ sd_sysctl_header = register_sysctl_table(sd_ctl_root);
+}
+
+/* may be called multiple times per register */
+void unregister_sched_domain_sysctl(void)
+{
+ unregister_sysctl_table(sd_sysctl_header);
+ sd_sysctl_header = NULL;
+ if (sd_ctl_dir[0].child)
+ sd_free_ctl_entry(&sd_ctl_dir[0].child);
+}
+#endif /* CONFIG_SYSCTL */
+#endif /* CONFIG_SMP */
+
#ifdef CONFIG_FAIR_GROUP_SCHED
static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
{
@@ -75,16 +379,18 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
PN(se->vruntime);
PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
- PN(se->statistics.wait_start);
- PN(se->statistics.sleep_start);
- PN(se->statistics.block_start);
- PN(se->statistics.sleep_max);
- PN(se->statistics.block_max);
- PN(se->statistics.exec_max);
- PN(se->statistics.slice_max);
- PN(se->statistics.wait_max);
- PN(se->statistics.wait_sum);
- P(se->statistics.wait_count);
+ if (schedstat_enabled()) {
+ PN(se->statistics.wait_start);
+ PN(se->statistics.sleep_start);
+ PN(se->statistics.block_start);
+ PN(se->statistics.sleep_max);
+ PN(se->statistics.block_max);
+ PN(se->statistics.exec_max);
+ PN(se->statistics.slice_max);
+ PN(se->statistics.wait_max);
+ PN(se->statistics.wait_sum);
+ P(se->statistics.wait_count);
+ }
#endif
P(se->load.weight);
#ifdef CONFIG_SMP
@@ -122,10 +428,12 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
(long long)(p->nvcsw + p->nivcsw),
p->prio);
#ifdef CONFIG_SCHEDSTATS
- SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
- SPLIT_NS(p->se.statistics.wait_sum),
- SPLIT_NS(p->se.sum_exec_runtime),
- SPLIT_NS(p->se.statistics.sum_sleep_runtime));
+ if (schedstat_enabled()) {
+ SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
+ SPLIT_NS(p->se.statistics.wait_sum),
+ SPLIT_NS(p->se.sum_exec_runtime),
+ SPLIT_NS(p->se.statistics.sum_sleep_runtime));
+ }
#else
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
0LL, 0L,
@@ -258,8 +566,17 @@ void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq)
{
+ struct dl_bw *dl_bw;
+
SEQ_printf(m, "\ndl_rq[%d]:\n", cpu);
SEQ_printf(m, " .%-30s: %ld\n", "dl_nr_running", dl_rq->dl_nr_running);
+#ifdef CONFIG_SMP
+ dl_bw = &cpu_rq(cpu)->rd->dl_bw;
+#else
+ dl_bw = &dl_rq->dl_bw;
+#endif
+ SEQ_printf(m, " .%-30s: %lld\n", "dl_bw->bw", dl_bw->bw);
+ SEQ_printf(m, " .%-30s: %lld\n", "dl_bw->total_bw", dl_bw->total_bw);
}
extern __read_mostly int sched_clock_running;
@@ -313,17 +630,18 @@ do { \
#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n);
- P(yld_count);
-
- P(sched_count);
- P(sched_goidle);
#ifdef CONFIG_SMP
P64(avg_idle);
P64(max_idle_balance_cost);
#endif
- P(ttwu_count);
- P(ttwu_local);
+ if (schedstat_enabled()) {
+ P(yld_count);
+ P(sched_count);
+ P(sched_goidle);
+ P(ttwu_count);
+ P(ttwu_local);
+ }
#undef P
#undef P64
@@ -569,38 +887,39 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
nr_switches = p->nvcsw + p->nivcsw;
#ifdef CONFIG_SCHEDSTATS
- PN(se.statistics.sum_sleep_runtime);
- PN(se.statistics.wait_start);
- PN(se.statistics.sleep_start);
- PN(se.statistics.block_start);
- PN(se.statistics.sleep_max);
- PN(se.statistics.block_max);
- PN(se.statistics.exec_max);
- PN(se.statistics.slice_max);
- PN(se.statistics.wait_max);
- PN(se.statistics.wait_sum);
- P(se.statistics.wait_count);
- PN(se.statistics.iowait_sum);
- P(se.statistics.iowait_count);
P(se.nr_migrations);
- P(se.statistics.nr_migrations_cold);
- P(se.statistics.nr_failed_migrations_affine);
- P(se.statistics.nr_failed_migrations_running);
- P(se.statistics.nr_failed_migrations_hot);
- P(se.statistics.nr_forced_migrations);
- P(se.statistics.nr_wakeups);
- P(se.statistics.nr_wakeups_sync);
- P(se.statistics.nr_wakeups_migrate);
- P(se.statistics.nr_wakeups_local);
- P(se.statistics.nr_wakeups_remote);
- P(se.statistics.nr_wakeups_affine);
- P(se.statistics.nr_wakeups_affine_attempts);
- P(se.statistics.nr_wakeups_passive);
- P(se.statistics.nr_wakeups_idle);
- {
+ if (schedstat_enabled()) {
u64 avg_atom, avg_per_cpu;
+ PN(se.statistics.sum_sleep_runtime);
+ PN(se.statistics.wait_start);
+ PN(se.statistics.sleep_start);
+ PN(se.statistics.block_start);
+ PN(se.statistics.sleep_max);
+ PN(se.statistics.block_max);
+ PN(se.statistics.exec_max);
+ PN(se.statistics.slice_max);
+ PN(se.statistics.wait_max);
+ PN(se.statistics.wait_sum);
+ P(se.statistics.wait_count);
+ PN(se.statistics.iowait_sum);
+ P(se.statistics.iowait_count);
+ P(se.statistics.nr_migrations_cold);
+ P(se.statistics.nr_failed_migrations_affine);
+ P(se.statistics.nr_failed_migrations_running);
+ P(se.statistics.nr_failed_migrations_hot);
+ P(se.statistics.nr_forced_migrations);
+ P(se.statistics.nr_wakeups);
+ P(se.statistics.nr_wakeups_sync);
+ P(se.statistics.nr_wakeups_migrate);
+ P(se.statistics.nr_wakeups_local);
+ P(se.statistics.nr_wakeups_remote);
+ P(se.statistics.nr_wakeups_affine);
+ P(se.statistics.nr_wakeups_affine_attempts);
+ P(se.statistics.nr_wakeups_passive);
+ P(se.statistics.nr_wakeups_idle);
+
avg_atom = p->se.sum_exec_runtime;
if (nr_switches)
avg_atom = div64_ul(avg_atom, nr_switches);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1926606ece80..0fe30e66aff1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -20,8 +20,8 @@
* Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
*/
-#include <linux/latencytop.h>
#include <linux/sched.h>
+#include <linux/latencytop.h>
#include <linux/cpumask.h>
#include <linux/cpuidle.h>
#include <linux/slab.h>
@@ -755,7 +755,9 @@ static void
update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
struct task_struct *p;
- u64 delta = rq_clock(rq_of(cfs_rq)) - se->statistics.wait_start;
+ u64 delta;
+
+ delta = rq_clock(rq_of(cfs_rq)) - se->statistics.wait_start;
if (entity_is_task(se)) {
p = task_of(se);
@@ -776,22 +778,12 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->statistics.wait_sum += delta;
se->statistics.wait_start = 0;
}
-#else
-static inline void
-update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-}
-
-static inline void
-update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
-{
-}
-#endif
/*
* Task is being enqueued - update stats:
*/
-static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+static inline void
+update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
/*
* Are we enqueueing a waiting task? (for current tasks
@@ -802,7 +794,7 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
}
static inline void
-update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
/*
* Mark the end of the wait period if dequeueing a
@@ -810,8 +802,41 @@ update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
*/
if (se != cfs_rq->curr)
update_stats_wait_end(cfs_rq, se);
+
+ if (flags & DEQUEUE_SLEEP) {
+ if (entity_is_task(se)) {
+ struct task_struct *tsk = task_of(se);
+
+ if (tsk->state & TASK_INTERRUPTIBLE)
+ se->statistics.sleep_start = rq_clock(rq_of(cfs_rq));
+ if (tsk->state & TASK_UNINTERRUPTIBLE)
+ se->statistics.block_start = rq_clock(rq_of(cfs_rq));
+ }
+ }
+
+}
+#else
+static inline void
+update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
}
+static inline void
+update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+}
+
+static inline void
+update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+}
+
+static inline void
+update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
+{
+}
+#endif
+
/*
* We are picking a new current task - update its stats:
*/
@@ -907,10 +932,11 @@ struct numa_group {
spinlock_t lock; /* nr_tasks, tasks */
int nr_tasks;
pid_t gid;
+ int active_nodes;
struct rcu_head rcu;
- nodemask_t active_nodes;
unsigned long total_faults;
+ unsigned long max_faults_cpu;
/*
* Faults_cpu is used to decide whether memory should move
* towards the CPU. As a consequence, these stats are weighted
@@ -969,6 +995,18 @@ static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)];
}
+/*
+ * A node triggering more than 1/3 as many NUMA faults as the maximum is
+ * considered part of a numa group's pseudo-interleaving set. Migrations
+ * between these nodes are slowed down, to allow things to settle down.
+ */
+#define ACTIVE_NODE_FRACTION 3
+
+static bool numa_is_active_node(int nid, struct numa_group *ng)
+{
+ return group_faults_cpu(ng, nid) * ACTIVE_NODE_FRACTION > ng->max_faults_cpu;
+}
+
/* 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)
@@ -1118,27 +1156,23 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
return true;
/*
- * Do not migrate if the destination is not a node that
- * is actively used by this numa group.
+ * Destination node is much more heavily used than the source
+ * node? Allow migration.
*/
- 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))
+ if (group_faults_cpu(ng, dst_nid) > group_faults_cpu(ng, src_nid) *
+ ACTIVE_NODE_FRACTION)
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.
+ * Distribute memory according to CPU & memory use on each node,
+ * with 3/4 hysteresis to avoid unnecessary memory migrations:
+ *
+ * faults_cpu(dst) 3 faults_cpu(src)
+ * --------------- * - > ---------------
+ * faults_mem(dst) 4 faults_mem(src)
*/
- return group_faults(p, dst_nid) < (group_faults(p, src_nid) * 3 / 4);
+ return group_faults_cpu(ng, dst_nid) * group_faults(p, src_nid) * 3 >
+ group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
}
static unsigned long weighted_cpuload(const int cpu);
@@ -1220,8 +1254,6 @@ static void task_numa_assign(struct task_numa_env *env,
{
if (env->best_task)
put_task_struct(env->best_task);
- if (p)
- get_task_struct(p);
env->best_task = p;
env->best_imp = imp;
@@ -1289,20 +1321,30 @@ static void task_numa_compare(struct task_numa_env *env,
long imp = env->p->numa_group ? groupimp : taskimp;
long moveimp = imp;
int dist = env->dist;
+ bool assigned = false;
rcu_read_lock();
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().
+ * No need to move the exiting task or idle task.
*/
if ((cur->flags & PF_EXITING) || is_idle_task(cur))
cur = NULL;
+ else {
+ /*
+ * The task_struct must be protected here to protect the
+ * p->numa_faults access in the task_weight since the
+ * numa_faults could already be freed in the following path:
+ * finish_task_switch()
+ * --> put_task_struct()
+ * --> __put_task_struct()
+ * --> task_numa_free()
+ */
+ get_task_struct(cur);
+ }
+
raw_spin_unlock_irq(&dst_rq->lock);
/*
@@ -1386,6 +1428,7 @@ balance:
*/
if (!load_too_imbalanced(src_load, dst_load, env)) {
imp = moveimp - 1;
+ put_task_struct(cur);
cur = NULL;
goto assign;
}
@@ -1411,9 +1454,16 @@ balance:
env->dst_cpu = select_idle_sibling(env->p, env->dst_cpu);
assign:
+ assigned = true;
task_numa_assign(env, cur, imp);
unlock:
rcu_read_unlock();
+ /*
+ * The dst_rq->curr isn't assigned. The protection for task_struct is
+ * finished.
+ */
+ if (cur && !assigned)
+ put_task_struct(cur);
}
static void task_numa_find_cpu(struct task_numa_env *env,
@@ -1468,7 +1518,7 @@ static int task_numa_migrate(struct task_struct *p)
.best_task = NULL,
.best_imp = 0,
- .best_cpu = -1
+ .best_cpu = -1,
};
struct sched_domain *sd;
unsigned long taskweight, groupweight;
@@ -1520,8 +1570,7 @@ static int task_numa_migrate(struct task_struct *p)
* 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)) {
+ if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) {
for_each_online_node(nid) {
if (nid == env.src_nid || nid == p->numa_preferred_nid)
continue;
@@ -1556,12 +1605,14 @@ static int task_numa_migrate(struct task_struct *p)
* trying for a better one later. Do not set the preferred node here.
*/
if (p->numa_group) {
+ struct numa_group *ng = p->numa_group;
+
if (env.best_cpu == -1)
nid = env.src_nid;
else
nid = env.dst_nid;
- if (node_isset(nid, p->numa_group->active_nodes))
+ if (ng->active_nodes > 1 && numa_is_active_node(env.dst_nid, ng))
sched_setnuma(p, env.dst_nid);
}
@@ -1611,20 +1662,15 @@ static void numa_migrate_preferred(struct task_struct *p)
}
/*
- * Find the nodes on which the workload is actively running. We do this by
+ * Find out how many nodes on the workload is actively running on. 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)
+static void numa_group_count_active_nodes(struct numa_group *numa_group)
{
unsigned long faults, max_faults = 0;
- int nid;
+ int nid, active_nodes = 0;
for_each_online_node(nid) {
faults = group_faults_cpu(numa_group, nid);
@@ -1634,12 +1680,12 @@ static void update_numa_active_node_mask(struct numa_group *numa_group)
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);
+ if (faults * ACTIVE_NODE_FRACTION > max_faults)
+ active_nodes++;
}
+
+ numa_group->max_faults_cpu = max_faults;
+ numa_group->active_nodes = active_nodes;
}
/*
@@ -1930,7 +1976,7 @@ static void task_numa_placement(struct task_struct *p)
update_task_scan_period(p, fault_types[0], fault_types[1]);
if (p->numa_group) {
- update_numa_active_node_mask(p->numa_group);
+ numa_group_count_active_nodes(p->numa_group);
spin_unlock_irq(group_lock);
max_nid = preferred_group_nid(p, max_group_nid);
}
@@ -1974,14 +2020,14 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
return;
atomic_set(&grp->refcount, 1);
+ grp->active_nodes = 1;
+ grp->max_faults_cpu = 0;
spin_lock_init(&grp->lock);
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 < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
grp->faults[i] = p->numa_faults[i];
@@ -2095,6 +2141,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
bool migrated = flags & TNF_MIGRATED;
int cpu_node = task_node(current);
int local = !!(flags & TNF_FAULT_LOCAL);
+ struct numa_group *ng;
int priv;
if (!static_branch_likely(&sched_numa_balancing))
@@ -2135,9 +2182,10 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
* actively using should be counted as local. This allows the
* scan rate to slow down when a workload has settled down.
*/
- if (!priv && !local && p->numa_group &&
- node_isset(cpu_node, p->numa_group->active_nodes) &&
- node_isset(mem_node, p->numa_group->active_nodes))
+ ng = p->numa_group;
+ if (!priv && !local && ng && ng->active_nodes > 1 &&
+ numa_is_active_node(cpu_node, ng) &&
+ numa_is_active_node(mem_node, ng))
local = 1;
task_numa_placement(p);
@@ -2808,7 +2856,8 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
{
struct cfs_rq *cfs_rq = cfs_rq_of(se);
u64 now = cfs_rq_clock_task(cfs_rq);
- int cpu = cpu_of(rq_of(cfs_rq));
+ struct rq *rq = rq_of(cfs_rq);
+ int cpu = cpu_of(rq);
/*
* Track task load average for carrying it to new CPU after migrated, and
@@ -2820,6 +2869,29 @@ static inline void update_load_avg(struct sched_entity *se, int update_tg)
if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
update_tg_load_avg(cfs_rq, 0);
+
+ if (cpu == smp_processor_id() && &rq->cfs == cfs_rq) {
+ unsigned long max = rq->cpu_capacity_orig;
+
+ /*
+ * There are a few boundary cases this might miss but it should
+ * get called often enough that that should (hopefully) not be
+ * a real problem -- added to that it only calls on the local
+ * CPU, so if we enqueue remotely we'll miss an update, but
+ * the next tick/schedule should update.
+ *
+ * It will not get called when we go idle, because the idle
+ * thread is a different class (!fair), nor will the utilization
+ * number include things like RT tasks.
+ *
+ * As is, the util number is not freq-invariant (we'd have to
+ * implement arch_scale_freq_capacity() for that).
+ *
+ * See cpu_util().
+ */
+ cpufreq_update_util(rq_clock(rq),
+ min(cfs_rq->avg.util_avg, max), max);
+ }
}
static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -3086,32 +3158,64 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
+static inline void check_schedstat_required(void)
+{
+#ifdef CONFIG_SCHEDSTATS
+ if (schedstat_enabled())
+ return;
+
+ /* Force schedstat enabled if a dependent tracepoint is active */
+ if (trace_sched_stat_wait_enabled() ||
+ trace_sched_stat_sleep_enabled() ||
+ trace_sched_stat_iowait_enabled() ||
+ trace_sched_stat_blocked_enabled() ||
+ trace_sched_stat_runtime_enabled()) {
+ pr_warn_once("Scheduler tracepoints stat_sleep, stat_iowait, "
+ "stat_blocked and stat_runtime require the "
+ "kernel parameter schedstats=enabled or "
+ "kernel.sched_schedstats=1\n");
+ }
+#endif
+}
+
static void
enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
+ bool renorm = !(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING);
+ bool curr = cfs_rq->curr == se;
+
/*
- * Update the normalized vruntime before updating min_vruntime
- * through calling update_curr().
+ * If we're the current task, we must renormalise before calling
+ * update_curr().
*/
- if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
+ if (renorm && curr)
se->vruntime += cfs_rq->min_vruntime;
+ update_curr(cfs_rq);
+
/*
- * Update run-time statistics of the 'current'.
+ * Otherwise, renormalise after, such that we're placed at the current
+ * moment in time, instead of some random moment in the past.
*/
- update_curr(cfs_rq);
+ if (renorm && !curr)
+ se->vruntime += cfs_rq->min_vruntime;
+
enqueue_entity_load_avg(cfs_rq, se);
account_entity_enqueue(cfs_rq, se);
update_cfs_shares(cfs_rq);
if (flags & ENQUEUE_WAKEUP) {
place_entity(cfs_rq, se, 0);
- enqueue_sleeper(cfs_rq, se);
+ if (schedstat_enabled())
+ enqueue_sleeper(cfs_rq, se);
}
- update_stats_enqueue(cfs_rq, se);
- check_spread(cfs_rq, se);
- if (se != cfs_rq->curr)
+ check_schedstat_required();
+ if (schedstat_enabled()) {
+ update_stats_enqueue(cfs_rq, se);
+ check_spread(cfs_rq, se);
+ }
+ if (!curr)
__enqueue_entity(cfs_rq, se);
se->on_rq = 1;
@@ -3177,19 +3281,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
update_curr(cfs_rq);
dequeue_entity_load_avg(cfs_rq, se);
- update_stats_dequeue(cfs_rq, se);
- if (flags & DEQUEUE_SLEEP) {
-#ifdef CONFIG_SCHEDSTATS
- if (entity_is_task(se)) {
- struct task_struct *tsk = task_of(se);
-
- if (tsk->state & TASK_INTERRUPTIBLE)
- se->statistics.sleep_start = rq_clock(rq_of(cfs_rq));
- if (tsk->state & TASK_UNINTERRUPTIBLE)
- se->statistics.block_start = rq_clock(rq_of(cfs_rq));
- }
-#endif
- }
+ if (schedstat_enabled())
+ update_stats_dequeue(cfs_rq, se, flags);
clear_buddies(cfs_rq, se);
@@ -3263,7 +3356,8 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* a CPU. So account for the time it spent waiting on the
* runqueue.
*/
- update_stats_wait_end(cfs_rq, se);
+ if (schedstat_enabled())
+ update_stats_wait_end(cfs_rq, se);
__dequeue_entity(cfs_rq, se);
update_load_avg(se, 1);
}
@@ -3276,7 +3370,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* least twice that of our own weight (i.e. dont track it
* when there are only lesser-weight tasks around):
*/
- if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
+ if (schedstat_enabled() && rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
se->statistics.slice_max = max(se->statistics.slice_max,
se->sum_exec_runtime - se->prev_sum_exec_runtime);
}
@@ -3359,9 +3453,13 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
/* throttle cfs_rqs exceeding runtime */
check_cfs_rq_runtime(cfs_rq);
- check_spread(cfs_rq, prev);
+ if (schedstat_enabled()) {
+ check_spread(cfs_rq, prev);
+ if (prev->on_rq)
+ update_stats_wait_start(cfs_rq, prev);
+ }
+
if (prev->on_rq) {
- update_stats_wait_start(cfs_rq, prev);
/* Put 'current' back into the tree. */
__enqueue_entity(cfs_rq, prev);
/* in !on_rq case, update occurred at dequeue */
@@ -4443,9 +4541,17 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
/* scale is effectively 1 << i now, and >> i divides by scale */
- old_load = this_rq->cpu_load[i] - tickless_load;
+ old_load = this_rq->cpu_load[i];
old_load = decay_load_missed(old_load, pending_updates - 1, i);
- old_load += tickless_load;
+ if (tickless_load) {
+ old_load -= decay_load_missed(tickless_load, pending_updates - 1, i);
+ /*
+ * old_load can never be a negative value because a
+ * decayed tickless_load cannot be greater than the
+ * original tickless_load.
+ */
+ old_load += tickless_load;
+ }
new_load = this_load;
/*
* Round up the averaging division if load is increasing. This
@@ -4468,6 +4574,25 @@ static unsigned long weighted_cpuload(const int cpu)
}
#ifdef CONFIG_NO_HZ_COMMON
+static void __update_cpu_load_nohz(struct rq *this_rq,
+ unsigned long curr_jiffies,
+ unsigned long load,
+ int active)
+{
+ unsigned long pending_updates;
+
+ pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+ if (pending_updates) {
+ this_rq->last_load_update_tick = curr_jiffies;
+ /*
+ * In the regular NOHZ case, we were idle, this means load 0.
+ * In the NOHZ_FULL case, we were non-idle, we should consider
+ * its weighted load.
+ */
+ __update_cpu_load(this_rq, load, pending_updates, active);
+ }
+}
+
/*
* There is no sane way to deal with nohz on smp when using jiffies because the
* cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
@@ -4485,22 +4610,15 @@ static unsigned long weighted_cpuload(const int cpu)
* Called from nohz_idle_balance() to update the load ratings before doing the
* idle balance.
*/
-static void update_idle_cpu_load(struct rq *this_rq)
+static void update_cpu_load_idle(struct rq *this_rq)
{
- unsigned long curr_jiffies = READ_ONCE(jiffies);
- unsigned long load = weighted_cpuload(cpu_of(this_rq));
- unsigned long pending_updates;
-
/*
* bail if there's load or we're actually up-to-date.
*/
- if (load || curr_jiffies == this_rq->last_load_update_tick)
+ if (weighted_cpuload(cpu_of(this_rq)))
return;
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- this_rq->last_load_update_tick = curr_jiffies;
-
- __update_cpu_load(this_rq, load, pending_updates, 0);
+ __update_cpu_load_nohz(this_rq, READ_ONCE(jiffies), 0, 0);
}
/*
@@ -4511,22 +4629,12 @@ void update_cpu_load_nohz(int active)
struct rq *this_rq = this_rq();
unsigned long curr_jiffies = READ_ONCE(jiffies);
unsigned long load = active ? weighted_cpuload(cpu_of(this_rq)) : 0;
- unsigned long pending_updates;
if (curr_jiffies == this_rq->last_load_update_tick)
return;
raw_spin_lock(&this_rq->lock);
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- if (pending_updates) {
- this_rq->last_load_update_tick = curr_jiffies;
- /*
- * In the regular NOHZ case, we were idle, this means load 0.
- * In the NOHZ_FULL case, we were non-idle, we should consider
- * its weighted load.
- */
- __update_cpu_load(this_rq, load, pending_updates, active);
- }
+ __update_cpu_load_nohz(this_rq, curr_jiffies, load, active);
raw_spin_unlock(&this_rq->lock);
}
#endif /* CONFIG_NO_HZ */
@@ -4538,7 +4646,7 @@ void update_cpu_load_active(struct rq *this_rq)
{
unsigned long load = weighted_cpuload(cpu_of(this_rq));
/*
- * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
+ * See the mess around update_cpu_load_idle() / update_cpu_load_nohz().
*/
this_rq->last_load_update_tick = jiffies;
__update_cpu_load(this_rq, load, 1, 1);
@@ -4971,7 +5079,19 @@ static int select_idle_sibling(struct task_struct *p, int target)
return i;
/*
- * Otherwise, iterate the domains and find an elegible idle cpu.
+ * Otherwise, iterate the domains and find an eligible idle cpu.
+ *
+ * A completely idle sched group at higher domains is more
+ * desirable than an idle group at a lower level, because lower
+ * domains have smaller groups and usually share hardware
+ * resources which causes tasks to contend on them, e.g. x86
+ * hyperthread siblings in the lowest domain (SMT) can contend
+ * on the shared cpu pipeline.
+ *
+ * However, while we prefer idle groups at higher domains
+ * finding an idle cpu at the lowest domain is still better than
+ * returning 'target', which we've already established, isn't
+ * idle.
*/
sd = rcu_dereference(per_cpu(sd_llc, target));
for_each_lower_domain(sd) {
@@ -4981,11 +5101,16 @@ static int select_idle_sibling(struct task_struct *p, int target)
tsk_cpus_allowed(p)))
goto next;
+ /* Ensure the entire group is idle */
for_each_cpu(i, sched_group_cpus(sg)) {
if (i == target || !idle_cpu(i))
goto next;
}
+ /*
+ * It doesn't matter which cpu we pick, the
+ * whole group is idle.
+ */
target = cpumask_first_and(sched_group_cpus(sg),
tsk_cpus_allowed(p));
goto done;
@@ -7832,7 +7957,7 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
if (time_after_eq(jiffies, rq->next_balance)) {
raw_spin_lock_irq(&rq->lock);
update_rq_clock(rq);
- update_idle_cpu_load(rq);
+ update_cpu_load_idle(rq);
raw_spin_unlock_irq(&rq->lock);
rebalance_domains(rq, CPU_IDLE);
}
@@ -8218,11 +8343,8 @@ void free_fair_sched_group(struct task_group *tg)
for_each_possible_cpu(i) {
if (tg->cfs_rq)
kfree(tg->cfs_rq[i]);
- if (tg->se) {
- if (tg->se[i])
- remove_entity_load_avg(tg->se[i]);
+ if (tg->se)
kfree(tg->se[i]);
- }
}
kfree(tg->cfs_rq);
@@ -8270,21 +8392,29 @@ err:
return 0;
}
-void unregister_fair_sched_group(struct task_group *tg, int cpu)
+void unregister_fair_sched_group(struct task_group *tg)
{
- struct rq *rq = cpu_rq(cpu);
unsigned long flags;
+ struct rq *rq;
+ int cpu;
- /*
- * Only empty task groups can be destroyed; so we can speculatively
- * check on_list without danger of it being re-added.
- */
- if (!tg->cfs_rq[cpu]->on_list)
- return;
+ for_each_possible_cpu(cpu) {
+ if (tg->se[cpu])
+ remove_entity_load_avg(tg->se[cpu]);
- raw_spin_lock_irqsave(&rq->lock, flags);
- list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ /*
+ * Only empty task groups can be destroyed; so we can speculatively
+ * check on_list without danger of it being re-added.
+ */
+ if (!tg->cfs_rq[cpu]->on_list)
+ continue;
+
+ rq = cpu_rq(cpu);
+
+ raw_spin_lock_irqsave(&rq->lock, flags);
+ list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
+ raw_spin_unlock_irqrestore(&rq->lock, flags);
+ }
}
void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
@@ -8366,7 +8496,7 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
return 1;
}
-void unregister_fair_sched_group(struct task_group *tg, int cpu) { }
+void unregister_fair_sched_group(struct task_group *tg) { }
#endif /* CONFIG_FAIR_GROUP_SCHED */
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index de0e786b2667..bd12c6c714ec 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -4,6 +4,7 @@
#include <linux/sched.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
+#include <linux/cpuhotplug.h>
#include <linux/tick.h>
#include <linux/mm.h>
#include <linux/stackprotector.h>
@@ -162,7 +163,7 @@ static void cpuidle_idle_call(void)
*/
if (idle_should_freeze()) {
entered_state = cpuidle_enter_freeze(drv, dev);
- if (entered_state >= 0) {
+ if (entered_state > 0) {
local_irq_enable();
goto exit_idle;
}
@@ -193,8 +194,6 @@ exit_idle:
rcu_idle_exit();
}
-DEFINE_PER_CPU(bool, cpu_dead_idle);
-
/*
* Generic idle loop implementation
*
@@ -221,10 +220,7 @@ static void cpu_idle_loop(void)
rmb();
if (cpu_is_offline(smp_processor_id())) {
- rcu_cpu_notify(NULL, CPU_DYING_IDLE,
- (void *)(long)smp_processor_id());
- smp_mb(); /* all activity before dead. */
- this_cpu_write(cpu_dead_idle, true);
+ cpuhp_report_idle_dead();
arch_cpu_idle_dead();
}
@@ -291,5 +287,6 @@ void cpu_startup_entry(enum cpuhp_state state)
boot_init_stack_canary();
#endif
arch_cpu_idle_prepare();
+ cpuhp_online_idle(state);
cpu_idle_loop();
}
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 8ec86abe0ea1..c41ea7ac1764 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -58,7 +58,15 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
raw_spin_lock(&rt_b->rt_runtime_lock);
if (!rt_b->rt_period_active) {
rt_b->rt_period_active = 1;
- hrtimer_forward_now(&rt_b->rt_period_timer, rt_b->rt_period);
+ /*
+ * SCHED_DEADLINE updates the bandwidth, as a run away
+ * RT task with a DL task could hog a CPU. But DL does
+ * not reset the period. If a deadline task was running
+ * without an RT task running, it can cause RT tasks to
+ * throttle when they start up. Kick the timer right away
+ * to update the period.
+ */
+ hrtimer_forward_now(&rt_b->rt_period_timer, ns_to_ktime(0));
hrtimer_start_expires(&rt_b->rt_period_timer, HRTIMER_MODE_ABS_PINNED);
}
raw_spin_unlock(&rt_b->rt_runtime_lock);
@@ -436,7 +444,7 @@ static void dequeue_top_rt_rq(struct rt_rq *rt_rq);
static inline int on_rt_rq(struct sched_rt_entity *rt_se)
{
- return !list_empty(&rt_se->run_list);
+ return rt_se->on_rq;
}
#ifdef CONFIG_RT_GROUP_SCHED
@@ -482,8 +490,8 @@ static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se)
return rt_se->my_q;
}
-static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head);
-static void dequeue_rt_entity(struct sched_rt_entity *rt_se);
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags);
static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
{
@@ -499,7 +507,7 @@ static void sched_rt_rq_enqueue(struct rt_rq *rt_rq)
if (!rt_se)
enqueue_top_rt_rq(rt_rq);
else if (!on_rt_rq(rt_se))
- enqueue_rt_entity(rt_se, false);
+ enqueue_rt_entity(rt_se, 0);
if (rt_rq->highest_prio.curr < curr->prio)
resched_curr(rq);
@@ -516,7 +524,7 @@ static void sched_rt_rq_dequeue(struct rt_rq *rt_rq)
if (!rt_se)
dequeue_top_rt_rq(rt_rq);
else if (on_rt_rq(rt_se))
- dequeue_rt_entity(rt_se);
+ dequeue_rt_entity(rt_se, 0);
}
static inline int rt_rq_throttled(struct rt_rq *rt_rq)
@@ -945,6 +953,10 @@ static void update_curr_rt(struct rq *rq)
if (curr->sched_class != &rt_sched_class)
return;
+ /* Kick cpufreq (see the comment in linux/cpufreq.h). */
+ if (cpu_of(rq) == smp_processor_id())
+ cpufreq_trigger_update(rq_clock(rq));
+
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
if (unlikely((s64)delta_exec <= 0))
return;
@@ -1142,12 +1154,27 @@ unsigned int rt_se_nr_running(struct sched_rt_entity *rt_se)
}
static inline
+unsigned int rt_se_rr_nr_running(struct sched_rt_entity *rt_se)
+{
+ struct rt_rq *group_rq = group_rt_rq(rt_se);
+ struct task_struct *tsk;
+
+ if (group_rq)
+ return group_rq->rr_nr_running;
+
+ tsk = rt_task_of(rt_se);
+
+ return (tsk->policy == SCHED_RR) ? 1 : 0;
+}
+
+static inline
void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
{
int prio = rt_se_prio(rt_se);
WARN_ON(!rt_prio(prio));
rt_rq->rt_nr_running += rt_se_nr_running(rt_se);
+ rt_rq->rr_nr_running += rt_se_rr_nr_running(rt_se);
inc_rt_prio(rt_rq, prio);
inc_rt_migration(rt_se, rt_rq);
@@ -1160,13 +1187,37 @@ void dec_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq)
WARN_ON(!rt_prio(rt_se_prio(rt_se)));
WARN_ON(!rt_rq->rt_nr_running);
rt_rq->rt_nr_running -= rt_se_nr_running(rt_se);
+ rt_rq->rr_nr_running -= rt_se_rr_nr_running(rt_se);
dec_rt_prio(rt_rq, rt_se_prio(rt_se));
dec_rt_migration(rt_se, rt_rq);
dec_rt_group(rt_se, rt_rq);
}
-static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
+/*
+ * Change rt_se->run_list location unless SAVE && !MOVE
+ *
+ * assumes ENQUEUE/DEQUEUE flags match
+ */
+static inline bool move_entity(unsigned int flags)
+{
+ if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) == DEQUEUE_SAVE)
+ return false;
+
+ return true;
+}
+
+static void __delist_rt_entity(struct sched_rt_entity *rt_se, struct rt_prio_array *array)
+{
+ list_del_init(&rt_se->run_list);
+
+ if (list_empty(array->queue + rt_se_prio(rt_se)))
+ __clear_bit(rt_se_prio(rt_se), array->bitmap);
+
+ rt_se->on_list = 0;
+}
+
+static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
@@ -1179,26 +1230,37 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
* get throttled and the current group doesn't have any other
* active members.
*/
- if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running))
+ if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) {
+ if (rt_se->on_list)
+ __delist_rt_entity(rt_se, array);
return;
+ }
- if (head)
- list_add(&rt_se->run_list, queue);
- else
- list_add_tail(&rt_se->run_list, queue);
- __set_bit(rt_se_prio(rt_se), array->bitmap);
+ if (move_entity(flags)) {
+ WARN_ON_ONCE(rt_se->on_list);
+ if (flags & ENQUEUE_HEAD)
+ list_add(&rt_se->run_list, queue);
+ else
+ list_add_tail(&rt_se->run_list, queue);
+
+ __set_bit(rt_se_prio(rt_se), array->bitmap);
+ rt_se->on_list = 1;
+ }
+ rt_se->on_rq = 1;
inc_rt_tasks(rt_se, rt_rq);
}
-static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
+static void __dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
struct rt_prio_array *array = &rt_rq->active;
- list_del_init(&rt_se->run_list);
- if (list_empty(array->queue + rt_se_prio(rt_se)))
- __clear_bit(rt_se_prio(rt_se), array->bitmap);
+ if (move_entity(flags)) {
+ WARN_ON_ONCE(!rt_se->on_list);
+ __delist_rt_entity(rt_se, array);
+ }
+ rt_se->on_rq = 0;
dec_rt_tasks(rt_se, rt_rq);
}
@@ -1207,7 +1269,7 @@ static void __dequeue_rt_entity(struct sched_rt_entity *rt_se)
* Because the prio of an upper entry depends on the lower
* entries, we must remove entries top - down.
*/
-static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
+static void dequeue_rt_stack(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct sched_rt_entity *back = NULL;
@@ -1220,31 +1282,31 @@ static void dequeue_rt_stack(struct sched_rt_entity *rt_se)
for (rt_se = back; rt_se; rt_se = rt_se->back) {
if (on_rt_rq(rt_se))
- __dequeue_rt_entity(rt_se);
+ __dequeue_rt_entity(rt_se, flags);
}
}
-static void enqueue_rt_entity(struct sched_rt_entity *rt_se, bool head)
+static void enqueue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rq *rq = rq_of_rt_se(rt_se);
- dequeue_rt_stack(rt_se);
+ dequeue_rt_stack(rt_se, flags);
for_each_sched_rt_entity(rt_se)
- __enqueue_rt_entity(rt_se, head);
+ __enqueue_rt_entity(rt_se, flags);
enqueue_top_rt_rq(&rq->rt);
}
-static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
+static void dequeue_rt_entity(struct sched_rt_entity *rt_se, unsigned int flags)
{
struct rq *rq = rq_of_rt_se(rt_se);
- dequeue_rt_stack(rt_se);
+ dequeue_rt_stack(rt_se, flags);
for_each_sched_rt_entity(rt_se) {
struct rt_rq *rt_rq = group_rt_rq(rt_se);
if (rt_rq && rt_rq->rt_nr_running)
- __enqueue_rt_entity(rt_se, false);
+ __enqueue_rt_entity(rt_se, flags);
}
enqueue_top_rt_rq(&rq->rt);
}
@@ -1260,7 +1322,7 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags)
if (flags & ENQUEUE_WAKEUP)
rt_se->timeout = 0;
- enqueue_rt_entity(rt_se, flags & ENQUEUE_HEAD);
+ enqueue_rt_entity(rt_se, flags);
if (!task_current(rq, p) && p->nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
@@ -1271,7 +1333,7 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
struct sched_rt_entity *rt_se = &p->rt;
update_curr_rt(rq);
- dequeue_rt_entity(rt_se);
+ dequeue_rt_entity(rt_se, flags);
dequeue_pushable_task(rq, p);
}
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 10f16374df7f..ec2e8d23527e 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3,6 +3,7 @@
#include <linux/sched/sysctl.h>
#include <linux/sched/rt.h>
#include <linux/sched/deadline.h>
+#include <linux/binfmts.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>
@@ -313,12 +314,11 @@ extern int tg_nop(struct task_group *tg, void *data);
extern void free_fair_sched_group(struct task_group *tg);
extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
-extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
+extern void unregister_fair_sched_group(struct task_group *tg);
extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
struct sched_entity *se, int cpu,
struct sched_entity *parent);
extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
-extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
@@ -450,6 +450,7 @@ static inline int rt_bandwidth_enabled(void)
struct rt_rq {
struct rt_prio_array active;
unsigned int rt_nr_running;
+ unsigned int rr_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
struct {
int curr; /* highest queued rt task prio */
@@ -909,6 +910,18 @@ static inline unsigned int group_first_cpu(struct sched_group *group)
extern int group_balance_cpu(struct sched_group *sg);
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
+void register_sched_domain_sysctl(void);
+void unregister_sched_domain_sysctl(void);
+#else
+static inline void register_sched_domain_sysctl(void)
+{
+}
+static inline void unregister_sched_domain_sysctl(void)
+{
+}
+#endif
+
#else
static inline void sched_ttwu_pending(void) { }
@@ -1022,6 +1035,7 @@ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
extern struct static_key_false sched_numa_balancing;
+extern struct static_key_false sched_schedstats;
static inline u64 global_rt_period(void)
{
@@ -1130,18 +1144,40 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
extern const int sched_prio_to_weight[40];
extern const u32 sched_prio_to_wmult[40];
+/*
+ * {de,en}queue flags:
+ *
+ * DEQUEUE_SLEEP - task is no longer runnable
+ * ENQUEUE_WAKEUP - task just became runnable
+ *
+ * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
+ * are in a known state which allows modification. Such pairs
+ * should preserve as much state as possible.
+ *
+ * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
+ * in the runqueue.
+ *
+ * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
+ * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
+ * ENQUEUE_WAKING - sched_class::task_waking was called
+ *
+ */
+
+#define DEQUEUE_SLEEP 0x01
+#define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */
+#define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */
+
#define ENQUEUE_WAKEUP 0x01
-#define ENQUEUE_HEAD 0x02
+#define ENQUEUE_RESTORE 0x02
+#define ENQUEUE_MOVE 0x04
+
+#define ENQUEUE_HEAD 0x08
+#define ENQUEUE_REPLENISH 0x10
#ifdef CONFIG_SMP
-#define ENQUEUE_WAKING 0x04 /* sched_class::task_waking was called */
+#define ENQUEUE_WAKING 0x20
#else
#define ENQUEUE_WAKING 0x00
#endif
-#define ENQUEUE_REPLENISH 0x08
-#define ENQUEUE_RESTORE 0x10
-
-#define DEQUEUE_SLEEP 0x01
-#define DEQUEUE_SAVE 0x02
#define RETRY_TASK ((void *)-1UL)
@@ -1278,6 +1314,35 @@ unsigned long to_ratio(u64 period, u64 runtime);
extern void init_entity_runnable_average(struct sched_entity *se);
+#ifdef CONFIG_NO_HZ_FULL
+extern bool sched_can_stop_tick(struct rq *rq);
+
+/*
+ * Tick may be needed by tasks in the runqueue depending on their policy and
+ * requirements. If tick is needed, lets send the target an IPI to kick it out of
+ * nohz mode if necessary.
+ */
+static inline void sched_update_tick_dependency(struct rq *rq)
+{
+ int cpu;
+
+ if (!tick_nohz_full_enabled())
+ return;
+
+ cpu = cpu_of(rq);
+
+ if (!tick_nohz_full_cpu(cpu))
+ return;
+
+ if (sched_can_stop_tick(rq))
+ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
+ else
+ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
+}
+#else
+static inline void sched_update_tick_dependency(struct rq *rq) { }
+#endif
+
static inline void add_nr_running(struct rq *rq, unsigned count)
{
unsigned prev_nr = rq->nr_running;
@@ -1289,26 +1354,16 @@ static inline void add_nr_running(struct rq *rq, unsigned count)
if (!rq->rd->overload)
rq->rd->overload = true;
#endif
-
-#ifdef CONFIG_NO_HZ_FULL
- if (tick_nohz_full_cpu(rq->cpu)) {
- /*
- * Tick is needed if more than one task runs on a CPU.
- * Send the target an IPI to kick it out of nohz mode.
- *
- * We assume that IPI implies full memory barrier and the
- * new value of rq->nr_running is visible on reception
- * from the target.
- */
- tick_nohz_full_kick_cpu(rq->cpu);
- }
-#endif
}
+
+ sched_update_tick_dependency(rq);
}
static inline void sub_nr_running(struct rq *rq, unsigned count)
{
rq->nr_running -= count;
+ /* Check if we still need preemption */
+ sched_update_tick_dependency(rq);
}
static inline void rq_last_tick_reset(struct rq *rq)
@@ -1738,3 +1793,64 @@ static inline u64 irq_time_read(int cpu)
}
#endif /* CONFIG_64BIT */
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
+
+#ifdef CONFIG_CPU_FREQ
+DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
+
+/**
+ * cpufreq_update_util - Take a note about CPU utilization changes.
+ * @time: Current time.
+ * @util: Current utilization.
+ * @max: Utilization ceiling.
+ *
+ * This function is called by the scheduler on every invocation of
+ * update_load_avg() on the CPU whose utilization is being updated.
+ *
+ * It can only be called from RCU-sched read-side critical sections.
+ */
+static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
+{
+ struct update_util_data *data;
+
+ data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
+ if (data)
+ data->func(data, time, util, max);
+}
+
+/**
+ * cpufreq_trigger_update - Trigger CPU performance state evaluation if needed.
+ * @time: Current time.
+ *
+ * The way cpufreq is currently arranged requires it to evaluate the CPU
+ * performance state (frequency/voltage) on a regular basis to prevent it from
+ * being stuck in a completely inadequate performance level for too long.
+ * That is not guaranteed to happen if the updates are only triggered from CFS,
+ * though, because they may not be coming in if RT or deadline tasks are active
+ * all the time (or there are RT and DL tasks only).
+ *
+ * As a workaround for that issue, this function is called by the RT and DL
+ * sched classes to trigger extra cpufreq updates to prevent it from stalling,
+ * but that really is a band-aid. Going forward it should be replaced with
+ * solutions targeted more specifically at RT and DL tasks.
+ */
+static inline void cpufreq_trigger_update(u64 time)
+{
+ cpufreq_update_util(time, ULONG_MAX, 0);
+}
+#else
+static inline void cpufreq_update_util(u64 time, unsigned long util, unsigned long max) {}
+static inline void cpufreq_trigger_update(u64 time) {}
+#endif /* CONFIG_CPU_FREQ */
+
+static inline void account_reset_rq(struct rq *rq)
+{
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+ rq->prev_irq_time = 0;
+#endif
+#ifdef CONFIG_PARAVIRT
+ rq->prev_steal_time = 0;
+#endif
+#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
+ rq->prev_steal_time_rq = 0;
+#endif
+}
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index b0fbc7632de5..70b3b6a20fb0 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -29,9 +29,10 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
if (rq)
rq->rq_sched_info.run_delay += delta;
}
-# define schedstat_inc(rq, field) do { (rq)->field++; } while (0)
-# define schedstat_add(rq, field, amt) do { (rq)->field += (amt); } while (0)
-# define schedstat_set(var, val) do { var = (val); } while (0)
+# define schedstat_enabled() static_branch_unlikely(&sched_schedstats)
+# define schedstat_inc(rq, field) do { if (schedstat_enabled()) { (rq)->field++; } } while (0)
+# define schedstat_add(rq, field, amt) do { if (schedstat_enabled()) { (rq)->field += (amt); } } while (0)
+# define schedstat_set(var, val) do { if (schedstat_enabled()) { var = (val); } } while (0)
#else /* !CONFIG_SCHEDSTATS */
static inline void
rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
@@ -42,6 +43,7 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long delta)
static inline void
rq_sched_info_depart(struct rq *rq, unsigned long long delta)
{}
+# define schedstat_enabled() 0
# define schedstat_inc(rq, field) do { } while (0)
# define schedstat_add(rq, field, amt) do { } while (0)
# define schedstat_set(var, val) do { } while (0)
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
new file mode 100644
index 000000000000..82f0dff90030
--- /dev/null
+++ b/kernel/sched/swait.c
@@ -0,0 +1,123 @@
+#include <linux/sched.h>
+#include <linux/swait.h>
+
+void __init_swait_queue_head(struct swait_queue_head *q, const char *name,
+ struct lock_class_key *key)
+{
+ raw_spin_lock_init(&q->lock);
+ lockdep_set_class_and_name(&q->lock, key, name);
+ INIT_LIST_HEAD(&q->task_list);
+}
+EXPORT_SYMBOL(__init_swait_queue_head);
+
+/*
+ * The thing about the wake_up_state() return value; I think we can ignore it.
+ *
+ * If for some reason it would return 0, that means the previously waiting
+ * task is already running, so it will observe condition true (or has already).
+ */
+void swake_up_locked(struct swait_queue_head *q)
+{
+ struct swait_queue *curr;
+
+ if (list_empty(&q->task_list))
+ return;
+
+ curr = list_first_entry(&q->task_list, typeof(*curr), task_list);
+ wake_up_process(curr->task);
+ list_del_init(&curr->task_list);
+}
+EXPORT_SYMBOL(swake_up_locked);
+
+void swake_up(struct swait_queue_head *q)
+{
+ unsigned long flags;
+
+ if (!swait_active(q))
+ return;
+
+ raw_spin_lock_irqsave(&q->lock, flags);
+ swake_up_locked(q);
+ raw_spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(swake_up);
+
+/*
+ * Does not allow usage from IRQ disabled, since we must be able to
+ * release IRQs to guarantee bounded hold time.
+ */
+void swake_up_all(struct swait_queue_head *q)
+{
+ struct swait_queue *curr;
+ LIST_HEAD(tmp);
+
+ if (!swait_active(q))
+ return;
+
+ raw_spin_lock_irq(&q->lock);
+ list_splice_init(&q->task_list, &tmp);
+ while (!list_empty(&tmp)) {
+ curr = list_first_entry(&tmp, typeof(*curr), task_list);
+
+ wake_up_state(curr->task, TASK_NORMAL);
+ list_del_init(&curr->task_list);
+
+ if (list_empty(&tmp))
+ break;
+
+ raw_spin_unlock_irq(&q->lock);
+ raw_spin_lock_irq(&q->lock);
+ }
+ raw_spin_unlock_irq(&q->lock);
+}
+EXPORT_SYMBOL(swake_up_all);
+
+void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
+{
+ wait->task = current;
+ if (list_empty(&wait->task_list))
+ list_add(&wait->task_list, &q->task_list);
+}
+
+void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&q->lock, flags);
+ __prepare_to_swait(q, wait);
+ set_current_state(state);
+ raw_spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(prepare_to_swait);
+
+long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state)
+{
+ if (signal_pending_state(state, current))
+ return -ERESTARTSYS;
+
+ prepare_to_swait(q, wait, state);
+
+ return 0;
+}
+EXPORT_SYMBOL(prepare_to_swait_event);
+
+void __finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
+{
+ __set_current_state(TASK_RUNNING);
+ if (!list_empty(&wait->task_list))
+ list_del_init(&wait->task_list);
+}
+
+void finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
+{
+ unsigned long flags;
+
+ __set_current_state(TASK_RUNNING);
+
+ if (!list_empty_careful(&wait->task_list)) {
+ raw_spin_lock_irqsave(&q->lock, flags);
+ list_del_init(&wait->task_list);
+ raw_spin_unlock_irqrestore(&q->lock, flags);
+ }
+}
+EXPORT_SYMBOL(finish_swait);