1) # of times sched_yield() was called
Next three are schedule() statistics:
- 2) # of times we switched to the expired queue and reused it
+ 2) This field is a legacy array expiration count field used in the O(1)
+ scheduler. We kept it for ABI compatibility, but it is always set to zero.
3) # of times schedule() was called
4) # of times schedule() left the processor idle
PERFORMANCE EVENTS SUBSYSTEM
M: Peter Zijlstra <a.p.zijlstra@chello.nl>
M: Paul Mackerras <paulus@samba.org>
-M: Ingo Molnar <mingo@elte.hu>
+M: Ingo Molnar <mingo@redhat.com>
M: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/core
S: Supported
F: drivers/watchdog/sc1200wdt.c
SCHEDULER
-M: Ingo Molnar <mingo@elte.hu>
+M: Ingo Molnar <mingo@redhat.com>
M: Peter Zijlstra <peterz@infradead.org>
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core
S: Maintained
leds_event(led_idle_end);
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
*/
percpu_timer_setup();
- while (!cpu_active(cpu))
- cpu_relax();
-
- /*
- * cpu_active bit is set, so it's safe to enalbe interrupts
- * now.
- */
local_irq_enable();
local_fiq_enable();
cpu_idle_sleep();
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
idle();
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
idle = default_idle;
idle();
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
idle();
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
while (1) {
while (!need_resched())
idle();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu);
set_cpu_online(cpu, true);
- while (!cpumask_test_cpu(cpu, cpu_active_mask))
- cpu_relax();
local_irq_enable();
cpu_idle();
normal_xtp();
#endif
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
check_pgt_cache();
if (cpu_is_offline(cpu))
play_dead();
idle();
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
while (1) {
while (!need_resched())
idle();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
/* endless idle loop with no priority at all */
while (1) {
idle();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
check_pgt_cache();
}
}
#endif
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
idle();
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
while (1) {
while (!need_resched())
barrier();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
check_pgt_cache();
}
}
ppc64_runlatch_on();
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- if (cpu_should_die())
+ if (cpu_should_die()) {
+ sched_preempt_enable_no_resched();
cpu_die();
- schedule();
- preempt_disable();
+ }
+ schedule_preempt_disabled();
}
}
if (hvlpevent_is_pending())
process_iSeries_events();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
ppc64_runlatch_on();
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
tick_nohz_idle_exit();
if (test_thread_flag(TIF_MCCK_PENDING))
s390_handle_mcck();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
S390_lowcore.restart_psw.addr =
PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
__ctl_set_bit(0, 28); /* Enable lowcore protection */
- /*
- * Wait until the cpu which brought this one up marked it
- * active before enabling interrupts.
- */
- while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
- cpu_relax();
local_irq_enable();
/* cpu_idle will call schedule for us */
cpu_idle();
while (!need_resched())
barrier();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
while (!need_resched())
cpu_relax();
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
check_pgt_cache();
}
}
while (!need_resched())
cpu_relax();
}
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
check_pgt_cache();
}
}
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
-
#ifdef CONFIG_HOTPLUG_CPU
- if (cpu_is_offline(cpu))
+ if (cpu_is_offline(cpu)) {
+ sched_preempt_enable_no_resched();
cpu_play_dead();
+ }
#endif
-
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
}
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
static inline unsigned long long __cycles_2_ns(unsigned long long cyc)
{
- unsigned long long quot;
- unsigned long long rem;
int cpu = smp_processor_id();
unsigned long long ns = per_cpu(cyc2ns_offset, cpu);
- quot = (cyc >> CYC2NS_SCALE_FACTOR);
- rem = cyc & ((1ULL << CYC2NS_SCALE_FACTOR) - 1);
- ns += quot * per_cpu(cyc2ns, cpu) +
- ((rem * per_cpu(cyc2ns, cpu)) >> CYC2NS_SCALE_FACTOR);
+ ns += mult_frac(cyc, per_cpu(cyc2ns, cpu),
+ (1UL << CYC2NS_SCALE_FACTOR));
return ns;
}
}
rcu_idle_exit();
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
}
tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
* Update loops_per_jiffy in cpu_data. Previous call to
* smp_store_cpu_info() stored a value that is close but not as
* accurate as the value just calculated.
- *
- * Need to enable IRQs because it can take longer and then
- * the NMI watchdog might kill us.
*/
- local_irq_enable();
calibrate_delay();
cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
- local_irq_disable();
pr_debug("Stack at about %p\n", &cpuid);
/*
per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
x86_platform.nmi_init();
- /*
- * Wait until the cpu which brought this one up marked it
- * online before enabling interrupts. If we don't do that then
- * we can end up waking up the softirq thread before this cpu
- * reached the active state, which makes the scheduler unhappy
- * and schedule the softirq thread on the wrong cpu. This is
- * only observable with forced threaded interrupts, but in
- * theory it could also happen w/o them. It's just way harder
- * to achieve.
- */
- while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
- cpu_relax();
-
/* enable local interrupts */
local_irq_enable();
if (cpu_khz) {
*scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
- *offset = ns_now - (tsc_now * *scale >> CYC2NS_SCALE_FACTOR);
+ *offset = ns_now - mult_frac(tsc_now, *scale,
+ (1UL << CYC2NS_SCALE_FACTOR));
}
sched_clock_idle_wakeup_event(0);
while (1) {
while (!need_resched())
platform_idle();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
}
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
+#include <linux/sched.h>
#include "blk.h"
void __blk_complete_request(struct request *req)
{
- int ccpu, cpu, group_cpu = NR_CPUS;
+ int ccpu, cpu;
struct request_queue *q = req->q;
unsigned long flags;
+ bool shared = false;
BUG_ON(!q->softirq_done_fn);
*/
if (req->cpu != -1) {
ccpu = req->cpu;
- if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) {
- ccpu = blk_cpu_to_group(ccpu);
- group_cpu = blk_cpu_to_group(cpu);
- }
+ if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags))
+ shared = cpus_share_cache(cpu, ccpu);
} else
ccpu = cpu;
/*
- * If current CPU and requested CPU are in the same group, running
- * softirq in current CPU. One might concern this is just like
+ * If current CPU and requested CPU share a cache, run the softirq on
+ * the current CPU. One might concern this is just like
* QUEUE_FLAG_SAME_FORCE, but actually not. blk_complete_request() is
* running in interrupt handler, and currently I/O controller doesn't
* support multiple interrupts, so current CPU is unique actually. This
* avoids IPI sending from current CPU to the first CPU of a group.
*/
- if (ccpu == cpu || ccpu == group_cpu) {
+ if (ccpu == cpu || shared) {
struct list_head *list;
do_local:
list = &__get_cpu_var(blk_cpu_done);
return q->nr_congestion_off;
}
-static inline int blk_cpu_to_group(int cpu)
-{
- int group = NR_CPUS;
-#ifdef CONFIG_SCHED_MC
- const struct cpumask *mask = cpu_coregroup_mask(cpu);
- group = cpumask_first(mask);
-#elif defined(CONFIG_SCHED_SMT)
- group = cpumask_first(topology_thread_cpumask(cpu));
-#else
- return cpu;
-#endif
- if (likely(group < NR_CPUS))
- return group;
- return cpu;
-}
-
/*
* Contribute to IO statistics IFF:
*
if (!p)
return -ESRCH;
- err = nice;
- err = proc_sched_autogroup_set_nice(p, &err);
+ err = proc_sched_autogroup_set_nice(p, nice);
if (err)
count = err;
extern void cpuset_init_smp(void);
extern void cpuset_update_active_cpus(void);
extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
-extern int cpuset_cpus_allowed_fallback(struct task_struct *p);
+extern void cpuset_cpus_allowed_fallback(struct task_struct *p);
extern nodemask_t cpuset_mems_allowed(struct task_struct *p);
#define cpuset_current_mems_allowed (current->mems_allowed)
void cpuset_init_current_mems_allowed(void);
cpumask_copy(mask, cpu_possible_mask);
}
-static inline int cpuset_cpus_allowed_fallback(struct task_struct *p)
+static inline void cpuset_cpus_allowed_fallback(struct task_struct *p)
{
- do_set_cpus_allowed(p, cpu_possible_mask);
- return cpumask_any(cpu_active_mask);
}
static inline nodemask_t cpuset_mems_allowed(struct task_struct *p)
}, \
.rt = { \
.run_list = LIST_HEAD_INIT(tsk.rt.run_list), \
- .time_slice = HZ, \
+ .time_slice = RR_TIMESLICE, \
.nr_cpus_allowed = NR_CPUS, \
}, \
.tasks = LIST_HEAD_INIT(tsk.tasks), \
} \
)
+/*
+ * Multiplies an integer by a fraction, while avoiding unnecessary
+ * overflow or loss of precision.
+ */
+#define mult_frac(x, numer, denom)( \
+{ \
+ typeof(x) quot = (x) / (denom); \
+ typeof(x) rem = (x) % (denom); \
+ (quot * (numer)) + ((rem * (numer)) / (denom)); \
+} \
+)
+
+
#define _RET_IP_ (unsigned long)__builtin_return_address(0)
#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
barrier(); \
} while (0)
-#define preempt_enable_no_resched() \
+#define sched_preempt_enable_no_resched() \
do { \
barrier(); \
dec_preempt_count(); \
} while (0)
+#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+
#define preempt_enable() \
do { \
preempt_enable_no_resched(); \
#else /* !CONFIG_PREEMPT_COUNT */
#define preempt_disable() do { } while (0)
+#define sched_preempt_enable_no_resched() do { } while (0)
#define preempt_enable_no_resched() do { } while (0)
#define preempt_enable() do { } while (0)
int printk(const char *fmt, ...);
/*
+ * Special printk facility for scheduler use only, _DO_NOT_USE_ !
+ */
+__printf(1, 2) __cold int printk_sched(const char *fmt, ...);
+
+/*
* Please don't use printk_ratelimit(), because it shares ratelimiting state
* with all other unrelated printk_ratelimit() callsites. Instead use
* printk_ratelimited() or plain old __ratelimit().
{
return 0;
}
+static inline __printf(1, 2) __cold
+int printk_sched(const char *s, ...)
+{
+ return 0;
+}
static inline int printk_ratelimit(void)
{
return 0;
extern signed long schedule_timeout_killable(signed long timeout);
extern signed long schedule_timeout_uninterruptible(signed long timeout);
asmlinkage void schedule(void);
+extern void schedule_preempt_disabled(void);
extern int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner);
struct nsproxy;
* single CPU.
*/
unsigned int power, power_orig;
+ unsigned long next_update;
/*
* Number of busy cpus in this group.
*/
unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
+bool cpus_share_cache(int this_cpu, int that_cpu);
+
#else /* CONFIG_SMP */
struct sched_domain_attr;
struct sched_domain_attr *dattr_new)
{
}
+
+static inline bool cpus_share_cache(int this_cpu, int that_cpu)
+{
+ return true;
+}
+
#endif /* !CONFIG_SMP */
#endif
};
+/*
+ * default timeslice is 100 msecs (used only for SCHED_RR tasks).
+ * Timeslices get refilled after they expire.
+ */
+#define RR_TIMESLICE (100 * HZ / 1000)
+
struct rcu_node;
enum perf_event_task_context {
extern void sched_autogroup_exit(struct signal_struct *sig);
#ifdef CONFIG_PROC_FS
extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m);
-extern int proc_sched_autogroup_set_nice(struct task_struct *p, int *nice);
+extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice);
#endif
#else
static inline void sched_autogroup_create_attach(struct task_struct *p) { }
extern int rt_mutex_getprio(struct task_struct *p);
extern void rt_mutex_setprio(struct task_struct *p, int prio);
extern void rt_mutex_adjust_pi(struct task_struct *p);
+static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
+{
+ return tsk->pi_blocked_on != NULL;
+}
#else
static inline int rt_mutex_getprio(struct task_struct *p)
{
return p->normal_prio;
}
# define rt_mutex_adjust_pi(p) do { } while (0)
+static inline bool tsk_is_pi_blocked(struct task_struct *tsk)
+{
+ return false;
+}
#endif
extern bool yield_to(struct task_struct *p, bool preempt);
extern struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
unsigned long *flags);
-#define lock_task_sighand(tsk, flags) \
-({ struct sighand_struct *__ss; \
- __cond_lock(&(tsk)->sighand->siglock, \
- (__ss = __lock_task_sighand(tsk, flags))); \
- __ss; \
-}) \
+static inline struct sighand_struct *lock_task_sighand(struct task_struct *tsk,
+ unsigned long *flags)
+{
+ struct sighand_struct *ret;
+
+ ret = __lock_task_sighand(tsk, flags);
+ (void)__cond_lock(&tsk->sighand->siglock, ret);
+ return ret;
+}
static inline void unlock_task_sighand(struct task_struct *tsk,
unsigned long *flags)
void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
void *key);
-void __wake_up_locked(wait_queue_head_t *q, unsigned int mode);
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
void __wake_up_bit(wait_queue_head_t *, void *, int);
int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
-#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL)
+#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
+#define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
* at least once to get things moving:
*/
init_idle_bootup_task(current);
- preempt_enable_no_resched();
- schedule();
-
+ schedule_preempt_disabled();
/* Call into cpu_idle with preempt disabled */
- preempt_disable();
cpu_idle();
}
mutex_unlock(&callback_mutex);
}
-int cpuset_cpus_allowed_fallback(struct task_struct *tsk)
+void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
{
const struct cpuset *cs;
- int cpu;
rcu_read_lock();
cs = task_cs(tsk);
* changes in tsk_cs()->cpus_allowed. Otherwise we can temporary
* set any mask even if it is not right from task_cs() pov,
* the pending set_cpus_allowed_ptr() will fix things.
+ *
+ * select_fallback_rq() will fix things ups and set cpu_possible_mask
+ * if required.
*/
-
- cpu = cpumask_any_and(&tsk->cpus_allowed, cpu_active_mask);
- if (cpu >= nr_cpu_ids) {
- /*
- * Either tsk->cpus_allowed is wrong (see above) or it
- * is actually empty. The latter case is only possible
- * if we are racing with remove_tasks_in_empty_cpuset().
- * Like above we can temporary set any mask and rely on
- * set_cpus_allowed_ptr() as synchronization point.
- */
- do_set_cpus_allowed(tsk, cpu_possible_mask);
- cpu = cpumask_any(cpu_active_mask);
- }
-
- return cpu;
}
void cpuset_init_current_mems_allowed(void)
/* didn't get the lock, go to sleep: */
spin_unlock_mutex(&lock->wait_lock, flags);
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
spin_lock_mutex(&lock->wait_lock, flags);
}
return console_locked;
}
+/*
+ * Delayed printk facility, for scheduler-internal messages:
+ */
+#define PRINTK_BUF_SIZE 512
+
+#define PRINTK_PENDING_WAKEUP 0x01
+#define PRINTK_PENDING_SCHED 0x02
+
static DEFINE_PER_CPU(int, printk_pending);
+static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
void printk_tick(void)
{
if (__this_cpu_read(printk_pending)) {
- __this_cpu_write(printk_pending, 0);
- wake_up_interruptible(&log_wait);
+ int pending = __this_cpu_xchg(printk_pending, 0);
+ if (pending & PRINTK_PENDING_SCHED) {
+ char *buf = __get_cpu_var(printk_sched_buf);
+ printk(KERN_WARNING "[sched_delayed] %s", buf);
+ }
+ if (pending & PRINTK_PENDING_WAKEUP)
+ wake_up_interruptible(&log_wait);
}
}
void wake_up_klogd(void)
{
if (waitqueue_active(&log_wait))
- this_cpu_write(printk_pending, 1);
+ this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
}
/**
#if defined CONFIG_PRINTK
+int printk_sched(const char *fmt, ...)
+{
+ unsigned long flags;
+ va_list args;
+ char *buf;
+ int r;
+
+ local_irq_save(flags);
+ buf = __get_cpu_var(printk_sched_buf);
+
+ va_start(args, fmt);
+ r = vsnprintf(buf, PRINTK_BUF_SIZE, fmt, args);
+ va_end(args);
+
+ __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+ local_irq_restore(flags);
+
+ return r;
+}
+
/*
* printk rate limiting, lifted from the networking subsystem.
*
#ifdef CONFIG_PROC_FS
-int proc_sched_autogroup_set_nice(struct task_struct *p, int *nice)
+int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
{
static unsigned long next = INITIAL_JIFFIES;
struct autogroup *ag;
int err;
- if (*nice < -20 || *nice > 19)
+ if (nice < -20 || nice > 19)
return -EINVAL;
- err = security_task_setnice(current, *nice);
+ err = security_task_setnice(current, nice);
if (err)
return err;
- if (*nice < 0 && !can_nice(current, *nice))
+ if (nice < 0 && !can_nice(current, nice))
return -EPERM;
/* this is a heavy operation taking global locks.. */
ag = autogroup_task_get(p);
down_write(&ag->lock);
- err = sched_group_set_shares(ag->tg, prio_to_weight[*nice + 20]);
+ err = sched_group_set_shares(ag->tg, prio_to_weight[nice + 20]);
if (!err)
- ag->nice = *nice;
+ ag->nice = nice;
up_write(&ag->lock);
autogroup_kref_put(ag);
*/
static int select_fallback_rq(int cpu, struct task_struct *p)
{
- int dest_cpu;
const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+ enum { cpuset, possible, fail } state = cpuset;
+ int dest_cpu;
/* Look for allowed, online CPU in same node. */
- for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
+ for_each_cpu_mask(dest_cpu, *nodemask) {
+ if (!cpu_online(dest_cpu))
+ continue;
+ if (!cpu_active(dest_cpu))
+ continue;
if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
return dest_cpu;
+ }
+
+ for (;;) {
+ /* Any allowed, online CPU? */
+ for_each_cpu_mask(dest_cpu, *tsk_cpus_allowed(p)) {
+ if (!cpu_online(dest_cpu))
+ continue;
+ if (!cpu_active(dest_cpu))
+ continue;
+ goto out;
+ }
- /* Any allowed, online CPU? */
- dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask);
- if (dest_cpu < nr_cpu_ids)
- return dest_cpu;
+ switch (state) {
+ case cpuset:
+ /* No more Mr. Nice Guy. */
+ cpuset_cpus_allowed_fallback(p);
+ state = possible;
+ break;
- /* No more Mr. Nice Guy. */
- dest_cpu = cpuset_cpus_allowed_fallback(p);
- /*
- * Don't tell them about moving exiting tasks or
- * kernel threads (both mm NULL), since they never
- * leave kernel.
- */
- if (p->mm && printk_ratelimit()) {
- printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n",
- task_pid_nr(p), p->comm, cpu);
+ case possible:
+ do_set_cpus_allowed(p, cpu_possible_mask);
+ state = fail;
+ break;
+
+ case fail:
+ BUG();
+ break;
+ }
+ }
+
+out:
+ if (state != cpuset) {
+ /*
+ * Don't tell them about moving exiting tasks or
+ * kernel threads (both mm NULL), since they never
+ * leave kernel.
+ */
+ if (p->mm && printk_ratelimit()) {
+ printk_sched("process %d (%s) no longer affine to cpu%d\n",
+ task_pid_nr(p), p->comm, cpu);
+ }
}
return dest_cpu;
}
#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
-static inline int ttwu_share_cache(int this_cpu, int that_cpu)
+bool cpus_share_cache(int this_cpu, int that_cpu)
{
return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);
}
struct rq *rq = cpu_rq(cpu);
#if defined(CONFIG_SMP)
- if (sched_feat(TTWU_QUEUE) && !ttwu_share_cache(smp_processor_id(), cpu)) {
+ if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) {
sched_clock_cpu(cpu); /* sync clocks x-cpu */
ttwu_queue_remote(p, cpu);
return;
* Once we've updated the global active value, we need to apply the exponential
* weights adjusted to the number of cycles missed.
*/
-static void calc_global_nohz(unsigned long ticks)
+static void calc_global_nohz(void)
{
long delta, active, n;
- if (time_before(jiffies, calc_load_update))
- return;
-
/*
* If we crossed a calc_load_update boundary, make sure to fold
* any pending idle changes, the respective CPUs might have
atomic_long_add(delta, &calc_load_tasks);
/*
- * If we were idle for multiple load cycles, apply them.
+ * It could be the one fold was all it took, we done!
*/
- if (ticks >= LOAD_FREQ) {
- n = ticks / LOAD_FREQ;
+ if (time_before(jiffies, calc_load_update + 10))
+ return;
- active = atomic_long_read(&calc_load_tasks);
- active = active > 0 ? active * FIXED_1 : 0;
+ /*
+ * Catch-up, fold however many we are behind still
+ */
+ delta = jiffies - calc_load_update - 10;
+ n = 1 + (delta / LOAD_FREQ);
- avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
- avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
- avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
+ active = atomic_long_read(&calc_load_tasks);
+ active = active > 0 ? active * FIXED_1 : 0;
- calc_load_update += n * LOAD_FREQ;
- }
+ avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
+ avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
+ avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
- /*
- * Its possible the remainder of the above division also crosses
- * a LOAD_FREQ period, the regular check in calc_global_load()
- * which comes after this will take care of that.
- *
- * Consider us being 11 ticks before a cycle completion, and us
- * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will
- * age us 4 cycles, and the test in calc_global_load() will
- * pick up the final one.
- */
+ calc_load_update += n * LOAD_FREQ;
}
#else
void calc_load_account_idle(struct rq *this_rq)
return 0;
}
-static void calc_global_nohz(unsigned long ticks)
+static void calc_global_nohz(void)
{
}
#endif
{
long active;
- calc_global_nohz(ticks);
-
if (time_before(jiffies, calc_load_update + 10))
return;
avenrun[2] = calc_load(avenrun[2], EXP_15, active);
calc_load_update += LOAD_FREQ;
+
+ /*
+ * Account one period with whatever state we found before
+ * folding in the nohz state and ageing the entire idle period.
+ *
+ * This avoids loosing a sample when we go idle between
+ * calc_load_account_active() (10 ticks ago) and now and thus
+ * under-accounting.
+ */
+ calc_global_nohz();
}
/*
*/
static noinline void __schedule_bug(struct task_struct *prev)
{
- struct pt_regs *regs = get_irq_regs();
-
if (oops_in_progress)
return;
print_modules();
if (irqs_disabled())
print_irqtrace_events(prev);
-
- if (regs)
- show_regs(regs);
- else
- dump_stack();
+ dump_stack();
}
/*
post_schedule(rq);
- preempt_enable_no_resched();
+ sched_preempt_enable_no_resched();
if (need_resched())
goto need_resched;
}
static inline void sched_submit_work(struct task_struct *tsk)
{
- if (!tsk->state)
+ if (!tsk->state || tsk_is_pi_blocked(tsk))
return;
/*
* If we are going to sleep and we have plugged IO queued,
}
EXPORT_SYMBOL(schedule);
+/**
+ * schedule_preempt_disabled - called with preemption disabled
+ *
+ * Returns with preemption disabled. Note: preempt_count must be 1
+ */
+void __sched schedule_preempt_disabled(void)
+{
+ sched_preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+}
+
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
/*
* Same as __wake_up but called with the spinlock in wait_queue_head_t held.
*/
-void __wake_up_locked(wait_queue_head_t *q, unsigned int mode)
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
{
- __wake_up_common(q, mode, 1, 0, NULL);
+ __wake_up_common(q, mode, nr, 0, NULL);
}
EXPORT_SYMBOL_GPL(__wake_up_locked);
rq = __task_rq_lock(p);
+ /*
+ * Idle task boosting is a nono in general. There is one
+ * exception, when PREEMPT_RT and NOHZ is active:
+ *
+ * The idle task calls get_next_timer_interrupt() and holds
+ * the timer wheel base->lock on the CPU and another CPU wants
+ * to access the timer (probably to cancel it). We can safely
+ * ignore the boosting request, as the idle CPU runs this code
+ * with interrupts disabled and will complete the lock
+ * protected section without being interrupted. So there is no
+ * real need to boost.
+ */
+ if (unlikely(p == rq->idle)) {
+ WARN_ON(p != rq->curr);
+ WARN_ON(p->pi_blocked_on);
+ goto out_unlock;
+ }
+
trace_sched_pi_setprio(p, prio);
oldprio = p->prio;
prev_class = p->sched_class;
enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
check_class_changed(rq, p, prev_class, oldprio);
+out_unlock:
__task_rq_unlock(rq);
}
-
#endif
-
void set_user_nice(struct task_struct *p, long nice)
{
int old_prio, delta, on_rq;
__release(rq->lock);
spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
do_raw_spin_unlock(&rq->lock);
- preempt_enable_no_resched();
+ sched_preempt_enable_no_resched();
schedule();
/**
* yield - yield the current processor to other threads.
*
- * This is a shortcut for kernel-space yielding - it marks the
- * thread runnable and calls sys_sched_yield().
+ * Do not ever use this function, there's a 99% chance you're doing it wrong.
+ *
+ * The scheduler is at all times free to pick the calling task as the most
+ * eligible task to run, if removing the yield() call from your code breaks
+ * it, its already broken.
+ *
+ * Typical broken usage is:
+ *
+ * while (!event)
+ * yield();
+ *
+ * where one assumes that yield() will let 'the other' process run that will
+ * make event true. If the current task is a SCHED_FIFO task that will never
+ * happen. Never use yield() as a progress guarantee!!
+ *
+ * If you want to use yield() to wait for something, use wait_event().
+ * If you want to use yield() to be 'nice' for others, use cond_resched().
+ * If you still want to use yield(), do not!
*/
void __sched yield(void)
{
unsigned long action, void *hcpu)
{
switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_ONLINE:
+ case CPU_STARTING:
case CPU_DOWN_FAILED:
set_cpu_active((long)hcpu, true);
return NOTIFY_OK;
*
* Also keep a unique ID per domain (we use the first cpu number in
* the cpumask of the domain), this allows us to quickly tell if
- * two cpus are in the same cache domain, see ttwu_share_cache().
+ * two cpus are in the same cache domain, see cpus_share_cache().
*/
DEFINE_PER_CPU(struct sched_domain *, sd_llc);
DEFINE_PER_CPU(int, sd_llc_id);
rq->online = 0;
rq->idle_stamp = 0;
rq->avg_idle = 2*sysctl_sched_migration_cost;
+
+ INIT_LIST_HEAD(&rq->cfs_tasks);
+
rq_attach_root(rq, &def_root_domain);
#ifdef CONFIG_NO_HZ
rq->nohz_flags = 0;
P(yld_count);
- P(sched_switch);
P(sched_count);
P(sched_goidle);
#ifdef CONFIG_SMP
#endif /* CONFIG_FAIR_GROUP_SCHED */
-static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
- unsigned long delta_exec);
+static __always_inline
+void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec);
/**************************************************************
* Scheduling class tree data structure manipulation methods:
* Scheduling class queueing methods:
*/
-#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
-static void
-add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
-{
- cfs_rq->task_weight += weight;
-}
-#else
-static inline void
-add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
-{
-}
-#endif
-
static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
update_load_add(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
- if (entity_is_task(se)) {
- add_cfs_task_weight(cfs_rq, se->load.weight);
- list_add(&se->group_node, &cfs_rq->tasks);
- }
+#ifdef CONFIG_SMP
+ if (entity_is_task(se))
+ list_add_tail(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
+#endif
cfs_rq->nr_running++;
}
update_load_sub(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
- if (entity_is_task(se)) {
- add_cfs_task_weight(cfs_rq, -se->load.weight);
+ if (entity_is_task(se))
list_del_init(&se->group_node);
- }
cfs_rq->nr_running--;
}
__clear_buddies_skip(se);
}
-static void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
+static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
resched_task(rq_of(cfs_rq)->curr);
}
-static __always_inline void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
- unsigned long delta_exec)
+static __always_inline
+void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec)
{
if (!cfs_bandwidth_used() || !cfs_rq->runtime_enabled)
return;
}
#else /* CONFIG_CFS_BANDWIDTH */
-static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
- unsigned long delta_exec) {}
+static __always_inline
+void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec) {}
static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
-static void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
+static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
{
/*
* Otherwise, iterate the domains and find an elegible idle cpu.
*/
- rcu_read_lock();
-
sd = rcu_dereference(per_cpu(sd_llc, target));
for_each_lower_domain(sd) {
sg = sd->groups;
} while (sg != sd->groups);
}
done:
- rcu_read_unlock();
-
return target;
}
return;
/*
- * This is possible from callers such as pull_task(), in which we
+ * This is possible from callers such as move_task(), in which we
* unconditionally check_prempt_curr() after an enqueue (which may have
* lead to a throttle). This both saves work and prevents false
* next-buddy nomination below.
* Fair scheduling class load-balancing methods:
*/
+static unsigned long __read_mostly max_load_balance_interval = HZ/10;
+
+#define LBF_ALL_PINNED 0x01
+#define LBF_NEED_BREAK 0x02
+
+struct lb_env {
+ struct sched_domain *sd;
+
+ int src_cpu;
+ struct rq *src_rq;
+
+ int dst_cpu;
+ struct rq *dst_rq;
+
+ enum cpu_idle_type idle;
+ long load_move;
+ unsigned int flags;
+
+ unsigned int loop;
+ unsigned int loop_break;
+ unsigned int loop_max;
+};
+
/*
- * pull_task - move a task from a remote runqueue to the local runqueue.
+ * move_task - move a task from one runqueue to another runqueue.
* Both runqueues must be locked.
*/
-static void pull_task(struct rq *src_rq, struct task_struct *p,
- struct rq *this_rq, int this_cpu)
+static void move_task(struct task_struct *p, struct lb_env *env)
{
- deactivate_task(src_rq, p, 0);
- set_task_cpu(p, this_cpu);
- activate_task(this_rq, p, 0);
- check_preempt_curr(this_rq, p, 0);
+ deactivate_task(env->src_rq, p, 0);
+ set_task_cpu(p, env->dst_cpu);
+ activate_task(env->dst_rq, p, 0);
+ check_preempt_curr(env->dst_rq, p, 0);
}
/*
return delta < (s64)sysctl_sched_migration_cost;
}
-#define LBF_ALL_PINNED 0x01
-#define LBF_NEED_BREAK 0x02 /* clears into HAD_BREAK */
-#define LBF_HAD_BREAK 0x04
-#define LBF_HAD_BREAKS 0x0C /* count HAD_BREAKs overflows into ABORT */
-#define LBF_ABORT 0x10
-
/*
* can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
*/
static
-int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *lb_flags)
+int can_migrate_task(struct task_struct *p, struct lb_env *env)
{
int tsk_cache_hot = 0;
/*
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) are cache-hot on their current CPU.
*/
- if (!cpumask_test_cpu(this_cpu, tsk_cpus_allowed(p))) {
+ if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) {
schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
return 0;
}
- *lb_flags &= ~LBF_ALL_PINNED;
+ env->flags &= ~LBF_ALL_PINNED;
- if (task_running(rq, p)) {
+ if (task_running(env->src_rq, p)) {
schedstat_inc(p, se.statistics.nr_failed_migrations_running);
return 0;
}
* 2) too many balance attempts have failed.
*/
- tsk_cache_hot = task_hot(p, rq->clock_task, sd);
+ tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd);
if (!tsk_cache_hot ||
- sd->nr_balance_failed > sd->cache_nice_tries) {
+ env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
if (tsk_cache_hot) {
- schedstat_inc(sd, lb_hot_gained[idle]);
+ schedstat_inc(env->sd, lb_hot_gained[env->idle]);
schedstat_inc(p, se.statistics.nr_forced_migrations);
}
#endif
*
* Called with both runqueues locked.
*/
-static int
-move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
- struct sched_domain *sd, enum cpu_idle_type idle)
+static int move_one_task(struct lb_env *env)
{
struct task_struct *p, *n;
- struct cfs_rq *cfs_rq;
- int pinned = 0;
- for_each_leaf_cfs_rq(busiest, cfs_rq) {
- list_for_each_entry_safe(p, n, &cfs_rq->tasks, se.group_node) {
- if (throttled_lb_pair(task_group(p),
- busiest->cpu, this_cpu))
- break;
+ list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
+ if (throttled_lb_pair(task_group(p), env->src_rq->cpu, env->dst_cpu))
+ continue;
- if (!can_migrate_task(p, busiest, this_cpu,
- sd, idle, &pinned))
- continue;
+ if (!can_migrate_task(p, env))
+ continue;
- pull_task(busiest, p, this_rq, this_cpu);
- /*
- * Right now, this is only the second place pull_task()
- * is called, so we can safely collect pull_task()
- * stats here rather than inside pull_task().
- */
- schedstat_inc(sd, lb_gained[idle]);
- return 1;
- }
+ move_task(p, env);
+ /*
+ * Right now, this is only the second place move_task()
+ * is called, so we can safely collect move_task()
+ * stats here rather than inside move_task().
+ */
+ schedstat_inc(env->sd, lb_gained[env->idle]);
+ return 1;
}
-
return 0;
}
-static unsigned long
-balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move, struct sched_domain *sd,
- enum cpu_idle_type idle, int *lb_flags,
- struct cfs_rq *busiest_cfs_rq)
+static unsigned long task_h_load(struct task_struct *p);
+
+/*
+ * move_tasks tries to move up to load_move weighted load from busiest to
+ * this_rq, as part of a balancing operation within domain "sd".
+ * Returns 1 if successful and 0 otherwise.
+ *
+ * Called with both runqueues locked.
+ */
+static int move_tasks(struct lb_env *env)
{
- int loops = 0, pulled = 0;
- long rem_load_move = max_load_move;
- struct task_struct *p, *n;
+ struct list_head *tasks = &env->src_rq->cfs_tasks;
+ struct task_struct *p;
+ unsigned long load;
+ int pulled = 0;
+
+ if (env->load_move <= 0)
+ return 0;
- if (max_load_move == 0)
- goto out;
+ while (!list_empty(tasks)) {
+ p = list_first_entry(tasks, struct task_struct, se.group_node);
- list_for_each_entry_safe(p, n, &busiest_cfs_rq->tasks, se.group_node) {
- if (loops++ > sysctl_sched_nr_migrate) {
- *lb_flags |= LBF_NEED_BREAK;
+ env->loop++;
+ /* We've more or less seen every task there is, call it quits */
+ if (env->loop > env->loop_max)
+ break;
+
+ /* take a breather every nr_migrate tasks */
+ if (env->loop > env->loop_break) {
+ env->loop_break += sysctl_sched_nr_migrate;
+ env->flags |= LBF_NEED_BREAK;
break;
}
- if ((p->se.load.weight >> 1) > rem_load_move ||
- !can_migrate_task(p, busiest, this_cpu, sd, idle,
- lb_flags))
- continue;
+ if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
+ goto next;
+
+ load = task_h_load(p);
+
+ if (load < 16 && !env->sd->nr_balance_failed)
+ goto next;
+
+ if ((load / 2) > env->load_move)
+ goto next;
- pull_task(busiest, p, this_rq, this_cpu);
+ if (!can_migrate_task(p, env))
+ goto next;
+
+ move_task(p, env);
pulled++;
- rem_load_move -= p->se.load.weight;
+ env->load_move -= load;
#ifdef CONFIG_PREEMPT
/*
* kernels will stop after the first task is pulled to minimize
* the critical section.
*/
- if (idle == CPU_NEWLY_IDLE) {
- *lb_flags |= LBF_ABORT;
+ if (env->idle == CPU_NEWLY_IDLE)
break;
- }
#endif
/*
* We only want to steal up to the prescribed amount of
* weighted load.
*/
- if (rem_load_move <= 0)
+ if (env->load_move <= 0)
break;
+
+ continue;
+next:
+ list_move_tail(&p->se.group_node, tasks);
}
-out:
+
/*
- * Right now, this is one of only two places pull_task() is called,
- * so we can safely collect pull_task() stats here rather than
- * inside pull_task().
+ * Right now, this is one of only two places move_task() is called,
+ * so we can safely collect move_task() stats here rather than
+ * inside move_task().
*/
- schedstat_add(sd, lb_gained[idle], pulled);
+ schedstat_add(env->sd, lb_gained[env->idle], pulled);
- return max_load_move - rem_load_move;
+ return pulled;
}
#ifdef CONFIG_FAIR_GROUP_SCHED
static void update_h_load(long cpu)
{
+ rcu_read_lock();
walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
+ rcu_read_unlock();
}
-static unsigned long
-load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *lb_flags)
+static unsigned long task_h_load(struct task_struct *p)
{
- long rem_load_move = max_load_move;
- struct cfs_rq *busiest_cfs_rq;
-
- rcu_read_lock();
- update_h_load(cpu_of(busiest));
-
- for_each_leaf_cfs_rq(busiest, busiest_cfs_rq) {
- unsigned long busiest_h_load = busiest_cfs_rq->h_load;
- unsigned long busiest_weight = busiest_cfs_rq->load.weight;
- u64 rem_load, moved_load;
-
- if (*lb_flags & (LBF_NEED_BREAK|LBF_ABORT))
- break;
-
- /*
- * empty group or part of a throttled hierarchy
- */
- if (!busiest_cfs_rq->task_weight ||
- throttled_lb_pair(busiest_cfs_rq->tg, cpu_of(busiest), this_cpu))
- continue;
-
- rem_load = (u64)rem_load_move * busiest_weight;
- rem_load = div_u64(rem_load, busiest_h_load + 1);
-
- moved_load = balance_tasks(this_rq, this_cpu, busiest,
- rem_load, sd, idle, lb_flags,
- busiest_cfs_rq);
-
- if (!moved_load)
- continue;
+ struct cfs_rq *cfs_rq = task_cfs_rq(p);
+ unsigned long load;
- moved_load *= busiest_h_load;
- moved_load = div_u64(moved_load, busiest_weight + 1);
+ load = p->se.load.weight;
+ load = div_u64(load * cfs_rq->h_load, cfs_rq->load.weight + 1);
- rem_load_move -= moved_load;
- if (rem_load_move < 0)
- break;
- }
- rcu_read_unlock();
-
- return max_load_move - rem_load_move;
+ return load;
}
#else
static inline void update_shares(int cpu)
{
}
-static unsigned long
-load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *lb_flags)
+static inline void update_h_load(long cpu)
{
- return balance_tasks(this_rq, this_cpu, busiest,
- max_load_move, sd, idle, lb_flags,
- &busiest->cfs);
}
-#endif
-/*
- * move_tasks tries to move up to max_load_move weighted load from busiest to
- * this_rq, as part of a balancing operation within domain "sd".
- * Returns 1 if successful and 0 otherwise.
- *
- * Called with both runqueues locked.
- */
-static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *lb_flags)
+static unsigned long task_h_load(struct task_struct *p)
{
- unsigned long total_load_moved = 0, load_moved;
-
- do {
- load_moved = load_balance_fair(this_rq, this_cpu, busiest,
- max_load_move - total_load_moved,
- sd, idle, lb_flags);
-
- total_load_moved += load_moved;
-
- if (*lb_flags & (LBF_NEED_BREAK|LBF_ABORT))
- break;
-
-#ifdef CONFIG_PREEMPT
- /*
- * NEWIDLE balancing is a source of latency, so preemptible
- * kernels will stop after the first task is pulled to minimize
- * the critical section.
- */
- if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) {
- *lb_flags |= LBF_ABORT;
- break;
- }
-#endif
- } while (load_moved && max_load_move > total_load_moved);
-
- return total_load_moved > 0;
+ return p->se.load.weight;
}
+#endif
/********** Helpers for find_busiest_group ************************/
/*
struct sched_domain *child = sd->child;
struct sched_group *group, *sdg = sd->groups;
unsigned long power;
+ unsigned long interval;
+
+ interval = msecs_to_jiffies(sd->balance_interval);
+ interval = clamp(interval, 1UL, max_load_balance_interval);
+ sdg->sgp->next_update = jiffies + interval;
if (!child) {
update_cpu_power(sd, cpu);
* domains. In the newly idle case, we will allow all the cpu's
* to do the newly idle load balance.
*/
- if (idle != CPU_NEWLY_IDLE && local_group) {
- if (balance_cpu != this_cpu) {
- *balance = 0;
- return;
- }
- update_group_power(sd, this_cpu);
+ if (local_group) {
+ if (idle != CPU_NEWLY_IDLE) {
+ if (balance_cpu != this_cpu) {
+ *balance = 0;
+ return;
+ }
+ update_group_power(sd, this_cpu);
+ } else if (time_after_eq(jiffies, group->sgp->next_update))
+ update_group_power(sd, this_cpu);
}
/* Adjust by relative CPU power of the group */
struct sched_domain *sd, enum cpu_idle_type idle,
int *balance)
{
- int ld_moved, lb_flags = 0, active_balance = 0;
+ int ld_moved, active_balance = 0;
struct sched_group *group;
unsigned long imbalance;
struct rq *busiest;
unsigned long flags;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
+ struct lb_env env = {
+ .sd = sd,
+ .dst_cpu = this_cpu,
+ .dst_rq = this_rq,
+ .idle = idle,
+ .loop_break = sysctl_sched_nr_migrate,
+ };
+
cpumask_copy(cpus, cpu_active_mask);
schedstat_inc(sd, lb_count[idle]);
* still unbalanced. ld_moved simply stays zero, so it is
* correctly treated as an imbalance.
*/
- lb_flags |= LBF_ALL_PINNED;
+ env.flags |= LBF_ALL_PINNED;
+ env.load_move = imbalance;
+ env.src_cpu = busiest->cpu;
+ env.src_rq = busiest;
+ env.loop_max = busiest->nr_running;
+
+more_balance:
local_irq_save(flags);
double_rq_lock(this_rq, busiest);
- ld_moved = move_tasks(this_rq, this_cpu, busiest,
- imbalance, sd, idle, &lb_flags);
+ if (!env.loop)
+ update_h_load(env.src_cpu);
+ ld_moved += move_tasks(&env);
double_rq_unlock(this_rq, busiest);
local_irq_restore(flags);
+ if (env.flags & LBF_NEED_BREAK) {
+ env.flags &= ~LBF_NEED_BREAK;
+ goto more_balance;
+ }
+
/*
* some other cpu did the load balance for us.
*/
if (ld_moved && this_cpu != smp_processor_id())
resched_cpu(this_cpu);
- if (lb_flags & LBF_ABORT)
- goto out_balanced;
-
- if (lb_flags & LBF_NEED_BREAK) {
- lb_flags += LBF_HAD_BREAK - LBF_NEED_BREAK;
- if (lb_flags & LBF_ABORT)
- goto out_balanced;
- goto redo;
- }
-
/* All tasks on this runqueue were pinned by CPU affinity */
- if (unlikely(lb_flags & LBF_ALL_PINNED)) {
+ if (unlikely(env.flags & LBF_ALL_PINNED)) {
cpumask_clear_cpu(cpu_of(busiest), cpus);
if (!cpumask_empty(cpus))
goto redo;
tsk_cpus_allowed(busiest->curr))) {
raw_spin_unlock_irqrestore(&busiest->lock,
flags);
- lb_flags |= LBF_ALL_PINNED;
+ env.flags |= LBF_ALL_PINNED;
goto out_one_pinned;
}
out_one_pinned:
/* tune up the balancing interval */
- if (((lb_flags & LBF_ALL_PINNED) &&
+ if (((env.flags & LBF_ALL_PINNED) &&
sd->balance_interval < MAX_PINNED_INTERVAL) ||
(sd->balance_interval < sd->max_interval))
sd->balance_interval *= 2;
}
if (likely(sd)) {
+ struct lb_env env = {
+ .sd = sd,
+ .dst_cpu = target_cpu,
+ .dst_rq = target_rq,
+ .src_cpu = busiest_rq->cpu,
+ .src_rq = busiest_rq,
+ .idle = CPU_IDLE,
+ };
+
schedstat_inc(sd, alb_count);
- if (move_one_task(target_rq, target_cpu, busiest_rq,
- sd, CPU_IDLE))
+ if (move_one_task(&env))
schedstat_inc(sd, alb_pushed);
else
schedstat_inc(sd, alb_failed);
static DEFINE_SPINLOCK(balancing);
-static unsigned long __read_mostly max_load_balance_interval = HZ/10;
-
/*
* Scale the max load_balance interval with the number of CPUs in the system.
* This trades load-balance latency on larger machines for less cross talk.
void init_cfs_rq(struct cfs_rq *cfs_rq)
{
cfs_rq->tasks_timeline = RB_ROOT;
- INIT_LIST_HEAD(&cfs_rq->tasks);
cfs_rq->min_vruntime = (u64)(-(1LL << 20));
#ifndef CONFIG_64BIT
cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
#ifdef CONFIG_NO_HZ
+ nohz.next_balance = jiffies;
zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
cpu_notifier(sched_ilb_notifier, 0);
#endif
static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
{
- int i, idle = 1;
+ int i, idle = 1, throttled = 0;
const struct cpumask *span;
- if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)
- return 1;
-
span = sched_rt_period_mask();
for_each_cpu(i, span) {
int enqueue = 0;
if (!rt_rq_throttled(rt_rq))
enqueue = 1;
}
+ if (rt_rq->rt_throttled)
+ throttled = 1;
if (enqueue)
sched_rt_rq_enqueue(rt_rq);
raw_spin_unlock(&rq->lock);
}
+ if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF))
+ return 1;
+
return idle;
}
return 0;
if (rt_rq->rt_time > runtime) {
- rt_rq->rt_throttled = 1;
- printk_once(KERN_WARNING "sched: RT throttling activated\n");
+ struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+
+ /*
+ * Don't actually throttle groups that have no runtime assigned
+ * but accrue some time due to boosting.
+ */
+ if (likely(rt_b->rt_runtime)) {
+ static bool once = false;
+
+ rt_rq->rt_throttled = 1;
+
+ if (!once) {
+ once = true;
+ printk_sched("sched: RT throttling activated\n");
+ }
+ } else {
+ /*
+ * In case we did anyway, make it go away,
+ * replenishment is a joke, since it will replenish us
+ * with exactly 0 ns.
+ */
+ rt_rq->rt_time = 0;
+ }
+
if (rt_rq_throttled(rt_rq)) {
sched_rt_rq_dequeue(rt_rq);
return 1;
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;
- schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));
+ schedstat_set(curr->se.statistics.exec_max,
+ max(curr->se.statistics.exec_max, delta_exec));
curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
next_idx:
if (idx >= MAX_RT_PRIO)
continue;
- if (next && next->prio < idx)
+ if (next && next->prio <= idx)
continue;
list_for_each_entry(rt_se, array->queue + idx, run_list) {
struct task_struct *p;
if (--p->rt.time_slice)
return;
- p->rt.time_slice = DEF_TIMESLICE;
+ p->rt.time_slice = RR_TIMESLICE;
/*
* Requeue to the end of queue if we are not the only element
* Time slice is 0 for SCHED_FIFO tasks
*/
if (task->policy == SCHED_RR)
- return DEF_TIMESLICE;
+ return RR_TIMESLICE;
else
return 0;
}
/*
* These are the 'tuning knobs' of the scheduler:
- *
- * default timeslice is 100 msecs (used only for SCHED_RR tasks).
- * Timeslices get refilled after they expire.
*/
-#define DEF_TIMESLICE (100 * HZ / 1000)
/*
* single value that denotes runtime == period, ie unlimited time.
struct rb_root tasks_timeline;
struct rb_node *rb_leftmost;
- struct list_head tasks;
- struct list_head *balance_iterator;
-
/*
* 'curr' points to currently running entity on this cfs_rq.
* It is set to NULL otherwise (i.e when none are currently running).
#ifdef CONFIG_SMP
/*
- * the part of load.weight contributed by tasks
- */
- unsigned long task_weight;
-
- /*
* h_load = weight * f(tg)
*
* Where f(tg) is the recursive weight fraction assigned to
int cpu;
int online;
+ struct list_head cfs_tasks;
+
u64 rt_avg;
u64 age_stamp;
u64 idle_stamp;
unsigned int yld_count;
/* schedule() stats */
- unsigned int sched_switch;
unsigned int sched_count;
unsigned int sched_goidle;
/* runqueue-specific stats */
seq_printf(seq,
- "cpu%d %u %u %u %u %u %u %llu %llu %lu",
+ "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
cpu, rq->yld_count,
- rq->sched_switch, rq->sched_count, rq->sched_goidle,
+ rq->sched_count, rq->sched_goidle,
rq->ttwu_count, rq->ttwu_local,
rq->rq_cpu_time,
rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
tick_nohz_irq_exit();
#endif
rcu_irq_exit();
- preempt_enable_no_resched();
+ sched_preempt_enable_no_resched();
}
/*
while (!kthread_should_stop()) {
preempt_disable();
if (!local_softirq_pending()) {
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
+ schedule_preempt_disabled();
}
__set_current_state(TASK_RUNNING);
if (local_softirq_pending())
__do_softirq();
local_irq_enable();
- preempt_enable_no_resched();
+ sched_preempt_enable_no_resched();
cond_resched();
preempt_disable();
rcu_note_context_switch((long)__bind_cpu);
projects / linux-flexiantxendom0-3.2.10.git / commitdiff