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freebsd/sys/kern/sched_core.c
David Xu 3db720fdce Add user priority loaning code to support priority propagation for 
1:1 threading's POSIX priority mutexes, the code is no-op unless
priority-aware umtx code is committed.
2006-08-25 06:12:53 +00:00

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/*-
* Copyright (c) 2005-2006, David Xu <yfxu@corp.netease.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_hwpmc_hooks.h"
#include "opt_sched.h"
#define kse td_sched
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/turnstile.h>
#include <sys/umtx.h>
#include <sys/unistd.h>
#include <sys/vmmeter.h>
#ifdef KTRACE
#include <sys/uio.h>
#include <sys/ktrace.h>
#endif
#ifdef HWPMC_HOOKS
#include <sys/pmckern.h>
#endif
#include <machine/cpu.h>
#include <machine/smp.h>
/* get process's nice value, skip value 20 which is not supported */
#define PROC_NICE(p) MIN((p)->p_nice, 19)
/* convert nice to kernel thread priority */
#define NICE_TO_PRI(nice) (PUSER + 20 + (nice))
/* get process's static priority */
#define PROC_PRI(p) NICE_TO_PRI(PROC_NICE(p))
/* convert kernel thread priority to user priority */
#define USER_PRI(pri) MIN((pri) - PUSER, 39)
/* convert nice value to user priority */
#define PROC_USER_PRI(p) (PROC_NICE(p) + 20)
/* maximum user priority, highest prio + 1 */
#define MAX_USER_PRI 40
/* maximum kernel priority its nice is 19 */
#define PUSER_MAX (PUSER + 39)
/* ticks and nanosecond converters */
#define NS_TO_HZ(n) ((n) / (1000000000 / hz))
#define HZ_TO_NS(h) ((h) * (1000000000 / hz))
/* ticks and microsecond converters */
#define MS_TO_HZ(m) ((m) / (1000000 / hz))
#define PRI_SCORE_RATIO 25
#define MAX_SCORE (MAX_USER_PRI * PRI_SCORE_RATIO / 100)
#define MAX_SLEEP_TIME (def_timeslice * MAX_SCORE)
#define NS_MAX_SLEEP_TIME (HZ_TO_NS(MAX_SLEEP_TIME))
#define STARVATION_TIME (MAX_SLEEP_TIME)
#define CURRENT_SCORE(kg) \
(MAX_SCORE * NS_TO_HZ((kg)->kg_slptime) / MAX_SLEEP_TIME)
#define SCALE_USER_PRI(x, upri) \
MAX(x * (upri + 1) / (MAX_USER_PRI/2), min_timeslice)
/*
* For a thread whose nice is zero, the score is used to determine
* if it is an interactive thread.
*/
#define INTERACTIVE_BASE_SCORE (MAX_SCORE * 20)/100
/*
* Calculate a score which a thread must have to prove itself is
* an interactive thread.
*/
#define INTERACTIVE_SCORE(ke) \
(PROC_NICE((ke)->ke_proc) * MAX_SCORE / 40 + INTERACTIVE_BASE_SCORE)
/* Test if a thread is an interactive thread */
#define THREAD_IS_INTERACTIVE(ke) \
((ke)->ke_ksegrp->kg_user_pri <= \
PROC_PRI((ke)->ke_proc) - INTERACTIVE_SCORE(ke))
/*
* Calculate how long a thread must sleep to prove itself is an
* interactive sleep.
*/
#define INTERACTIVE_SLEEP_TIME(ke) \
(HZ_TO_NS(MAX_SLEEP_TIME * \
(MAX_SCORE / 2 + INTERACTIVE_SCORE((ke)) + 1) / MAX_SCORE - 1))
#define CHILD_WEIGHT 90
#define PARENT_WEIGHT 90
#define EXIT_WEIGHT 3
#define SCHED_LOAD_SCALE 128UL
#define IDLE 0
#define IDLE_IDLE 1
#define NOT_IDLE 2
#define KQB_LEN (8) /* Number of priority status words. */
#define KQB_L2BPW (5) /* Log2(sizeof(rqb_word_t) * NBBY)). */
#define KQB_BPW (1<<KQB_L2BPW) /* Bits in an rqb_word_t. */
#define KQB_BIT(pri) (1 << ((pri) & (KQB_BPW - 1)))
#define KQB_WORD(pri) ((pri) >> KQB_L2BPW)
#define KQB_FFS(word) (ffs(word) - 1)
#define KQ_NQS 256
/*
* Type of run queue status word.
*/
typedef u_int32_t kqb_word_t;
/*
* Head of run queues.
*/
TAILQ_HEAD(krqhead, kse);
/*
* Bit array which maintains the status of a run queue. When a queue is
* non-empty the bit corresponding to the queue number will be set.
*/
struct krqbits {
kqb_word_t rqb_bits[KQB_LEN];
};
/*
* Run queue structure. Contains an array of run queues on which processes
* are placed, and a structure to maintain the status of each queue.
*/
struct krunq {
struct krqbits rq_status;
struct krqhead rq_queues[KQ_NQS];
};
/*
* The following datastructures are allocated within their parent structure
* but are scheduler specific.
*/
/*
* The schedulable entity that can be given a context to run. A process may
* have several of these.
*/
struct kse {
struct thread *ke_thread; /* (*) Active associated thread. */
TAILQ_ENTRY(kse) ke_procq; /* (j/z) Run queue. */
int ke_flags; /* (j) KEF_* flags. */
fixpt_t ke_pctcpu; /* (j) %cpu during p_swtime. */
u_char ke_rqindex; /* (j) Run queue index. */
enum {
KES_THREAD = 0x0, /* slaved to thread state */
KES_ONRUNQ
} ke_state; /* (j) thread sched specific status. */
int ke_slice; /* Time slice in ticks */
struct kseq *ke_kseq; /* Kseq the thread belongs to */
struct krunq *ke_runq; /* Assiociated runqueue */
#ifdef SMP
int ke_cpu; /* CPU that we have affinity for. */
int ke_wakeup_cpu; /* CPU that has activated us. */
#endif
int ke_activated; /* How is the thread activated. */
uint64_t ke_timestamp; /* Last timestamp dependent on state.*/
unsigned ke_lastran; /* Last timestamp the thread ran. */
/* The following variables are only used for pctcpu calculation */
int ke_ltick; /* Last tick that we were running on */
int ke_ftick; /* First tick that we were running on */
int ke_ticks; /* Tick count */
};
#define td_kse td_sched
#define ke_proc ke_thread->td_proc
#define ke_ksegrp ke_thread->td_ksegrp
/* flags kept in ke_flags */
#define KEF_BOUND 0x0001 /* Thread can not migrate. */
#define KEF_PREEMPTED 0x0002 /* Thread was preempted. */
#define KEF_MIGRATING 0x0004 /* Thread is migrating. */
#define KEF_SLEEP 0x0008 /* Thread did sleep. */
#define KEF_DIDRUN 0x0010 /* Thread actually ran. */
#define KEF_EXIT 0x0020 /* Thread is being killed. */
#define KEF_NEXTRQ 0x0400 /* Thread should be in next queue. */
#define KEF_FIRST_SLICE 0x0800 /* Thread has first time slice left. */
struct kg_sched {
struct thread *skg_last_assigned; /* (j) Last thread assigned to */
/* the system scheduler */
u_long skg_slptime; /* (j) Number of ticks we vol. slept */
u_long skg_runtime; /* (j) Temp total run time. */
int skg_avail_opennings; /* (j) Num unfilled slots in group.*/
int skg_concurrency; /* (j) Num threads requested in group.*/
};
#define kg_last_assigned kg_sched->skg_last_assigned
#define kg_avail_opennings kg_sched->skg_avail_opennings
#define kg_concurrency kg_sched->skg_concurrency
#define kg_slptime kg_sched->skg_slptime
#define kg_runtime kg_sched->skg_runtime
#define SLOT_RELEASE(kg) (kg)->kg_avail_opennings++
#define SLOT_USE(kg) (kg)->kg_avail_opennings--
/*
* Cpu percentage computation macros and defines.
*
* SCHED_CPU_TIME: Number of seconds to average the cpu usage across.
* SCHED_CPU_TICKS: Number of hz ticks to average the cpu usage across.
*/
#define SCHED_CPU_TIME 10
#define SCHED_CPU_TICKS (hz * SCHED_CPU_TIME)
/*
* kseq - per processor runqs and statistics.
*/
struct kseq {
struct krunq *ksq_curr; /* Current queue. */
struct krunq *ksq_next; /* Next timeshare queue. */
struct krunq ksq_timeshare[2]; /* Run queues for !IDLE. */
struct krunq ksq_idle; /* Queue of IDLE threads. */
int ksq_load;
uint64_t ksq_last_timestamp; /* Per-cpu last clock tick */
unsigned ksq_expired_tick; /* First expired tick */
signed char ksq_expired_nice; /* Lowest nice in nextq */
};
static struct kse kse0;
static struct kg_sched kg_sched0;
static int min_timeslice = 5;
static int def_timeslice = 100;
static int granularity = 10;
static int realstathz;
static int sched_tdcnt;
static struct kseq kseq_global;
/*
* One kse queue per processor.
*/
#ifdef SMP
static struct kseq kseq_cpu[MAXCPU];
#define KSEQ_SELF() (&kseq_cpu[PCPU_GET(cpuid)])
#define KSEQ_CPU(x) (&kseq_cpu[(x)])
#define KSEQ_ID(x) ((x) - kseq_cpu)
static cpumask_t cpu_sibling[MAXCPU];
#else /* !SMP */
#define KSEQ_SELF() (&kseq_global)
#define KSEQ_CPU(x) (&kseq_global)
#endif
/* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
static void sched_setup(void *dummy);
SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL);
static void sched_initticks(void *dummy);
SYSINIT(sched_initticks, SI_SUB_CLOCKS, SI_ORDER_THIRD, sched_initticks, NULL)
static SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler");
SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "CORE", 0,
"Scheduler name");
#ifdef SMP
/* Enable forwarding of wakeups to all other cpus */
SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup, CTLFLAG_RD, NULL, "Kernel SMP");
static int runq_fuzz = 0;
SYSCTL_INT(_kern_sched, OID_AUTO, runq_fuzz, CTLFLAG_RW, &runq_fuzz, 0, "");
static int forward_wakeup_enabled = 1;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, enabled, CTLFLAG_RW,
&forward_wakeup_enabled, 0,
"Forwarding of wakeup to idle CPUs");
static int forward_wakeups_requested = 0;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, requested, CTLFLAG_RD,
&forward_wakeups_requested, 0,
"Requests for Forwarding of wakeup to idle CPUs");
static int forward_wakeups_delivered = 0;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, delivered, CTLFLAG_RD,
&forward_wakeups_delivered, 0,
"Completed Forwarding of wakeup to idle CPUs");
static int forward_wakeup_use_mask = 1;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, usemask, CTLFLAG_RW,
&forward_wakeup_use_mask, 0,
"Use the mask of idle cpus");
static int forward_wakeup_use_loop = 0;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, useloop, CTLFLAG_RW,
&forward_wakeup_use_loop, 0,
"Use a loop to find idle cpus");
static int forward_wakeup_use_single = 0;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, onecpu, CTLFLAG_RW,
&forward_wakeup_use_single, 0,
"Only signal one idle cpu");
static int forward_wakeup_use_htt = 0;
SYSCTL_INT(_kern_sched_ipiwakeup, OID_AUTO, htt2, CTLFLAG_RW,
&forward_wakeup_use_htt, 0,
"account for htt");
#endif
static void slot_fill(struct ksegrp *);
static void krunq_add(struct krunq *, struct kse *);
static struct kse *krunq_choose(struct krunq *);
static void krunq_clrbit(struct krunq *rq, int pri);
static int krunq_findbit(struct krunq *rq);
static void krunq_init(struct krunq *);
static void krunq_remove(struct krunq *, struct kse *);
static struct kse * kseq_choose(struct kseq *);
static void kseq_load_add(struct kseq *, struct kse *);
static void kseq_load_rem(struct kseq *, struct kse *);
static void kseq_runq_add(struct kseq *, struct kse *);
static void kseq_runq_rem(struct kseq *, struct kse *);
static void kseq_setup(struct kseq *);
static int sched_is_timeshare(struct ksegrp *kg);
static struct kse *sched_choose(void);
static int sched_calc_pri(struct ksegrp *kg);
static int sched_starving(struct kseq *, unsigned, struct kse *);
static void sched_pctcpu_update(struct kse *);
static void sched_thread_priority(struct thread *, u_char);
static uint64_t sched_timestamp(void);
static int sched_recalc_pri(struct kse *ke, uint64_t now);
static int sched_timeslice(struct kse *ke);
static void sched_update_runtime(struct kse *ke, uint64_t now);
static void sched_commit_runtime(struct kse *ke);
/*
* Initialize a run structure.
*/
static void
krunq_init(struct krunq *rq)
{
int i;
bzero(rq, sizeof *rq);
for (i = 0; i < KQ_NQS; i++)
TAILQ_INIT(&rq->rq_queues[i]);
}
/*
* Clear the status bit of the queue corresponding to priority level pri,
* indicating that it is empty.
*/
static inline void
krunq_clrbit(struct krunq *rq, int pri)
{
struct krqbits *rqb;
rqb = &rq->rq_status;
rqb->rqb_bits[KQB_WORD(pri)] &= ~KQB_BIT(pri);
}
/*
* Find the index of the first non-empty run queue. This is done by
* scanning the status bits, a set bit indicates a non-empty queue.
*/
static int
krunq_findbit(struct krunq *rq)
{
struct krqbits *rqb;
int pri;
int i;
rqb = &rq->rq_status;
for (i = 0; i < KQB_LEN; i++) {
if (rqb->rqb_bits[i]) {
pri = KQB_FFS(rqb->rqb_bits[i]) + (i << KQB_L2BPW);
return (pri);
}
}
return (-1);
}
static int
krunq_check(struct krunq *rq)
{
struct krqbits *rqb;
int i;
rqb = &rq->rq_status;
for (i = 0; i < KQB_LEN; i++) {
if (rqb->rqb_bits[i])
return (1);
}
return (0);
}
/*
* Set the status bit of the queue corresponding to priority level pri,
* indicating that it is non-empty.
*/
static inline void
krunq_setbit(struct krunq *rq, int pri)
{
struct krqbits *rqb;
rqb = &rq->rq_status;
rqb->rqb_bits[KQB_WORD(pri)] |= KQB_BIT(pri);
}
/*
* Add the KSE to the queue specified by its priority, and set the
* corresponding status bit.
*/
static void
krunq_add(struct krunq *rq, struct kse *ke)
{
struct krqhead *rqh;
int pri;
pri = ke->ke_thread->td_priority;
ke->ke_rqindex = pri;
krunq_setbit(rq, pri);
rqh = &rq->rq_queues[pri];
if (ke->ke_flags & KEF_PREEMPTED)
TAILQ_INSERT_HEAD(rqh, ke, ke_procq);
else
TAILQ_INSERT_TAIL(rqh, ke, ke_procq);
}
/*
* Find the highest priority process on the run queue.
*/
static struct kse *
krunq_choose(struct krunq *rq)
{
struct krqhead *rqh;
struct kse *ke;
int pri;
mtx_assert(&sched_lock, MA_OWNED);
if ((pri = krunq_findbit(rq)) != -1) {
rqh = &rq->rq_queues[pri];
ke = TAILQ_FIRST(rqh);
KASSERT(ke != NULL, ("krunq_choose: no thread on busy queue"));
#ifdef SMP
if (pri <= PRI_MAX_ITHD || runq_fuzz <= 0)
return (ke);
/*
* In the first couple of entries, check if
* there is one for our CPU as a preference.
*/
struct kse *ke2 = ke;
const int mycpu = PCPU_GET(cpuid);
const int mymask = 1 << mycpu;
int count = runq_fuzz;
while (count-- && ke2) {
const int cpu = ke2->ke_wakeup_cpu;
if (cpu_sibling[cpu] & mymask) {
ke = ke2;
break;
}
ke2 = TAILQ_NEXT(ke2, ke_procq);
}
#endif
return (ke);
}
return (NULL);
}
/*
* Remove the KSE from the queue specified by its priority, and clear the
* corresponding status bit if the queue becomes empty.
* Caller must set ke->ke_state afterwards.
*/
static void
krunq_remove(struct krunq *rq, struct kse *ke)
{
struct krqhead *rqh;
int pri;
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
("runq_remove: process swapped out"));
pri = ke->ke_rqindex;
rqh = &rq->rq_queues[pri];
KASSERT(ke != NULL, ("krunq_remove: no proc on busy queue"));
TAILQ_REMOVE(rqh, ke, ke_procq);
if (TAILQ_EMPTY(rqh))
krunq_clrbit(rq, pri);
}
static inline void
kseq_runq_add(struct kseq *kseq, struct kse *ke)
{
krunq_add(ke->ke_runq, ke);
ke->ke_kseq = kseq;
}
static inline void
kseq_runq_rem(struct kseq *kseq, struct kse *ke)
{
krunq_remove(ke->ke_runq, ke);
ke->ke_kseq = NULL;
ke->ke_runq = NULL;
}
static inline void
kseq_load_add(struct kseq *kseq, struct kse *ke)
{
kseq->ksq_load++;
if ((ke->ke_proc->p_flag & P_NOLOAD) == 0)
sched_tdcnt++;
}
static inline void
kseq_load_rem(struct kseq *kseq, struct kse *ke)
{
kseq->ksq_load--;
if ((ke->ke_proc->p_flag & P_NOLOAD) == 0)
sched_tdcnt--;
}
/*
* Pick the highest priority task we have and return it.
*/
static struct kse *
kseq_choose(struct kseq *kseq)
{
struct krunq *swap;
struct kse *ke;
mtx_assert(&sched_lock, MA_OWNED);
ke = krunq_choose(kseq->ksq_curr);
if (ke != NULL)
return (ke);
kseq->ksq_expired_nice = PRIO_MAX + 1;
kseq->ksq_expired_tick = 0;
swap = kseq->ksq_curr;
kseq->ksq_curr = kseq->ksq_next;
kseq->ksq_next = swap;
ke = krunq_choose(kseq->ksq_curr);
if (ke != NULL)
return (ke);
return krunq_choose(&kseq->ksq_idle);
}
static inline uint64_t
sched_timestamp(void)
{
uint64_t now = cputick2usec(cpu_ticks()) * 1000;
return (now);
}
static inline int
sched_timeslice(struct kse *ke)
{
struct proc *p = ke->ke_proc;
if (ke->ke_proc->p_nice < 0)
return SCALE_USER_PRI(def_timeslice*4, PROC_USER_PRI(p));
else
return SCALE_USER_PRI(def_timeslice, PROC_USER_PRI(p));
}
static inline int
sched_is_timeshare(struct ksegrp *kg)
{
return (kg->kg_pri_class == PRI_TIMESHARE);
}
static int
sched_calc_pri(struct ksegrp *kg)
{
int score, pri;
if (sched_is_timeshare(kg)) {
score = CURRENT_SCORE(kg) - MAX_SCORE / 2;
pri = PROC_PRI(kg->kg_proc) - score;
if (pri < PUSER)
pri = PUSER;
else if (pri > PUSER_MAX)
pri = PUSER_MAX;
return (pri);
}
return (kg->kg_base_user_pri);
}
static int
sched_recalc_pri(struct kse *ke, uint64_t now)
{
uint64_t delta;
unsigned int sleep_time;
struct ksegrp *kg;
kg = ke->ke_ksegrp;
delta = now - ke->ke_timestamp;
if (__predict_false(!sched_is_timeshare(kg)))
return (kg->kg_base_user_pri);
if (delta > NS_MAX_SLEEP_TIME)
sleep_time = NS_MAX_SLEEP_TIME;
else
sleep_time = (unsigned int)delta;
if (__predict_false(sleep_time == 0))
goto out;
if (ke->ke_activated != -1 &&
sleep_time > INTERACTIVE_SLEEP_TIME(ke)) {
kg->kg_slptime = HZ_TO_NS(MAX_SLEEP_TIME - def_timeslice);
} else {
sleep_time *= (MAX_SCORE - CURRENT_SCORE(kg)) ? : 1;
/*
* If thread is waking from uninterruptible sleep, it is
* unlikely an interactive sleep, limit its sleep time to
* prevent it from being an interactive thread.
*/
if (ke->ke_activated == -1) {
if (kg->kg_slptime >= INTERACTIVE_SLEEP_TIME(ke))
sleep_time = 0;
else if (kg->kg_slptime + sleep_time >=
INTERACTIVE_SLEEP_TIME(ke)) {
kg->kg_slptime = INTERACTIVE_SLEEP_TIME(ke);
sleep_time = 0;
}
}
/*
* Thread gets priority boost here.
*/
kg->kg_slptime += sleep_time;
/* Sleep time should never be larger than maximum */
if (kg->kg_slptime > NS_MAX_SLEEP_TIME)
kg->kg_slptime = NS_MAX_SLEEP_TIME;
}
out:
return (sched_calc_pri(kg));
}
static void
sched_update_runtime(struct kse *ke, uint64_t now)
{
uint64_t runtime;
struct ksegrp *kg = ke->ke_ksegrp;
if (sched_is_timeshare(kg)) {
if ((int64_t)(now - ke->ke_timestamp) < NS_MAX_SLEEP_TIME) {
runtime = now - ke->ke_timestamp;
if ((int64_t)(now - ke->ke_timestamp) < 0)
runtime = 0;
} else {
runtime = NS_MAX_SLEEP_TIME;
}
runtime /= (CURRENT_SCORE(kg) ? : 1);
kg->kg_runtime += runtime;
ke->ke_timestamp = now;
}
}
static void
sched_commit_runtime(struct kse *ke)
{
struct ksegrp *kg = ke->ke_ksegrp;
if (kg->kg_runtime > kg->kg_slptime)
kg->kg_slptime = 0;
else
kg->kg_slptime -= kg->kg_runtime;
kg->kg_runtime = 0;
}
static void
kseq_setup(struct kseq *kseq)
{
krunq_init(&kseq->ksq_timeshare[0]);
krunq_init(&kseq->ksq_timeshare[1]);
krunq_init(&kseq->ksq_idle);
kseq->ksq_curr = &kseq->ksq_timeshare[0];
kseq->ksq_next = &kseq->ksq_timeshare[1];
kseq->ksq_expired_nice = PRIO_MAX + 1;
kseq->ksq_expired_tick = 0;
}
static void
sched_setup(void *dummy)
{
#ifdef SMP
int i;
#endif
/*
* To avoid divide-by-zero, we set realstathz a dummy value
* in case which sched_clock() called before sched_initticks().
*/
realstathz = hz;
min_timeslice = MAX(5 * hz / 1000, 1);
def_timeslice = MAX(100 * hz / 1000, 1);
granularity = MAX(10 * hz / 1000, 1);
kseq_setup(&kseq_global);
#ifdef SMP
runq_fuzz = MIN(mp_ncpus * 2, 8);
/*
* Initialize the kseqs.
*/
for (i = 0; i < MAXCPU; i++) {
struct kseq *ksq;
ksq = &kseq_cpu[i];
kseq_setup(&kseq_cpu[i]);
cpu_sibling[i] = 1 << i;
}
if (smp_topology != NULL) {
int i, j;
cpumask_t visited;
struct cpu_group *cg;
visited = 0;
for (i = 0; i < smp_topology->ct_count; i++) {
cg = &smp_topology->ct_group[i];
if (cg->cg_mask & visited)
panic("duplicated cpumask in ct_group.");
if (cg->cg_mask == 0)
continue;
visited |= cg->cg_mask;
for (j = 0; j < MAXCPU; j++) {
if ((cg->cg_mask & (1 << j)) != 0)
cpu_sibling[j] |= cg->cg_mask;
}
}
}
#endif
mtx_lock_spin(&sched_lock);
kseq_load_add(KSEQ_SELF(), &kse0);
mtx_unlock_spin(&sched_lock);
}
/* ARGSUSED */
static void
sched_initticks(void *dummy)
{
mtx_lock_spin(&sched_lock);
realstathz = stathz ? stathz : hz;
mtx_unlock_spin(&sched_lock);
}
/*
* Very early in the boot some setup of scheduler-specific
* parts of proc0 and of soem scheduler resources needs to be done.
* Called from:
* proc0_init()
*/
void
schedinit(void)
{
/*
* Set up the scheduler specific parts of proc0.
*/
proc0.p_sched = NULL; /* XXX */
ksegrp0.kg_sched = &kg_sched0;
thread0.td_sched = &kse0;
kse0.ke_thread = &thread0;
kse0.ke_state = KES_THREAD;
kse0.ke_slice = 100;
kg_sched0.skg_concurrency = 1;
kg_sched0.skg_avail_opennings = 0; /* we are already running */
}
/*
* This is only somewhat accurate since given many processes of the same
* priority they will switch when their slices run out, which will be
* at most SCHED_SLICE_MAX.
*/
int
sched_rr_interval(void)
{
return (def_timeslice);
}
static void
sched_pctcpu_update(struct kse *ke)
{
/*
* Adjust counters and watermark for pctcpu calc.
*/
if (ke->ke_ltick > ticks - SCHED_CPU_TICKS) {
/*
* Shift the tick count out so that the divide doesn't
* round away our results.
*/
ke->ke_ticks <<= 10;
ke->ke_ticks = (ke->ke_ticks / (ticks - ke->ke_ftick)) *
SCHED_CPU_TICKS;
ke->ke_ticks >>= 10;
} else
ke->ke_ticks = 0;
ke->ke_ltick = ticks;
ke->ke_ftick = ke->ke_ltick - SCHED_CPU_TICKS;
}
static void
sched_thread_priority(struct thread *td, u_char prio)
{
struct kse *ke;
ke = td->td_kse;
mtx_assert(&sched_lock, MA_OWNED);
if (__predict_false(td->td_priority == prio))
return;
if (TD_ON_RUNQ(td)) {
/*
* If the priority has been elevated due to priority
* propagation, we may have to move ourselves to a new
* queue. We still call adjustrunqueue below in case kse
* needs to fix things up.
*/
if (prio < td->td_priority && ke->ke_runq != NULL &&
ke->ke_runq != ke->ke_kseq->ksq_curr) {
krunq_remove(ke->ke_runq, ke);
ke->ke_runq = ke->ke_kseq->ksq_curr;
krunq_add(ke->ke_runq, ke);
}
adjustrunqueue(td, prio);
} else
td->td_priority = prio;
}
/*
* Update a thread's priority when it is lent another thread's
* priority.
*/
void
sched_lend_prio(struct thread *td, u_char prio)
{
td->td_flags |= TDF_BORROWING;
sched_thread_priority(td, prio);
}
/*
* Restore a thread's priority when priority propagation is
* over. The prio argument is the minimum priority the thread
* needs to have to satisfy other possible priority lending
* requests. If the thread's regular priority is less
* important than prio, the thread will keep a priority boost
* of prio.
*/
void
sched_unlend_prio(struct thread *td, u_char prio)
{
u_char base_pri;
if (td->td_base_pri >= PRI_MIN_TIMESHARE &&
td->td_base_pri <= PRI_MAX_TIMESHARE)
base_pri = td->td_ksegrp->kg_user_pri;
else
base_pri = td->td_base_pri;
if (prio >= base_pri) {
td->td_flags &= ~TDF_BORROWING;
sched_thread_priority(td, base_pri);
} else
sched_lend_prio(td, prio);
}
void
sched_prio(struct thread *td, u_char prio)
{
u_char oldprio;
if (td->td_ksegrp->kg_pri_class == PRI_TIMESHARE)
prio = MIN(prio, PUSER_MAX);
/* First, update the base priority. */
td->td_base_pri = prio;
/*
* If the thread is borrowing another thread's priority, don't
* ever lower the priority.
*/
if (td->td_flags & TDF_BORROWING && td->td_priority < prio)
return;
/* Change the real priority. */
oldprio = td->td_priority;
sched_thread_priority(td, prio);
/*
* If the thread is on a turnstile, then let the turnstile update
* its state.
*/
if (TD_ON_LOCK(td) && oldprio != prio)
turnstile_adjust(td, oldprio);
}
void
sched_user_prio(struct ksegrp *kg, u_char prio)
{
struct thread *td;
u_char oldprio;
kg->kg_base_user_pri = prio;
/* XXXKSE only for 1:1 */
td = TAILQ_FIRST(&kg->kg_threads);
if (td == NULL) {
kg->kg_user_pri = prio;
return;
}
if (td->td_flags & TDF_UBORROWING && kg->kg_user_pri <= prio)
return;
oldprio = kg->kg_user_pri;
kg->kg_user_pri = prio;
if (TD_ON_UPILOCK(td) && oldprio != prio)
umtx_pi_adjust(td, oldprio);
}
void
sched_lend_user_prio(struct thread *td, u_char prio)
{
u_char oldprio;
td->td_flags |= TDF_UBORROWING;
oldprio = td->td_ksegrp->kg_user_pri;
td->td_ksegrp->kg_user_pri = prio;
if (TD_ON_UPILOCK(td) && oldprio != prio)
umtx_pi_adjust(td, oldprio);
}
void
sched_unlend_user_prio(struct thread *td, u_char prio)
{
struct ksegrp *kg = td->td_ksegrp;
u_char base_pri;
base_pri = kg->kg_base_user_pri;
if (prio >= base_pri) {
td->td_flags &= ~TDF_UBORROWING;
sched_user_prio(kg, base_pri);
} else
sched_lend_user_prio(td, prio);
}
void
sched_switch(struct thread *td, struct thread *newtd, int flags)
{
struct kseq *ksq;
struct kse *ke;
struct ksegrp *kg;
uint64_t now;
mtx_assert(&sched_lock, MA_OWNED);
now = sched_timestamp();
ke = td->td_kse;
kg = td->td_ksegrp;
ksq = KSEQ_SELF();
td->td_lastcpu = td->td_oncpu;
td->td_oncpu = NOCPU;
td->td_flags &= ~TDF_NEEDRESCHED;
td->td_owepreempt = 0;
if (td == PCPU_GET(idlethread)) {
TD_SET_CAN_RUN(td);
} else {
sched_update_runtime(ke, now);
/* We are ending our run so make our slot available again */
SLOT_RELEASE(td->td_ksegrp);
kseq_load_rem(ksq, ke);
if (TD_IS_RUNNING(td)) {
setrunqueue(td, (flags & SW_PREEMPT) ?
SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
SRQ_OURSELF|SRQ_YIELDING);
} else {
if ((td->td_proc->p_flag & P_HADTHREADS) &&
(newtd == NULL ||
newtd->td_ksegrp != td->td_ksegrp)) {
/*
* We will not be on the run queue.
* So we must be sleeping or similar.
* Don't use the slot if we will need it
* for newtd.
*/
slot_fill(td->td_ksegrp);
}
ke->ke_flags &= ~KEF_NEXTRQ;
}
}
if (newtd != NULL) {
/*
* If we bring in a thread account for it as if it had been
* added to the run queue and then chosen.
*/
SLOT_USE(newtd->td_ksegrp);
newtd->td_kse->ke_flags |= KEF_DIDRUN;
newtd->td_kse->ke_timestamp = now;
TD_SET_RUNNING(newtd);
kseq_load_add(ksq, newtd->td_kse);
} else {
newtd = choosethread();
/* sched_choose sets ke_timestamp, just reuse it */
}
if (td != newtd) {
ke->ke_lastran = tick;
#ifdef HWPMC_HOOKS
if (PMC_PROC_IS_USING_PMCS(td->td_proc))
PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
#endif
cpu_switch(td, newtd);
#ifdef HWPMC_HOOKS
if (PMC_PROC_IS_USING_PMCS(td->td_proc))
PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN);
#endif
}
sched_lock.mtx_lock = (uintptr_t)td;
td->td_oncpu = PCPU_GET(cpuid);
}
void
sched_nice(struct proc *p, int nice)
{
struct ksegrp *kg;
struct thread *td;
PROC_LOCK_ASSERT(p, MA_OWNED);
mtx_assert(&sched_lock, MA_OWNED);
p->p_nice = nice;
FOREACH_KSEGRP_IN_PROC(p, kg) {
if (kg->kg_pri_class == PRI_TIMESHARE) {
sched_user_prio(kg, sched_calc_pri(kg));
FOREACH_THREAD_IN_GROUP(kg, td)
td->td_flags |= TDF_NEEDRESCHED;
}
}
}
void
sched_sleep(struct thread *td)
{
struct kse *ke;
mtx_assert(&sched_lock, MA_OWNED);
ke = td->td_kse;
if (td->td_flags & TDF_SINTR)
ke->ke_activated = 0;
else
ke->ke_activated = -1;
ke->ke_flags |= KEF_SLEEP;
}
void
sched_wakeup(struct thread *td)
{
struct kse *ke;
struct ksegrp *kg;
struct kseq *kseq, *mykseq;
uint64_t now;
mtx_assert(&sched_lock, MA_OWNED);
ke = td->td_kse;
kg = td->td_ksegrp;
mykseq = KSEQ_SELF();
if (ke->ke_flags & KEF_SLEEP) {
ke->ke_flags &= ~KEF_SLEEP;
if (sched_is_timeshare(kg)) {
sched_commit_runtime(ke);
now = sched_timestamp();
kseq = KSEQ_CPU(td->td_lastcpu);
#ifdef SMP
if (kseq != mykseq)
now = now - mykseq->ksq_last_timestamp +
kseq->ksq_last_timestamp;
#endif
sched_user_prio(kg, sched_recalc_pri(ke, now));
}
}
setrunqueue(td, SRQ_BORING);
}
/*
* Penalize the parent for creating a new child and initialize the child's
* priority.
*/
void
sched_fork(struct thread *td, struct thread *childtd)
{
mtx_assert(&sched_lock, MA_OWNED);
sched_fork_ksegrp(td, childtd->td_ksegrp);
sched_fork_thread(td, childtd);
}
void
sched_fork_ksegrp(struct thread *td, struct ksegrp *child)
{
struct ksegrp *kg = td->td_ksegrp;
mtx_assert(&sched_lock, MA_OWNED);
child->kg_slptime = kg->kg_slptime * CHILD_WEIGHT / 100;
if (child->kg_pri_class == PRI_TIMESHARE)
sched_user_prio(child, sched_calc_pri(child));
kg->kg_slptime = kg->kg_slptime * PARENT_WEIGHT / 100;
}
void
sched_fork_thread(struct thread *td, struct thread *child)
{
struct kse *ke;
struct kse *ke2;
sched_newthread(child);
ke = td->td_kse;
ke2 = child->td_kse;
ke2->ke_slice = (ke->ke_slice + 1) >> 1;
ke2->ke_flags |= KEF_FIRST_SLICE | (ke->ke_flags & KEF_NEXTRQ);
ke2->ke_activated = 0;
ke->ke_slice >>= 1;
if (ke->ke_slice == 0) {
ke->ke_slice = 1;
sched_tick();
}
/* Grab our parents cpu estimation information. */
ke2->ke_ticks = ke->ke_ticks;
ke2->ke_ltick = ke->ke_ltick;
ke2->ke_ftick = ke->ke_ftick;
}
void
sched_class(struct ksegrp *kg, int class)
{
mtx_assert(&sched_lock, MA_OWNED);
kg->kg_pri_class = class;
}
/*
* Return some of the child's priority and interactivity to the parent.
*/
void
sched_exit(struct proc *p, struct thread *childtd)
{
mtx_assert(&sched_lock, MA_OWNED);
sched_exit_thread(FIRST_THREAD_IN_PROC(p), childtd);
sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), childtd);
}
void
sched_exit_ksegrp(struct ksegrp *parentkg, struct thread *td)
{
if (td->td_ksegrp->kg_slptime < parentkg->kg_slptime) {
parentkg->kg_slptime = parentkg->kg_slptime /
(EXIT_WEIGHT) * (EXIT_WEIGHT - 1) +
td->td_ksegrp->kg_slptime / EXIT_WEIGHT;
}
}
void
sched_exit_thread(struct thread *td, struct thread *childtd)
{
struct kse *childke = childtd->td_kse;
struct kse *parentke = td->td_kse;
kseq_load_rem(KSEQ_SELF(), childke);
sched_update_runtime(childke, sched_timestamp());
sched_commit_runtime(childke);
if ((childke->ke_flags & KEF_FIRST_SLICE) &&
td->td_proc == childtd->td_proc->p_pptr) {
parentke->ke_slice += childke->ke_slice;
if (parentke->ke_slice > sched_timeslice(parentke))
parentke->ke_slice = sched_timeslice(parentke);
}
}
static int
sched_starving(struct kseq *ksq, unsigned now, struct kse *ke)
{
uint64_t delta;
if (ke->ke_proc->p_nice > ksq->ksq_expired_nice)
return (1);
if (ksq->ksq_expired_tick == 0)
return (0);
delta = HZ_TO_NS((uint64_t)now - ksq->ksq_expired_tick);
if (delta > STARVATION_TIME * ksq->ksq_load)
return (1);
return (0);
}
/*
* An interactive thread has smaller time slice granularity,
* a cpu hog can have larger granularity.
*/
static inline int
sched_timeslice_split(struct kse *ke)
{
int score, g;
score = (int)(MAX_SCORE - CURRENT_SCORE(ke->ke_ksegrp));
if (score == 0)
score = 1;
#ifdef SMP
g = granularity * ((1 << score) - 1) * smp_cpus;
#else
g = granularity * ((1 << score) - 1);
#endif
return (ke->ke_slice >= g && ke->ke_slice % g == 0);
}
void
sched_tick(void)
{
struct thread *td;
struct proc *p;
struct kse *ke;
struct ksegrp *kg;
struct kseq *kseq;
uint64_t now;
int cpuid;
int class;
mtx_assert(&sched_lock, MA_OWNED);
td = curthread;
ke = td->td_kse;
kg = td->td_ksegrp;
p = td->td_proc;
class = PRI_BASE(kg->kg_pri_class);
now = sched_timestamp();
cpuid = PCPU_GET(cpuid);
kseq = KSEQ_CPU(cpuid);
kseq->ksq_last_timestamp = now;
if (class == PRI_IDLE) {
/*
* Processes of equal idle priority are run round-robin.
*/
if (td != PCPU_GET(idlethread) && --ke->ke_slice <= 0) {
ke->ke_slice = def_timeslice;
td->td_flags |= TDF_NEEDRESCHED;
}
return;
}
if (class == PRI_REALTIME) {
/*
* Realtime scheduling, do round robin for RR class, FIFO
* is not affected.
*/
if (PRI_NEED_RR(kg->kg_pri_class) && --ke->ke_slice <= 0) {
ke->ke_slice = def_timeslice;
td->td_flags |= TDF_NEEDRESCHED;
}
return;
}
/*
* We skip kernel thread, though it may be classified as TIMESHARE.
*/
if (class != PRI_TIMESHARE || (p->p_flag & P_KTHREAD) != 0)
return;
if (--ke->ke_slice <= 0) {
td->td_flags |= TDF_NEEDRESCHED;
sched_update_runtime(ke, now);
sched_commit_runtime(ke);
sched_user_prio(kg, sched_calc_pri(kg));
ke->ke_slice = sched_timeslice(ke);
ke->ke_flags &= ~KEF_FIRST_SLICE;
if (ke->ke_flags & KEF_BOUND || td->td_pinned) {
if (kseq->ksq_expired_tick == 0)
kseq->ksq_expired_tick = tick;
} else {
if (kseq_global.ksq_expired_tick == 0)
kseq_global.ksq_expired_tick = tick;
}
if (!THREAD_IS_INTERACTIVE(ke) ||
sched_starving(kseq, tick, ke) ||
sched_starving(&kseq_global, tick, ke)) {
/* The thead becomes cpu hog, schedule it off. */
ke->ke_flags |= KEF_NEXTRQ;
if (ke->ke_flags & KEF_BOUND || td->td_pinned) {
if (p->p_nice < kseq->ksq_expired_nice)
kseq->ksq_expired_nice = p->p_nice;
} else {
if (p->p_nice < kseq_global.ksq_expired_nice)
kseq_global.ksq_expired_nice =
p->p_nice;
}
}
} else {
/*
* Don't allow an interactive thread which has long timeslice
* to monopolize CPU, split the long timeslice into small
* chunks. This essentially does round-robin between
* interactive threads.
*/
if (THREAD_IS_INTERACTIVE(ke) && sched_timeslice_split(ke))
td->td_flags |= TDF_NEEDRESCHED;
}
}
void
sched_clock(struct thread *td)
{
struct ksegrp *kg;
struct kse *ke;
mtx_assert(&sched_lock, MA_OWNED);
ke = td->td_kse;
kg = ke->ke_ksegrp;
/* Adjust ticks for pctcpu */
ke->ke_ticks++;
ke->ke_ltick = ticks;
/* Go up to one second beyond our max and then trim back down */
if (ke->ke_ftick + SCHED_CPU_TICKS + hz < ke->ke_ltick)
sched_pctcpu_update(ke);
}
static int
kseq_runnable(struct kseq *kseq)
{
return (krunq_check(kseq->ksq_curr) ||
krunq_check(kseq->ksq_next) ||
krunq_check(&kseq->ksq_idle));
}
int
sched_runnable(void)
{
#ifdef SMP
return (kseq_runnable(&kseq_global) || kseq_runnable(KSEQ_SELF()));
#else
return (kseq_runnable(&kseq_global));
#endif
}
void
sched_userret(struct thread *td)
{
struct ksegrp *kg;
KASSERT((td->td_flags & TDF_BORROWING) == 0,
("thread with borrowed priority returning to userland"));
kg = td->td_ksegrp;
if (td->td_priority != kg->kg_user_pri) {
mtx_lock_spin(&sched_lock);
td->td_priority = kg->kg_user_pri;
td->td_base_pri = kg->kg_user_pri;
mtx_unlock_spin(&sched_lock);
}
}
struct kse *
sched_choose(void)
{
struct kse *ke;
struct kseq *kseq;
#ifdef SMP
struct kse *kecpu;
mtx_assert(&sched_lock, MA_OWNED);
kseq = &kseq_global;
ke = kseq_choose(&kseq_global);
kecpu = kseq_choose(KSEQ_SELF());
if (ke == NULL ||
(kecpu != NULL &&
kecpu->ke_thread->td_priority < ke->ke_thread->td_priority)) {
ke = kecpu;
kseq = KSEQ_SELF();
}
#else
kseq = &kseq_global;
ke = kseq_choose(kseq);
#endif
if (ke != NULL) {
kseq_runq_rem(kseq, ke);
ke->ke_state = KES_THREAD;
ke->ke_flags &= ~KEF_PREEMPTED;
ke->ke_timestamp = sched_timestamp();
}
return (ke);
}
#ifdef SMP
static int
forward_wakeup(int cpunum, cpumask_t me)
{
cpumask_t map, dontuse;
cpumask_t map2;
struct pcpu *pc;
cpumask_t id, map3;
mtx_assert(&sched_lock, MA_OWNED);
CTR0(KTR_RUNQ, "forward_wakeup()");
if ((!forward_wakeup_enabled) ||
(forward_wakeup_use_mask == 0 && forward_wakeup_use_loop == 0))
return (0);
if (!smp_started || cold || panicstr)
return (0);
forward_wakeups_requested++;
/*
* check the idle mask we received against what we calculated before
* in the old version.
*/
/*
* don't bother if we should be doing it ourself..
*/
if ((me & idle_cpus_mask) && (cpunum == NOCPU || me == (1 << cpunum)))
return (0);
dontuse = me | stopped_cpus | hlt_cpus_mask;
map3 = 0;
if (forward_wakeup_use_loop) {
SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
id = pc->pc_cpumask;
if ( (id & dontuse) == 0 &&
pc->pc_curthread == pc->pc_idlethread) {
map3 |= id;
}
}
}
if (forward_wakeup_use_mask) {
map = 0;
map = idle_cpus_mask & ~dontuse;
/* If they are both on, compare and use loop if different */
if (forward_wakeup_use_loop) {
if (map != map3) {
printf("map (%02X) != map3 (%02X)\n",
map, map3);
map = map3;
}
}
} else {
map = map3;
}
/* If we only allow a specific CPU, then mask off all the others */
if (cpunum != NOCPU) {
KASSERT((cpunum <= mp_maxcpus),("forward_wakeup: bad cpunum."));
map &= (1 << cpunum);
} else {
/* Try choose an idle die. */
if (forward_wakeup_use_htt) {
map2 = (map & (map >> 1)) & 0x5555;
if (map2) {
map = map2;
}
}
/* set only one bit */
if (forward_wakeup_use_single) {
map = map & ((~map) + 1);
}
}
if (map) {
forward_wakeups_delivered++;
ipi_selected(map, IPI_AST);
return (1);
}
return (0);
}
#endif
void
sched_add(struct thread *td, int flags)
{
struct kseq *ksq;
struct ksegrp *kg;
struct kse *ke;
struct thread *mytd;
int class;
int nextrq;
int need_resched = 0;
#ifdef SMP
int cpu;
int mycpu;
int pinned;
struct kseq *myksq;
#endif
mtx_assert(&sched_lock, MA_OWNED);
mytd = curthread;
ke = td->td_kse;
kg = td->td_ksegrp;
KASSERT(ke->ke_state != KES_ONRUNQ,
("sched_add: kse %p (%s) already in run queue", ke,
ke->ke_proc->p_comm));
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
("sched_add: process swapped out"));
KASSERT(ke->ke_runq == NULL,
("sched_add: KSE %p is still assigned to a run queue", ke));
class = PRI_BASE(kg->kg_pri_class);
#ifdef SMP
mycpu = PCPU_GET(cpuid);
myksq = KSEQ_CPU(mycpu);
ke->ke_wakeup_cpu = mycpu;
#endif
nextrq = (ke->ke_flags & KEF_NEXTRQ);
ke->ke_flags &= ~KEF_NEXTRQ;
if (flags & SRQ_PREEMPTED)
ke->ke_flags |= KEF_PREEMPTED;
ksq = &kseq_global;
#ifdef SMP
if (td->td_pinned != 0) {
cpu = td->td_lastcpu;
ksq = KSEQ_CPU(cpu);
pinned = 1;
} else if ((ke)->ke_flags & KEF_BOUND) {
cpu = ke->ke_cpu;
ksq = KSEQ_CPU(cpu);
pinned = 1;
} else {
pinned = 0;
cpu = NOCPU;
}
#endif
switch (class) {
case PRI_ITHD:
case PRI_REALTIME:
ke->ke_runq = ksq->ksq_curr;
break;
case PRI_TIMESHARE:
if ((td->td_flags & TDF_BORROWING) == 0 && nextrq)
ke->ke_runq = ksq->ksq_next;
else
ke->ke_runq = ksq->ksq_curr;
break;
case PRI_IDLE:
/*
* This is for priority prop.
*/
if (td->td_priority < PRI_MIN_IDLE)
ke->ke_runq = ksq->ksq_curr;
else
ke->ke_runq = &ksq->ksq_idle;
break;
default:
panic("Unknown pri class.");
break;
}
#ifdef SMP
if ((ke->ke_runq == kseq_global.ksq_curr ||
ke->ke_runq == myksq->ksq_curr) &&
td->td_priority < mytd->td_priority) {
#else
if (ke->ke_runq == kseq_global.ksq_curr &&
td->td_priority < mytd->td_priority) {
#endif
struct krunq *rq;
rq = ke->ke_runq;
ke->ke_runq = NULL;
if ((flags & SRQ_YIELDING) == 0 && maybe_preempt(td))
return;
ke->ke_runq = rq;
need_resched = TDF_NEEDRESCHED;
}
SLOT_USE(kg);
ke->ke_state = KES_ONRUNQ;
kseq_runq_add(ksq, ke);
kseq_load_add(ksq, ke);
#ifdef SMP
if (pinned) {
if (cpu != mycpu) {
struct thread *running = pcpu_find(cpu)->pc_curthread;
if (ksq->ksq_curr == ke->ke_runq &&
running->td_priority < td->td_priority) {
if (td->td_priority <= PRI_MAX_ITHD)
ipi_selected(1 << cpu, IPI_PREEMPT);
else {
running->td_flags |= TDF_NEEDRESCHED;
ipi_selected(1 << cpu, IPI_AST);
}
}
} else
curthread->td_flags |= need_resched;
} else {
cpumask_t me = 1 << mycpu;
cpumask_t idle = idle_cpus_mask & me;
int forwarded = 0;
if (!idle && ((flags & SRQ_INTR) == 0) &&
(idle_cpus_mask & ~(hlt_cpus_mask | me)))
forwarded = forward_wakeup(cpu, me);
if (forwarded == 0)
curthread->td_flags |= need_resched;
}
#else
mytd->td_flags |= need_resched;
#endif
}
void
sched_rem(struct thread *td)
{
struct kseq *kseq;
struct kse *ke;
mtx_assert(&sched_lock, MA_OWNED);
ke = td->td_kse;
KASSERT((ke->ke_state == KES_ONRUNQ),
("sched_rem: KSE not on run queue"));
kseq = ke->ke_kseq;
SLOT_RELEASE(td->td_ksegrp);
kseq_runq_rem(kseq, ke);
kseq_load_rem(kseq, ke);
ke->ke_state = KES_THREAD;
}
fixpt_t
sched_pctcpu(struct thread *td)
{
fixpt_t pctcpu;
struct kse *ke;
pctcpu = 0;
ke = td->td_kse;
if (ke == NULL)
return (0);
mtx_lock_spin(&sched_lock);
if (ke->ke_ticks) {
int rtick;
/*
* Don't update more frequently than twice a second. Allowing
* this causes the cpu usage to decay away too quickly due to
* rounding errors.
*/
if (ke->ke_ftick + SCHED_CPU_TICKS < ke->ke_ltick ||
ke->ke_ltick < (ticks - (hz / 2)))
sched_pctcpu_update(ke);
/* How many rtick per second ? */
rtick = MIN(ke->ke_ticks / SCHED_CPU_TIME, SCHED_CPU_TICKS);
pctcpu = (FSCALE * ((FSCALE * rtick)/realstathz)) >> FSHIFT;
}
ke->ke_proc->p_swtime = ke->ke_ltick - ke->ke_ftick;
mtx_unlock_spin(&sched_lock);
return (pctcpu);
}
void
sched_bind(struct thread *td, int cpu)
{
struct kse *ke;
mtx_assert(&sched_lock, MA_OWNED);
ke = td->td_kse;
ke->ke_flags |= KEF_BOUND;
#ifdef SMP
ke->ke_cpu = cpu;
if (PCPU_GET(cpuid) == cpu)
return;
mi_switch(SW_VOL, NULL);
#endif
}
void
sched_unbind(struct thread *td)
{
mtx_assert(&sched_lock, MA_OWNED);
td->td_kse->ke_flags &= ~KEF_BOUND;
}
int
sched_is_bound(struct thread *td)
{
mtx_assert(&sched_lock, MA_OWNED);
return (td->td_kse->ke_flags & KEF_BOUND);
}
int
sched_load(void)
{
return (sched_tdcnt);
}
void
sched_relinquish(struct thread *td)
{
struct ksegrp *kg;
kg = td->td_ksegrp;
mtx_lock_spin(&sched_lock);
if (sched_is_timeshare(kg)) {
sched_prio(td, PRI_MAX_TIMESHARE);
td->td_kse->ke_flags |= KEF_NEXTRQ;
}
mi_switch(SW_VOL, NULL);
mtx_unlock_spin(&sched_lock);
}
int
sched_sizeof_ksegrp(void)
{
return (sizeof(struct ksegrp) + sizeof(struct kg_sched));
}
int
sched_sizeof_proc(void)
{
return (sizeof(struct proc));
}
int
sched_sizeof_thread(void)
{
return (sizeof(struct thread) + sizeof(struct td_sched));
}
#define KERN_SWITCH_INCLUDE 1
#include "kern/kern_switch.c"
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