36ec198bd5
yield() and sched_yield() syscalls. Every scheduler has its own way to relinquish cpu, the ULE and CORE schedulers have two internal run- queues, a timesharing thread which calls yield() syscall should be moved to inactive queue.
1411 lines
36 KiB
C
1411 lines
36 KiB
C
/*-
|
|
* Copyright (c) 1982, 1986, 1990, 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
* (c) UNIX System Laboratories, Inc.
|
|
* All or some portions of this file are derived from material licensed
|
|
* to the University of California by American Telephone and Telegraph
|
|
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
|
|
* the permission of UNIX System Laboratories, Inc.
|
|
*
|
|
* 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, 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.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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"
|
|
|
|
#define kse td_sched
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/ktr.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/kthread.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/sched.h>
|
|
#include <sys/smp.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/sx.h>
|
|
#include <sys/turnstile.h>
|
|
#include <machine/smp.h>
|
|
|
|
#ifdef HWPMC_HOOKS
|
|
#include <sys/pmckern.h>
|
|
#endif
|
|
|
|
/*
|
|
* INVERSE_ESTCPU_WEIGHT is only suitable for statclock() frequencies in
|
|
* the range 100-256 Hz (approximately).
|
|
*/
|
|
#define ESTCPULIM(e) \
|
|
min((e), INVERSE_ESTCPU_WEIGHT * (NICE_WEIGHT * (PRIO_MAX - PRIO_MIN) - \
|
|
RQ_PPQ) + INVERSE_ESTCPU_WEIGHT - 1)
|
|
#ifdef SMP
|
|
#define INVERSE_ESTCPU_WEIGHT (8 * smp_cpus)
|
|
#else
|
|
#define INVERSE_ESTCPU_WEIGHT 8 /* 1 / (priorities per estcpu level). */
|
|
#endif
|
|
#define NICE_WEIGHT 1 /* Priorities per nice level. */
|
|
|
|
/*
|
|
* The schedulable entity that can be given a context to run.
|
|
* A process may have several of these. Probably one per processor
|
|
* but posibly a few more. In this universe they are grouped
|
|
* with a KSEG that contains the priority and niceness
|
|
* for the group.
|
|
*/
|
|
struct kse {
|
|
TAILQ_ENTRY(kse) ke_procq; /* (j/z) Run queue. */
|
|
struct thread *ke_thread; /* (*) Active associated thread. */
|
|
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) KSE status. */
|
|
int ke_cpticks; /* (j) Ticks of cpu time. */
|
|
struct runq *ke_runq; /* runq the kse is currently on */
|
|
};
|
|
|
|
#define ke_proc ke_thread->td_proc
|
|
#define ke_ksegrp ke_thread->td_ksegrp
|
|
|
|
#define td_kse td_sched
|
|
|
|
/* flags kept in td_flags */
|
|
#define TDF_DIDRUN TDF_SCHED0 /* KSE actually ran. */
|
|
#define TDF_EXIT TDF_SCHED1 /* KSE is being killed. */
|
|
#define TDF_BOUND TDF_SCHED2
|
|
|
|
#define ke_flags ke_thread->td_flags
|
|
#define KEF_DIDRUN TDF_DIDRUN /* KSE actually ran. */
|
|
#define KEF_EXIT TDF_EXIT /* KSE is being killed. */
|
|
#define KEF_BOUND TDF_BOUND /* stuck to one CPU */
|
|
|
|
#define SKE_RUNQ_PCPU(ke) \
|
|
((ke)->ke_runq != 0 && (ke)->ke_runq != &runq)
|
|
|
|
struct kg_sched {
|
|
struct thread *skg_last_assigned; /* (j) Last thread assigned to */
|
|
/* the system scheduler. */
|
|
int skg_avail_opennings; /* (j) Num KSEs requested in group. */
|
|
int skg_concurrency; /* (j) Num KSEs 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 SLOT_RELEASE(kg) \
|
|
do { \
|
|
kg->kg_avail_opennings++; \
|
|
CTR3(KTR_RUNQ, "kg %p(%d) Slot released (->%d)", \
|
|
kg, \
|
|
kg->kg_concurrency, \
|
|
kg->kg_avail_opennings); \
|
|
/* KASSERT((kg->kg_avail_opennings <= kg->kg_concurrency), \
|
|
("slots out of whack"));*/ \
|
|
} while (0)
|
|
|
|
#define SLOT_USE(kg) \
|
|
do { \
|
|
kg->kg_avail_opennings--; \
|
|
CTR3(KTR_RUNQ, "kg %p(%d) Slot used (->%d)", \
|
|
kg, \
|
|
kg->kg_concurrency, \
|
|
kg->kg_avail_opennings); \
|
|
/* KASSERT((kg->kg_avail_opennings >= 0), \
|
|
("slots out of whack"));*/ \
|
|
} while (0)
|
|
|
|
/*
|
|
* KSE_CAN_MIGRATE macro returns true if the kse can migrate between
|
|
* cpus.
|
|
*/
|
|
#define KSE_CAN_MIGRATE(ke) \
|
|
((ke)->ke_thread->td_pinned == 0 && ((ke)->ke_flags & KEF_BOUND) == 0)
|
|
|
|
static struct kse kse0;
|
|
static struct kg_sched kg_sched0;
|
|
|
|
static int sched_tdcnt; /* Total runnable threads in the system. */
|
|
static int sched_quantum; /* Roundrobin scheduling quantum in ticks. */
|
|
#define SCHED_QUANTUM (hz / 10) /* Default sched quantum */
|
|
|
|
static struct callout roundrobin_callout;
|
|
|
|
static void slot_fill(struct ksegrp *kg);
|
|
static struct kse *sched_choose(void); /* XXX Should be thread * */
|
|
|
|
static void setup_runqs(void);
|
|
static void roundrobin(void *arg);
|
|
static void schedcpu(void);
|
|
static void schedcpu_thread(void);
|
|
static void sched_priority(struct thread *td, u_char prio);
|
|
static void sched_setup(void *dummy);
|
|
static void maybe_resched(struct thread *td);
|
|
static void updatepri(struct ksegrp *kg);
|
|
static void resetpriority(struct ksegrp *kg);
|
|
static void resetpriority_thread(struct thread *td, struct ksegrp *kg);
|
|
#ifdef SMP
|
|
static int forward_wakeup(int cpunum);
|
|
#endif
|
|
|
|
static struct kproc_desc sched_kp = {
|
|
"schedcpu",
|
|
schedcpu_thread,
|
|
NULL
|
|
};
|
|
SYSINIT(schedcpu, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, kproc_start, &sched_kp)
|
|
SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL)
|
|
|
|
/*
|
|
* Global run queue.
|
|
*/
|
|
static struct runq runq;
|
|
|
|
#ifdef SMP
|
|
/*
|
|
* Per-CPU run queues
|
|
*/
|
|
static struct runq runq_pcpu[MAXCPU];
|
|
#endif
|
|
|
|
static void
|
|
setup_runqs(void)
|
|
{
|
|
#ifdef SMP
|
|
int i;
|
|
|
|
for (i = 0; i < MAXCPU; ++i)
|
|
runq_init(&runq_pcpu[i]);
|
|
#endif
|
|
|
|
runq_init(&runq);
|
|
}
|
|
|
|
static int
|
|
sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error, new_val;
|
|
|
|
new_val = sched_quantum * tick;
|
|
error = sysctl_handle_int(oidp, &new_val, 0, req);
|
|
if (error != 0 || req->newptr == NULL)
|
|
return (error);
|
|
if (new_val < tick)
|
|
return (EINVAL);
|
|
sched_quantum = new_val / tick;
|
|
hogticks = 2 * sched_quantum;
|
|
return (0);
|
|
}
|
|
|
|
SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RD, 0, "Scheduler");
|
|
|
|
SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "4BSD", 0,
|
|
"Scheduler name");
|
|
|
|
SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW,
|
|
0, sizeof sched_quantum, sysctl_kern_quantum, "I",
|
|
"Roundrobin scheduling quantum in microseconds");
|
|
|
|
#ifdef SMP
|
|
/* Enable forwarding of wakeups to all other cpus */
|
|
SYSCTL_NODE(_kern_sched, OID_AUTO, ipiwakeup, CTLFLAG_RD, NULL, "Kernel SMP");
|
|
|
|
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 int sched_followon = 0;
|
|
SYSCTL_INT(_kern_sched, OID_AUTO, followon, CTLFLAG_RW,
|
|
&sched_followon, 0,
|
|
"allow threads to share a quantum");
|
|
|
|
static int sched_pfollowons = 0;
|
|
SYSCTL_INT(_kern_sched, OID_AUTO, pfollowons, CTLFLAG_RD,
|
|
&sched_pfollowons, 0,
|
|
"number of followons done to a different ksegrp");
|
|
|
|
static int sched_kgfollowons = 0;
|
|
SYSCTL_INT(_kern_sched, OID_AUTO, kgfollowons, CTLFLAG_RD,
|
|
&sched_kgfollowons, 0,
|
|
"number of followons done in a ksegrp");
|
|
|
|
static __inline void
|
|
sched_load_add(void)
|
|
{
|
|
sched_tdcnt++;
|
|
CTR1(KTR_SCHED, "global load: %d", sched_tdcnt);
|
|
}
|
|
|
|
static __inline void
|
|
sched_load_rem(void)
|
|
{
|
|
sched_tdcnt--;
|
|
CTR1(KTR_SCHED, "global load: %d", sched_tdcnt);
|
|
}
|
|
/*
|
|
* Arrange to reschedule if necessary, taking the priorities and
|
|
* schedulers into account.
|
|
*/
|
|
static void
|
|
maybe_resched(struct thread *td)
|
|
{
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (td->td_priority < curthread->td_priority)
|
|
curthread->td_flags |= TDF_NEEDRESCHED;
|
|
}
|
|
|
|
/*
|
|
* Force switch among equal priority processes every 100ms.
|
|
* We don't actually need to force a context switch of the current process.
|
|
* The act of firing the event triggers a context switch to softclock() and
|
|
* then switching back out again which is equivalent to a preemption, thus
|
|
* no further work is needed on the local CPU.
|
|
*/
|
|
/* ARGSUSED */
|
|
static void
|
|
roundrobin(void *arg)
|
|
{
|
|
|
|
#ifdef SMP
|
|
mtx_lock_spin(&sched_lock);
|
|
forward_roundrobin();
|
|
mtx_unlock_spin(&sched_lock);
|
|
#endif
|
|
|
|
callout_reset(&roundrobin_callout, sched_quantum, roundrobin, NULL);
|
|
}
|
|
|
|
/*
|
|
* Constants for digital decay and forget:
|
|
* 90% of (kg_estcpu) usage in 5 * loadav time
|
|
* 95% of (ke_pctcpu) usage in 60 seconds (load insensitive)
|
|
* Note that, as ps(1) mentions, this can let percentages
|
|
* total over 100% (I've seen 137.9% for 3 processes).
|
|
*
|
|
* Note that schedclock() updates kg_estcpu and p_cpticks asynchronously.
|
|
*
|
|
* We wish to decay away 90% of kg_estcpu in (5 * loadavg) seconds.
|
|
* That is, the system wants to compute a value of decay such
|
|
* that the following for loop:
|
|
* for (i = 0; i < (5 * loadavg); i++)
|
|
* kg_estcpu *= decay;
|
|
* will compute
|
|
* kg_estcpu *= 0.1;
|
|
* for all values of loadavg:
|
|
*
|
|
* Mathematically this loop can be expressed by saying:
|
|
* decay ** (5 * loadavg) ~= .1
|
|
*
|
|
* The system computes decay as:
|
|
* decay = (2 * loadavg) / (2 * loadavg + 1)
|
|
*
|
|
* We wish to prove that the system's computation of decay
|
|
* will always fulfill the equation:
|
|
* decay ** (5 * loadavg) ~= .1
|
|
*
|
|
* If we compute b as:
|
|
* b = 2 * loadavg
|
|
* then
|
|
* decay = b / (b + 1)
|
|
*
|
|
* We now need to prove two things:
|
|
* 1) Given factor ** (5 * loadavg) ~= .1, prove factor == b/(b+1)
|
|
* 2) Given b/(b+1) ** power ~= .1, prove power == (5 * loadavg)
|
|
*
|
|
* Facts:
|
|
* For x close to zero, exp(x) =~ 1 + x, since
|
|
* exp(x) = 0! + x**1/1! + x**2/2! + ... .
|
|
* therefore exp(-1/b) =~ 1 - (1/b) = (b-1)/b.
|
|
* For x close to zero, ln(1+x) =~ x, since
|
|
* ln(1+x) = x - x**2/2 + x**3/3 - ... -1 < x < 1
|
|
* therefore ln(b/(b+1)) = ln(1 - 1/(b+1)) =~ -1/(b+1).
|
|
* ln(.1) =~ -2.30
|
|
*
|
|
* Proof of (1):
|
|
* Solve (factor)**(power) =~ .1 given power (5*loadav):
|
|
* solving for factor,
|
|
* ln(factor) =~ (-2.30/5*loadav), or
|
|
* factor =~ exp(-1/((5/2.30)*loadav)) =~ exp(-1/(2*loadav)) =
|
|
* exp(-1/b) =~ (b-1)/b =~ b/(b+1). QED
|
|
*
|
|
* Proof of (2):
|
|
* Solve (factor)**(power) =~ .1 given factor == (b/(b+1)):
|
|
* solving for power,
|
|
* power*ln(b/(b+1)) =~ -2.30, or
|
|
* power =~ 2.3 * (b + 1) = 4.6*loadav + 2.3 =~ 5*loadav. QED
|
|
*
|
|
* Actual power values for the implemented algorithm are as follows:
|
|
* loadav: 1 2 3 4
|
|
* power: 5.68 10.32 14.94 19.55
|
|
*/
|
|
|
|
/* calculations for digital decay to forget 90% of usage in 5*loadav sec */
|
|
#define loadfactor(loadav) (2 * (loadav))
|
|
#define decay_cpu(loadfac, cpu) (((loadfac) * (cpu)) / ((loadfac) + FSCALE))
|
|
|
|
/* decay 95% of `ke_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, "");
|
|
|
|
/*
|
|
* If `ccpu' is not equal to `exp(-1/20)' and you still want to use the
|
|
* faster/more-accurate formula, you'll have to estimate CCPU_SHIFT below
|
|
* and possibly adjust FSHIFT in "param.h" so that (FSHIFT >= CCPU_SHIFT).
|
|
*
|
|
* To estimate CCPU_SHIFT for exp(-1/20), the following formula was used:
|
|
* 1 - exp(-1/20) ~= 0.0487 ~= 0.0488 == 1 (fixed pt, *11* bits).
|
|
*
|
|
* If you don't want to bother with the faster/more-accurate formula, you
|
|
* can set CCPU_SHIFT to (FSHIFT + 1) which will use a slower/less-accurate
|
|
* (more general) method of calculating the %age of CPU used by a process.
|
|
*/
|
|
#define CCPU_SHIFT 11
|
|
|
|
/*
|
|
* Recompute process priorities, every hz ticks.
|
|
* MP-safe, called without the Giant mutex.
|
|
*/
|
|
/* ARGSUSED */
|
|
static void
|
|
schedcpu(void)
|
|
{
|
|
register fixpt_t loadfac = loadfactor(averunnable.ldavg[0]);
|
|
struct thread *td;
|
|
struct proc *p;
|
|
struct kse *ke;
|
|
struct ksegrp *kg;
|
|
int awake, realstathz;
|
|
|
|
realstathz = stathz ? stathz : hz;
|
|
sx_slock(&allproc_lock);
|
|
FOREACH_PROC_IN_SYSTEM(p) {
|
|
/*
|
|
* Prevent state changes and protect run queue.
|
|
*/
|
|
mtx_lock_spin(&sched_lock);
|
|
/*
|
|
* Increment time in/out of memory. We ignore overflow; with
|
|
* 16-bit int's (remember them?) overflow takes 45 days.
|
|
*/
|
|
p->p_swtime++;
|
|
FOREACH_KSEGRP_IN_PROC(p, kg) {
|
|
awake = 0;
|
|
FOREACH_THREAD_IN_GROUP(kg, td) {
|
|
ke = td->td_kse;
|
|
/*
|
|
* Increment sleep time (if sleeping). We
|
|
* ignore overflow, as above.
|
|
*/
|
|
/*
|
|
* The kse slptimes are not touched in wakeup
|
|
* because the thread may not HAVE a KSE.
|
|
*/
|
|
if (ke->ke_state == KES_ONRUNQ) {
|
|
awake = 1;
|
|
ke->ke_flags &= ~KEF_DIDRUN;
|
|
} else if ((ke->ke_state == KES_THREAD) &&
|
|
(TD_IS_RUNNING(td))) {
|
|
awake = 1;
|
|
/* Do not clear KEF_DIDRUN */
|
|
} else if (ke->ke_flags & KEF_DIDRUN) {
|
|
awake = 1;
|
|
ke->ke_flags &= ~KEF_DIDRUN;
|
|
}
|
|
|
|
/*
|
|
* ke_pctcpu is only for ps and ttyinfo().
|
|
* Do it per kse, and add them up at the end?
|
|
* XXXKSE
|
|
*/
|
|
ke->ke_pctcpu = (ke->ke_pctcpu * ccpu) >>
|
|
FSHIFT;
|
|
/*
|
|
* If the kse has been idle the entire second,
|
|
* stop recalculating its priority until
|
|
* it wakes up.
|
|
*/
|
|
if (ke->ke_cpticks == 0)
|
|
continue;
|
|
#if (FSHIFT >= CCPU_SHIFT)
|
|
ke->ke_pctcpu += (realstathz == 100)
|
|
? ((fixpt_t) ke->ke_cpticks) <<
|
|
(FSHIFT - CCPU_SHIFT) :
|
|
100 * (((fixpt_t) ke->ke_cpticks)
|
|
<< (FSHIFT - CCPU_SHIFT)) / realstathz;
|
|
#else
|
|
ke->ke_pctcpu += ((FSCALE - ccpu) *
|
|
(ke->ke_cpticks *
|
|
FSCALE / realstathz)) >> FSHIFT;
|
|
#endif
|
|
ke->ke_cpticks = 0;
|
|
} /* end of kse loop */
|
|
/*
|
|
* If there are ANY running threads in this KSEGRP,
|
|
* then don't count it as sleeping.
|
|
*/
|
|
if (awake) {
|
|
if (kg->kg_slptime > 1) {
|
|
/*
|
|
* In an ideal world, this should not
|
|
* happen, because whoever woke us
|
|
* up from the long sleep should have
|
|
* unwound the slptime and reset our
|
|
* priority before we run at the stale
|
|
* priority. Should KASSERT at some
|
|
* point when all the cases are fixed.
|
|
*/
|
|
updatepri(kg);
|
|
}
|
|
kg->kg_slptime = 0;
|
|
} else
|
|
kg->kg_slptime++;
|
|
if (kg->kg_slptime > 1)
|
|
continue;
|
|
kg->kg_estcpu = decay_cpu(loadfac, kg->kg_estcpu);
|
|
resetpriority(kg);
|
|
FOREACH_THREAD_IN_GROUP(kg, td) {
|
|
resetpriority_thread(td, kg);
|
|
}
|
|
} /* end of ksegrp loop */
|
|
mtx_unlock_spin(&sched_lock);
|
|
} /* end of process loop */
|
|
sx_sunlock(&allproc_lock);
|
|
}
|
|
|
|
/*
|
|
* Main loop for a kthread that executes schedcpu once a second.
|
|
*/
|
|
static void
|
|
schedcpu_thread(void)
|
|
{
|
|
int nowake;
|
|
|
|
for (;;) {
|
|
schedcpu();
|
|
tsleep(&nowake, 0, "-", hz);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Recalculate the priority of a process after it has slept for a while.
|
|
* For all load averages >= 1 and max kg_estcpu of 255, sleeping for at
|
|
* least six times the loadfactor will decay kg_estcpu to zero.
|
|
*/
|
|
static void
|
|
updatepri(struct ksegrp *kg)
|
|
{
|
|
register fixpt_t loadfac;
|
|
register unsigned int newcpu;
|
|
|
|
loadfac = loadfactor(averunnable.ldavg[0]);
|
|
if (kg->kg_slptime > 5 * loadfac)
|
|
kg->kg_estcpu = 0;
|
|
else {
|
|
newcpu = kg->kg_estcpu;
|
|
kg->kg_slptime--; /* was incremented in schedcpu() */
|
|
while (newcpu && --kg->kg_slptime)
|
|
newcpu = decay_cpu(loadfac, newcpu);
|
|
kg->kg_estcpu = newcpu;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Compute the priority of a process when running in user mode.
|
|
* Arrange to reschedule if the resulting priority is better
|
|
* than that of the current process.
|
|
*/
|
|
static void
|
|
resetpriority(struct ksegrp *kg)
|
|
{
|
|
register unsigned int newpriority;
|
|
|
|
if (kg->kg_pri_class == PRI_TIMESHARE) {
|
|
newpriority = PUSER + kg->kg_estcpu / INVERSE_ESTCPU_WEIGHT +
|
|
NICE_WEIGHT * (kg->kg_proc->p_nice - PRIO_MIN);
|
|
newpriority = min(max(newpriority, PRI_MIN_TIMESHARE),
|
|
PRI_MAX_TIMESHARE);
|
|
kg->kg_user_pri = newpriority;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Update the thread's priority when the associated ksegroup's user
|
|
* priority changes.
|
|
*/
|
|
static void
|
|
resetpriority_thread(struct thread *td, struct ksegrp *kg)
|
|
{
|
|
|
|
/* Only change threads with a time sharing user priority. */
|
|
if (td->td_priority < PRI_MIN_TIMESHARE ||
|
|
td->td_priority > PRI_MAX_TIMESHARE)
|
|
return;
|
|
|
|
/* XXX the whole needresched thing is broken, but not silly. */
|
|
maybe_resched(td);
|
|
|
|
sched_prio(td, kg->kg_user_pri);
|
|
}
|
|
|
|
/* ARGSUSED */
|
|
static void
|
|
sched_setup(void *dummy)
|
|
{
|
|
setup_runqs();
|
|
|
|
if (sched_quantum == 0)
|
|
sched_quantum = SCHED_QUANTUM;
|
|
hogticks = 2 * sched_quantum;
|
|
|
|
callout_init(&roundrobin_callout, CALLOUT_MPSAFE);
|
|
|
|
/* Kick off timeout driven events by calling first time. */
|
|
roundrobin(NULL);
|
|
|
|
/* Account for thread0. */
|
|
sched_load_add();
|
|
}
|
|
|
|
/* External interfaces start here */
|
|
/*
|
|
* Very early in the boot some setup of scheduler-specific
|
|
* parts of proc0 and of some 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;
|
|
kg_sched0.skg_concurrency = 1;
|
|
kg_sched0.skg_avail_opennings = 0; /* we are already running */
|
|
}
|
|
|
|
int
|
|
sched_runnable(void)
|
|
{
|
|
#ifdef SMP
|
|
return runq_check(&runq) + runq_check(&runq_pcpu[PCPU_GET(cpuid)]);
|
|
#else
|
|
return runq_check(&runq);
|
|
#endif
|
|
}
|
|
|
|
int
|
|
sched_rr_interval(void)
|
|
{
|
|
if (sched_quantum == 0)
|
|
sched_quantum = SCHED_QUANTUM;
|
|
return (sched_quantum);
|
|
}
|
|
|
|
/*
|
|
* We adjust the priority of the current process. The priority of
|
|
* a process gets worse as it accumulates CPU time. The cpu usage
|
|
* estimator (kg_estcpu) is increased here. resetpriority() will
|
|
* compute a different priority each time kg_estcpu increases by
|
|
* INVERSE_ESTCPU_WEIGHT
|
|
* (until MAXPRI is reached). The cpu usage estimator ramps up
|
|
* quite quickly when the process is running (linearly), and decays
|
|
* away exponentially, at a rate which is proportionally slower when
|
|
* the system is busy. The basic principle is that the system will
|
|
* 90% forget that the process used a lot of CPU time in 5 * loadav
|
|
* seconds. This causes the system to favor processes which haven't
|
|
* run much recently, and to round-robin among other processes.
|
|
*/
|
|
void
|
|
sched_clock(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg = td->td_ksegrp;
|
|
ke = td->td_kse;
|
|
|
|
ke->ke_cpticks++;
|
|
kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + 1);
|
|
if ((kg->kg_estcpu % INVERSE_ESTCPU_WEIGHT) == 0) {
|
|
resetpriority(kg);
|
|
resetpriority_thread(td, kg);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* charge childs scheduling cpu usage to parent.
|
|
*
|
|
* XXXKSE assume only one thread & kse & ksegrp keep estcpu in each ksegrp.
|
|
* Charge it to the ksegrp that did the wait since process estcpu is sum of
|
|
* all ksegrps, this is strictly as expected. Assume that the child process
|
|
* aggregated all the estcpu into the 'built-in' ksegrp.
|
|
*/
|
|
void
|
|
sched_exit(struct proc *p, struct thread *td)
|
|
{
|
|
sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), td);
|
|
sched_exit_thread(FIRST_THREAD_IN_PROC(p), td);
|
|
}
|
|
|
|
void
|
|
sched_exit_ksegrp(struct ksegrp *kg, struct thread *childtd)
|
|
{
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg->kg_estcpu = ESTCPULIM(kg->kg_estcpu + childtd->td_ksegrp->kg_estcpu);
|
|
}
|
|
|
|
void
|
|
sched_exit_thread(struct thread *td, struct thread *child)
|
|
{
|
|
CTR3(KTR_SCHED, "sched_exit_thread: %p(%s) prio %d",
|
|
child, child->td_proc->p_comm, child->td_priority);
|
|
if ((child->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_load_rem();
|
|
}
|
|
|
|
void
|
|
sched_fork(struct thread *td, struct thread *childtd)
|
|
{
|
|
sched_fork_ksegrp(td, childtd->td_ksegrp);
|
|
sched_fork_thread(td, childtd);
|
|
}
|
|
|
|
void
|
|
sched_fork_ksegrp(struct thread *td, struct ksegrp *child)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
child->kg_estcpu = td->td_ksegrp->kg_estcpu;
|
|
}
|
|
|
|
void
|
|
sched_fork_thread(struct thread *td, struct thread *childtd)
|
|
{
|
|
sched_newthread(childtd);
|
|
}
|
|
|
|
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) {
|
|
resetpriority(kg);
|
|
FOREACH_THREAD_IN_GROUP(kg, td) {
|
|
resetpriority_thread(td, kg);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
sched_class(struct ksegrp *kg, int class)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg->kg_pri_class = class;
|
|
}
|
|
|
|
/*
|
|
* Adjust the priority of a thread.
|
|
* This may include moving the thread within the KSEGRP,
|
|
* changing the assignment of a kse to the thread,
|
|
* and moving a KSE in the system run queue.
|
|
*/
|
|
static void
|
|
sched_priority(struct thread *td, u_char prio)
|
|
{
|
|
CTR6(KTR_SCHED, "sched_prio: %p(%s) prio %d newprio %d by %p(%s)",
|
|
td, td->td_proc->p_comm, td->td_priority, prio, curthread,
|
|
curthread->td_proc->p_comm);
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (td->td_priority == prio)
|
|
return;
|
|
if (TD_ON_RUNQ(td)) {
|
|
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_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 regulary 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_prio(td, base_pri);
|
|
} else
|
|
sched_lend_prio(td, prio);
|
|
}
|
|
|
|
void
|
|
sched_prio(struct thread *td, u_char prio)
|
|
{
|
|
u_char oldprio;
|
|
|
|
/* 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_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_sleep(struct thread *td)
|
|
{
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
td->td_ksegrp->kg_slptime = 0;
|
|
}
|
|
|
|
static void remrunqueue(struct thread *td);
|
|
|
|
void
|
|
sched_switch(struct thread *td, struct thread *newtd, int flags)
|
|
{
|
|
struct kse *ke;
|
|
struct ksegrp *kg;
|
|
struct proc *p;
|
|
|
|
ke = td->td_kse;
|
|
p = td->td_proc;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
if ((p->p_flag & P_NOLOAD) == 0)
|
|
sched_load_rem();
|
|
/*
|
|
* We are volunteering to switch out so we get to nominate
|
|
* a successor for the rest of our quantum
|
|
* First try another thread in our ksegrp, and then look for
|
|
* other ksegrps in our process.
|
|
*/
|
|
if (sched_followon &&
|
|
(p->p_flag & P_HADTHREADS) &&
|
|
(flags & SW_VOL) &&
|
|
newtd == NULL) {
|
|
/* lets schedule another thread from this process */
|
|
kg = td->td_ksegrp;
|
|
if ((newtd = TAILQ_FIRST(&kg->kg_runq))) {
|
|
remrunqueue(newtd);
|
|
sched_kgfollowons++;
|
|
} else {
|
|
FOREACH_KSEGRP_IN_PROC(p, kg) {
|
|
if ((newtd = TAILQ_FIRST(&kg->kg_runq))) {
|
|
sched_pfollowons++;
|
|
remrunqueue(newtd);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (newtd)
|
|
newtd->td_flags |= (td->td_flags & TDF_NEEDRESCHED);
|
|
|
|
td->td_lastcpu = td->td_oncpu;
|
|
td->td_flags &= ~TDF_NEEDRESCHED;
|
|
td->td_owepreempt = 0;
|
|
td->td_oncpu = NOCPU;
|
|
/*
|
|
* At the last moment, if this thread is still marked RUNNING,
|
|
* then put it back on the run queue as it has not been suspended
|
|
* or stopped or any thing else similar. We never put the idle
|
|
* threads on the run queue, however.
|
|
*/
|
|
if (td == PCPU_GET(idlethread))
|
|
TD_SET_CAN_RUN(td);
|
|
else {
|
|
SLOT_RELEASE(td->td_ksegrp);
|
|
if (TD_IS_RUNNING(td)) {
|
|
/* Put us back on the run queue (kse and all). */
|
|
setrunqueue(td, (flags & SW_PREEMPT) ?
|
|
SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
|
|
SRQ_OURSELF|SRQ_YIELDING);
|
|
} else if (p->p_flag & P_HADTHREADS) {
|
|
/*
|
|
* We will not be on the run queue. So we must be
|
|
* sleeping or similar. As it's available,
|
|
* someone else can use the KSE if they need it.
|
|
* It's NOT available if we are about to need it
|
|
*/
|
|
if (newtd == NULL || newtd->td_ksegrp != td->td_ksegrp)
|
|
slot_fill(td->td_ksegrp);
|
|
}
|
|
}
|
|
if (newtd) {
|
|
/*
|
|
* The thread we are about to run needs to be counted
|
|
* as if it had been added to the run queue and selected.
|
|
* It came from:
|
|
* * A preemption
|
|
* * An upcall
|
|
* * A followon
|
|
*/
|
|
KASSERT((newtd->td_inhibitors == 0),
|
|
("trying to run inhibitted thread"));
|
|
SLOT_USE(newtd->td_ksegrp);
|
|
newtd->td_kse->ke_flags |= KEF_DIDRUN;
|
|
TD_SET_RUNNING(newtd);
|
|
if ((newtd->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_load_add();
|
|
} else {
|
|
newtd = choosethread();
|
|
}
|
|
|
|
if (td != newtd) {
|
|
#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_wakeup(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kg = td->td_ksegrp;
|
|
if (kg->kg_slptime > 1) {
|
|
updatepri(kg);
|
|
resetpriority(kg);
|
|
}
|
|
kg->kg_slptime = 0;
|
|
setrunqueue(td, SRQ_BORING);
|
|
}
|
|
|
|
#ifdef SMP
|
|
/* enable HTT_2 if you have a 2-way HTT cpu.*/
|
|
static int
|
|
forward_wakeup(int cpunum)
|
|
{
|
|
cpumask_t map, me, 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.
|
|
*/
|
|
me = PCPU_GET(cpumask);
|
|
/*
|
|
* 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);
|
|
}
|
|
if (cpunum == NOCPU)
|
|
printf("forward_wakeup: Idle processor not found\n");
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
#ifdef SMP
|
|
static void kick_other_cpu(int pri,int cpuid);
|
|
|
|
static void
|
|
kick_other_cpu(int pri,int cpuid)
|
|
{
|
|
struct pcpu * pcpu = pcpu_find(cpuid);
|
|
int cpri = pcpu->pc_curthread->td_priority;
|
|
|
|
if (idle_cpus_mask & pcpu->pc_cpumask) {
|
|
forward_wakeups_delivered++;
|
|
ipi_selected(pcpu->pc_cpumask, IPI_AST);
|
|
return;
|
|
}
|
|
|
|
if (pri >= cpri)
|
|
return;
|
|
|
|
#if defined(IPI_PREEMPTION) && defined(PREEMPTION)
|
|
#if !defined(FULL_PREEMPTION)
|
|
if (pri <= PRI_MAX_ITHD)
|
|
#endif /* ! FULL_PREEMPTION */
|
|
{
|
|
ipi_selected(pcpu->pc_cpumask, IPI_PREEMPT);
|
|
return;
|
|
}
|
|
#endif /* defined(IPI_PREEMPTION) && defined(PREEMPTION) */
|
|
|
|
pcpu->pc_curthread->td_flags |= TDF_NEEDRESCHED;
|
|
ipi_selected( pcpu->pc_cpumask , IPI_AST);
|
|
return;
|
|
}
|
|
#endif /* SMP */
|
|
|
|
void
|
|
sched_add(struct thread *td, int flags)
|
|
#ifdef SMP
|
|
{
|
|
struct kse *ke;
|
|
int forwarded = 0;
|
|
int cpu;
|
|
int single_cpu = 0;
|
|
|
|
ke = td->td_kse;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
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"));
|
|
CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)",
|
|
td, td->td_proc->p_comm, td->td_priority, curthread,
|
|
curthread->td_proc->p_comm);
|
|
|
|
|
|
if (td->td_pinned != 0) {
|
|
cpu = td->td_lastcpu;
|
|
ke->ke_runq = &runq_pcpu[cpu];
|
|
single_cpu = 1;
|
|
CTR3(KTR_RUNQ,
|
|
"sched_add: Put kse:%p(td:%p) on cpu%d runq", ke, td, cpu);
|
|
} else if ((ke)->ke_flags & KEF_BOUND) {
|
|
/* Find CPU from bound runq */
|
|
KASSERT(SKE_RUNQ_PCPU(ke),("sched_add: bound kse not on cpu runq"));
|
|
cpu = ke->ke_runq - &runq_pcpu[0];
|
|
single_cpu = 1;
|
|
CTR3(KTR_RUNQ,
|
|
"sched_add: Put kse:%p(td:%p) on cpu%d runq", ke, td, cpu);
|
|
} else {
|
|
CTR2(KTR_RUNQ,
|
|
"sched_add: adding kse:%p (td:%p) to gbl runq", ke, td);
|
|
cpu = NOCPU;
|
|
ke->ke_runq = &runq;
|
|
}
|
|
|
|
if (single_cpu && (cpu != PCPU_GET(cpuid))) {
|
|
kick_other_cpu(td->td_priority,cpu);
|
|
} else {
|
|
|
|
if (!single_cpu) {
|
|
cpumask_t me = PCPU_GET(cpumask);
|
|
int idle = idle_cpus_mask & me;
|
|
|
|
if (!idle && ((flags & SRQ_INTR) == 0) &&
|
|
(idle_cpus_mask & ~(hlt_cpus_mask | me)))
|
|
forwarded = forward_wakeup(cpu);
|
|
}
|
|
|
|
if (!forwarded) {
|
|
if ((flags & SRQ_YIELDING) == 0 && maybe_preempt(td))
|
|
return;
|
|
else
|
|
maybe_resched(td);
|
|
}
|
|
}
|
|
|
|
if ((td->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_load_add();
|
|
SLOT_USE(td->td_ksegrp);
|
|
runq_add(ke->ke_runq, ke, flags);
|
|
ke->ke_state = KES_ONRUNQ;
|
|
}
|
|
#else /* SMP */
|
|
{
|
|
struct kse *ke;
|
|
ke = td->td_kse;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
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"));
|
|
CTR5(KTR_SCHED, "sched_add: %p(%s) prio %d by %p(%s)",
|
|
td, td->td_proc->p_comm, td->td_priority, curthread,
|
|
curthread->td_proc->p_comm);
|
|
CTR2(KTR_RUNQ, "sched_add: adding kse:%p (td:%p) to runq", ke, td);
|
|
ke->ke_runq = &runq;
|
|
|
|
/*
|
|
* If we are yielding (on the way out anyhow)
|
|
* or the thread being saved is US,
|
|
* then don't try be smart about preemption
|
|
* or kicking off another CPU
|
|
* as it won't help and may hinder.
|
|
* In the YIEDLING case, we are about to run whoever is
|
|
* being put in the queue anyhow, and in the
|
|
* OURSELF case, we are puting ourself on the run queue
|
|
* which also only happens when we are about to yield.
|
|
*/
|
|
if((flags & SRQ_YIELDING) == 0) {
|
|
if (maybe_preempt(td))
|
|
return;
|
|
}
|
|
if ((td->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_load_add();
|
|
SLOT_USE(td->td_ksegrp);
|
|
runq_add(ke->ke_runq, ke, flags);
|
|
ke->ke_state = KES_ONRUNQ;
|
|
maybe_resched(td);
|
|
}
|
|
#endif /* SMP */
|
|
|
|
void
|
|
sched_rem(struct thread *td)
|
|
{
|
|
struct kse *ke;
|
|
|
|
ke = td->td_kse;
|
|
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
|
|
("sched_rem: process swapped out"));
|
|
KASSERT((ke->ke_state == KES_ONRUNQ),
|
|
("sched_rem: KSE not on run queue"));
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
CTR5(KTR_SCHED, "sched_rem: %p(%s) prio %d by %p(%s)",
|
|
td, td->td_proc->p_comm, td->td_priority, curthread,
|
|
curthread->td_proc->p_comm);
|
|
|
|
if ((td->td_proc->p_flag & P_NOLOAD) == 0)
|
|
sched_load_rem();
|
|
SLOT_RELEASE(td->td_ksegrp);
|
|
runq_remove(ke->ke_runq, ke);
|
|
|
|
ke->ke_state = KES_THREAD;
|
|
}
|
|
|
|
/*
|
|
* Select threads to run.
|
|
* Notice that the running threads still consume a slot.
|
|
*/
|
|
struct kse *
|
|
sched_choose(void)
|
|
{
|
|
struct kse *ke;
|
|
struct runq *rq;
|
|
|
|
#ifdef SMP
|
|
struct kse *kecpu;
|
|
|
|
rq = &runq;
|
|
ke = runq_choose(&runq);
|
|
kecpu = runq_choose(&runq_pcpu[PCPU_GET(cpuid)]);
|
|
|
|
if (ke == NULL ||
|
|
(kecpu != NULL &&
|
|
kecpu->ke_thread->td_priority < ke->ke_thread->td_priority)) {
|
|
CTR2(KTR_RUNQ, "choosing kse %p from pcpu runq %d", kecpu,
|
|
PCPU_GET(cpuid));
|
|
ke = kecpu;
|
|
rq = &runq_pcpu[PCPU_GET(cpuid)];
|
|
} else {
|
|
CTR1(KTR_RUNQ, "choosing kse %p from main runq", ke);
|
|
}
|
|
|
|
#else
|
|
rq = &runq;
|
|
ke = runq_choose(&runq);
|
|
#endif
|
|
|
|
if (ke != NULL) {
|
|
runq_remove(rq, ke);
|
|
ke->ke_state = KES_THREAD;
|
|
|
|
KASSERT(ke->ke_proc->p_sflag & PS_INMEM,
|
|
("sched_choose: process swapped out"));
|
|
}
|
|
return (ke);
|
|
}
|
|
|
|
void
|
|
sched_userret(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
/*
|
|
* XXX we cheat slightly on the locking here to avoid locking in
|
|
* the usual case. Setting td_priority here is essentially an
|
|
* incomplete workaround for not setting it properly elsewhere.
|
|
* Now that some interrupt handlers are threads, not setting it
|
|
* properly elsewhere can clobber it in the window between setting
|
|
* it here and returning to user mode, so don't waste time setting
|
|
* it perfectly here.
|
|
*/
|
|
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);
|
|
}
|
|
}
|
|
|
|
void
|
|
sched_bind(struct thread *td, int cpu)
|
|
{
|
|
struct kse *ke;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
KASSERT(TD_IS_RUNNING(td),
|
|
("sched_bind: cannot bind non-running thread"));
|
|
|
|
ke = td->td_kse;
|
|
|
|
ke->ke_flags |= KEF_BOUND;
|
|
#ifdef SMP
|
|
ke->ke_runq = &runq_pcpu[cpu];
|
|
if (PCPU_GET(cpuid) == cpu)
|
|
return;
|
|
|
|
ke->ke_state = KES_THREAD;
|
|
|
|
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);
|
|
}
|
|
|
|
void
|
|
sched_relinquish(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
|
|
kg = td->td_ksegrp;
|
|
mtx_lock_spin(&sched_lock);
|
|
if (kg->kg_pri_class == PRI_TIMESHARE)
|
|
sched_prio(td, PRI_MAX_TIMESHARE);
|
|
mi_switch(SW_VOL, NULL);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
|
|
int
|
|
sched_load(void)
|
|
{
|
|
return (sched_tdcnt);
|
|
}
|
|
|
|
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 kse));
|
|
}
|
|
|
|
fixpt_t
|
|
sched_pctcpu(struct thread *td)
|
|
{
|
|
struct kse *ke;
|
|
|
|
ke = td->td_kse;
|
|
return (ke->ke_pctcpu);
|
|
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
sched_tick(void)
|
|
{
|
|
}
|
|
#define KERN_SWITCH_INCLUDE 1
|
|
#include "kern/kern_switch.c"
|