/*- * Copyright (c) 2002-2003, Jeffrey Roberson * 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 __FBSDID("$FreeBSD: head/sys/kern/sched_ule.c 121107 2003-10-15 07:47:06Z jeff $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #endif #ifdef KTRACE #include #include #endif #include #define KTR_ULE KTR_NFS /* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */ /* XXX This is bogus compatability crap for ps */ 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 SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "SCHED"); static int sched_strict; SYSCTL_INT(_kern_sched, OID_AUTO, strict, CTLFLAG_RD, &sched_strict, 0, ""); static int slice_min = 1; SYSCTL_INT(_kern_sched, OID_AUTO, slice_min, CTLFLAG_RW, &slice_min, 0, ""); static int slice_max = 10; SYSCTL_INT(_kern_sched, OID_AUTO, slice_max, CTLFLAG_RW, &slice_max, 0, ""); int realstathz; int tickincr = 1; #ifdef SMP /* Callout to handle load balancing SMP systems. */ static struct callout kseq_lb_callout; #endif /* * These datastructures are allocated within their parent datastructure but * are scheduler specific. */ struct ke_sched { int ske_slice; struct runq *ske_runq; /* The following variables are only used for pctcpu calculation */ int ske_ltick; /* Last tick that we were running on */ int ske_ftick; /* First tick that we were running on */ int ske_ticks; /* Tick count */ /* CPU that we have affinity for. */ u_char ske_cpu; }; #define ke_slice ke_sched->ske_slice #define ke_runq ke_sched->ske_runq #define ke_ltick ke_sched->ske_ltick #define ke_ftick ke_sched->ske_ftick #define ke_ticks ke_sched->ske_ticks #define ke_cpu ke_sched->ske_cpu struct kg_sched { int skg_slptime; /* Number of ticks we vol. slept */ int skg_runtime; /* Number of ticks we were running */ }; #define kg_slptime kg_sched->skg_slptime #define kg_runtime kg_sched->skg_runtime struct td_sched { int std_slptime; }; #define td_slptime td_sched->std_slptime struct td_sched td_sched; struct ke_sched ke_sched; struct kg_sched kg_sched; struct ke_sched *kse0_sched = &ke_sched; struct kg_sched *ksegrp0_sched = &kg_sched; struct p_sched *proc0_sched = NULL; struct td_sched *thread0_sched = &td_sched; /* * The priority is primarily determined by the interactivity score. Thus, we * give lower(better) priorities to kse groups that use less CPU. The nice * value is then directly added to this to allow nice to have some effect * on latency. * * PRI_RANGE: Total priority range for timeshare threads. * PRI_NRESV: Number of nice values. * PRI_BASE: The start of the dynamic range. */ #define SCHED_PRI_RANGE (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1) #define SCHED_PRI_NRESV PRIO_TOTAL #define SCHED_PRI_NHALF (PRIO_TOTAL / 2) #define SCHED_PRI_NTHRESH (SCHED_PRI_NHALF - 1) #define SCHED_PRI_BASE (PRI_MIN_TIMESHARE) #define SCHED_PRI_INTERACT(score) \ ((score) * SCHED_PRI_RANGE / SCHED_INTERACT_MAX) /* * These determine the interactivity of a process. * * SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate * before throttling back. * SLP_RUN_THROTTLE: Divisor for reducing slp/run time at fork time. * INTERACT_MAX: Maximum interactivity value. Smaller is better. * INTERACT_THRESH: Threshhold for placement on the current runq. */ #define SCHED_SLP_RUN_MAX ((hz * 2) << 10) #define SCHED_SLP_RUN_THROTTLE (100) #define SCHED_INTERACT_MAX (100) #define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2) #define SCHED_INTERACT_THRESH (20) /* * These parameters and macros determine the size of the time slice that is * granted to each thread. * * SLICE_MIN: Minimum time slice granted, in units of ticks. * SLICE_MAX: Maximum time slice granted. * SLICE_RANGE: Range of available time slices scaled by hz. * SLICE_SCALE: The number slices granted per val in the range of [0, max]. * SLICE_NICE: Determine the amount of slice granted to a scaled nice. */ #define SCHED_SLICE_MIN (slice_min) #define SCHED_SLICE_MAX (slice_max) #define SCHED_SLICE_RANGE (SCHED_SLICE_MAX - SCHED_SLICE_MIN + 1) #define SCHED_SLICE_SCALE(val, max) (((val) * SCHED_SLICE_RANGE) / (max)) #define SCHED_SLICE_NICE(nice) \ (SCHED_SLICE_MAX - SCHED_SLICE_SCALE((nice), SCHED_PRI_NTHRESH)) /* * This macro determines whether or not the kse belongs on the current or * next run queue. * * XXX nice value should effect how interactive a kg is. */ #define SCHED_INTERACTIVE(kg) \ (sched_interact_score(kg) < SCHED_INTERACT_THRESH) #define SCHED_CURR(kg, ke) \ (ke->ke_thread->td_priority != kg->kg_user_pri || \ SCHED_INTERACTIVE(kg)) /* * 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. */ #define KSEQ_NCLASS (PRI_IDLE + 1) /* Number of run classes. */ struct kseq { struct runq ksq_idle; /* Queue of IDLE threads. */ struct runq ksq_timeshare[2]; /* Run queues for !IDLE. */ struct runq *ksq_next; /* Next timeshare queue. */ struct runq *ksq_curr; /* Current queue. */ int ksq_loads[KSEQ_NCLASS]; /* Load for each class */ int ksq_load; /* Aggregate load. */ short ksq_nice[PRIO_TOTAL + 1]; /* KSEs in each nice bin. */ short ksq_nicemin; /* Least nice. */ #ifdef SMP int ksq_cpus; /* Count of CPUs in this kseq. */ unsigned int ksq_rslices; /* Slices on run queue */ #endif }; /* * One kse queue per processor. */ #ifdef SMP struct kseq kseq_cpu[MAXCPU]; struct kseq *kseq_idmap[MAXCPU]; #define KSEQ_SELF() (kseq_idmap[PCPU_GET(cpuid)]) #define KSEQ_CPU(x) (kseq_idmap[(x)]) #else struct kseq kseq_cpu; #define KSEQ_SELF() (&kseq_cpu) #define KSEQ_CPU(x) (&kseq_cpu) #endif static void sched_slice(struct kse *ke); static void sched_priority(struct ksegrp *kg); static int sched_interact_score(struct ksegrp *kg); static void sched_interact_update(struct ksegrp *kg); void sched_pctcpu_update(struct kse *ke); int sched_pickcpu(void); /* Operations on per processor queues */ static struct kse * kseq_choose(struct kseq *kseq, int steal); static void kseq_setup(struct kseq *kseq); static void kseq_add(struct kseq *kseq, struct kse *ke); static void kseq_rem(struct kseq *kseq, struct kse *ke); static void kseq_nice_add(struct kseq *kseq, int nice); static void kseq_nice_rem(struct kseq *kseq, int nice); void kseq_print(int cpu); #ifdef SMP struct kseq * kseq_load_highest(void); void kseq_balance(void *arg); void kseq_move(struct kseq *from, int cpu); #endif void kseq_print(int cpu) { struct kseq *kseq; int i; kseq = KSEQ_CPU(cpu); printf("kseq:\n"); printf("\tload: %d\n", kseq->ksq_load); printf("\tload ITHD: %d\n", kseq->ksq_loads[PRI_ITHD]); printf("\tload REALTIME: %d\n", kseq->ksq_loads[PRI_REALTIME]); printf("\tload TIMESHARE: %d\n", kseq->ksq_loads[PRI_TIMESHARE]); printf("\tload IDLE: %d\n", kseq->ksq_loads[PRI_IDLE]); printf("\tnicemin:\t%d\n", kseq->ksq_nicemin); printf("\tnice counts:\n"); for (i = 0; i < PRIO_TOTAL + 1; i++) if (kseq->ksq_nice[i]) printf("\t\t%d = %d\n", i - SCHED_PRI_NHALF, kseq->ksq_nice[i]); } static void kseq_add(struct kseq *kseq, struct kse *ke) { mtx_assert(&sched_lock, MA_OWNED); kseq->ksq_loads[PRI_BASE(ke->ke_ksegrp->kg_pri_class)]++; kseq->ksq_load++; if (ke->ke_ksegrp->kg_pri_class == PRI_TIMESHARE) CTR6(KTR_ULE, "Add kse %p to %p (slice: %d, pri: %d, nice: %d(%d))", ke, ke->ke_runq, ke->ke_slice, ke->ke_thread->td_priority, ke->ke_ksegrp->kg_nice, kseq->ksq_nicemin); if (ke->ke_ksegrp->kg_pri_class == PRI_TIMESHARE) kseq_nice_add(kseq, ke->ke_ksegrp->kg_nice); #ifdef SMP kseq->ksq_rslices += ke->ke_slice; #endif } static void kseq_rem(struct kseq *kseq, struct kse *ke) { mtx_assert(&sched_lock, MA_OWNED); kseq->ksq_loads[PRI_BASE(ke->ke_ksegrp->kg_pri_class)]--; kseq->ksq_load--; ke->ke_runq = NULL; if (ke->ke_ksegrp->kg_pri_class == PRI_TIMESHARE) kseq_nice_rem(kseq, ke->ke_ksegrp->kg_nice); #ifdef SMP kseq->ksq_rslices -= ke->ke_slice; #endif } static void kseq_nice_add(struct kseq *kseq, int nice) { mtx_assert(&sched_lock, MA_OWNED); /* Normalize to zero. */ kseq->ksq_nice[nice + SCHED_PRI_NHALF]++; if (nice < kseq->ksq_nicemin || kseq->ksq_loads[PRI_TIMESHARE] == 1) kseq->ksq_nicemin = nice; } static void kseq_nice_rem(struct kseq *kseq, int nice) { int n; mtx_assert(&sched_lock, MA_OWNED); /* Normalize to zero. */ n = nice + SCHED_PRI_NHALF; kseq->ksq_nice[n]--; KASSERT(kseq->ksq_nice[n] >= 0, ("Negative nice count.")); /* * If this wasn't the smallest nice value or there are more in * this bucket we can just return. Otherwise we have to recalculate * the smallest nice. */ if (nice != kseq->ksq_nicemin || kseq->ksq_nice[n] != 0 || kseq->ksq_loads[PRI_TIMESHARE] == 0) return; for (; n < SCHED_PRI_NRESV + 1; n++) if (kseq->ksq_nice[n]) { kseq->ksq_nicemin = n - SCHED_PRI_NHALF; return; } } #ifdef SMP /* * kseq_balance is a simple CPU load balancing algorithm. It operates by * finding the least loaded and most loaded cpu and equalizing their load * by migrating some processes. * * Dealing only with two CPUs at a time has two advantages. Firstly, most * installations will only have 2 cpus. Secondly, load balancing too much at * once can have an unpleasant effect on the system. The scheduler rarely has * enough information to make perfect decisions. So this algorithm chooses * algorithm simplicity and more gradual effects on load in larger systems. * * It could be improved by considering the priorities and slices assigned to * each task prior to balancing them. There are many pathological cases with * any approach and so the semi random algorithm below may work as well as any. * */ void kseq_balance(void *arg) { struct kseq *kseq; int high_load; int low_load; int high_cpu; int low_cpu; int move; int diff; int i; high_cpu = 0; low_cpu = 0; high_load = 0; low_load = -1; mtx_lock_spin(&sched_lock); if (smp_started == 0) goto out; for (i = 0; i < mp_maxid; i++) { if (CPU_ABSENT(i) || (i & stopped_cpus) != 0) continue; kseq = KSEQ_CPU(i); if (kseq->ksq_load > high_load) { high_load = kseq->ksq_load; high_cpu = i; } if (low_load == -1 || kseq->ksq_load < low_load) { low_load = kseq->ksq_load; low_cpu = i; } } kseq = KSEQ_CPU(high_cpu); /* * Nothing to do. */ if (high_load < kseq->ksq_cpus + 1) goto out; high_load -= kseq->ksq_cpus; if (low_load >= high_load) goto out; diff = high_load - low_load; move = diff / 2; if (diff & 0x1) move++; for (i = 0; i < move; i++) kseq_move(kseq, low_cpu); out: mtx_unlock_spin(&sched_lock); callout_reset(&kseq_lb_callout, hz, kseq_balance, NULL); return; } struct kseq * kseq_load_highest(void) { struct kseq *kseq; int load; int cpu; int i; mtx_assert(&sched_lock, MA_OWNED); cpu = 0; load = 0; for (i = 0; i < mp_maxid; i++) { if (CPU_ABSENT(i) || (i & stopped_cpus) != 0) continue; kseq = KSEQ_CPU(i); if (kseq->ksq_load > load) { load = kseq->ksq_load; cpu = i; } } kseq = KSEQ_CPU(cpu); if (load > kseq->ksq_cpus) return (kseq); return (NULL); } void kseq_move(struct kseq *from, int cpu) { struct kse *ke; ke = kseq_choose(from, 1); runq_remove(ke->ke_runq, ke); ke->ke_state = KES_THREAD; kseq_rem(from, ke); ke->ke_cpu = cpu; sched_add(ke); } #endif /* * Pick the highest priority task we have and return it. If steal is 1 we * will return kses that have been denied slices due to their nice being too * low. In the future we should prohibit stealing interrupt threads as well. */ struct kse * kseq_choose(struct kseq *kseq, int steal) { struct kse *ke; struct runq *swap; mtx_assert(&sched_lock, MA_OWNED); swap = NULL; for (;;) { ke = runq_choose(kseq->ksq_curr); if (ke == NULL) { /* * We already swaped once and didn't get anywhere. */ if (swap) break; swap = kseq->ksq_curr; kseq->ksq_curr = kseq->ksq_next; kseq->ksq_next = swap; continue; } /* * If we encounter a slice of 0 the kse is in a * TIMESHARE kse group and its nice was too far out * of the range that receives slices. */ if (ke->ke_slice == 0 && steal == 0) { runq_remove(ke->ke_runq, ke); sched_slice(ke); ke->ke_runq = kseq->ksq_next; runq_add(ke->ke_runq, ke); continue; } return (ke); } return (runq_choose(&kseq->ksq_idle)); } static void kseq_setup(struct kseq *kseq) { runq_init(&kseq->ksq_timeshare[0]); runq_init(&kseq->ksq_timeshare[1]); runq_init(&kseq->ksq_idle); kseq->ksq_curr = &kseq->ksq_timeshare[0]; kseq->ksq_next = &kseq->ksq_timeshare[1]; kseq->ksq_loads[PRI_ITHD] = 0; kseq->ksq_loads[PRI_REALTIME] = 0; kseq->ksq_loads[PRI_TIMESHARE] = 0; kseq->ksq_loads[PRI_IDLE] = 0; kseq->ksq_load = 0; #ifdef SMP kseq->ksq_rslices = 0; #endif } static void sched_setup(void *dummy) { #ifdef SMP int i; #endif slice_min = (hz/100); /* 10ms */ slice_max = (hz/7); /* ~140ms */ #ifdef SMP /* init kseqs */ /* Create the idmap. */ #ifdef ULE_HTT_EXPERIMENTAL if (smp_topology == NULL) { #else if (1) { #endif for (i = 0; i < MAXCPU; i++) { kseq_setup(&kseq_cpu[i]); kseq_idmap[i] = &kseq_cpu[i]; kseq_cpu[i].ksq_cpus = 1; } } else { int j; for (i = 0; i < smp_topology->ct_count; i++) { struct cpu_group *cg; cg = &smp_topology->ct_group[i]; kseq_setup(&kseq_cpu[i]); for (j = 0; j < MAXCPU; j++) if ((cg->cg_mask & (1 << j)) != 0) kseq_idmap[j] = &kseq_cpu[i]; kseq_cpu[i].ksq_cpus = cg->cg_count; } } callout_init(&kseq_lb_callout, CALLOUT_MPSAFE); kseq_balance(NULL); #else kseq_setup(KSEQ_SELF()); #endif mtx_lock_spin(&sched_lock); kseq_add(KSEQ_SELF(), &kse0); mtx_unlock_spin(&sched_lock); } /* * Scale the scheduling priority according to the "interactivity" of this * process. */ static void sched_priority(struct ksegrp *kg) { int pri; if (kg->kg_pri_class != PRI_TIMESHARE) return; pri = SCHED_PRI_INTERACT(sched_interact_score(kg)); pri += SCHED_PRI_BASE; pri += kg->kg_nice; if (pri > PRI_MAX_TIMESHARE) pri = PRI_MAX_TIMESHARE; else if (pri < PRI_MIN_TIMESHARE) pri = PRI_MIN_TIMESHARE; kg->kg_user_pri = pri; return; } /* * Calculate a time slice based on the properties of the kseg and the runq * that we're on. This is only for PRI_TIMESHARE ksegrps. */ static void sched_slice(struct kse *ke) { struct kseq *kseq; struct ksegrp *kg; kg = ke->ke_ksegrp; kseq = KSEQ_CPU(ke->ke_cpu); /* * Rationale: * KSEs in interactive ksegs get the minimum slice so that we * quickly notice if it abuses its advantage. * * KSEs in non-interactive ksegs are assigned a slice that is * based on the ksegs nice value relative to the least nice kseg * on the run queue for this cpu. * * If the KSE is less nice than all others it gets the maximum * slice and other KSEs will adjust their slice relative to * this when they first expire. * * There is 20 point window that starts relative to the least * nice kse on the run queue. Slice size is determined by * the kse distance from the last nice ksegrp. * * If you are outside of the window you will get no slice and * you will be reevaluated each time you are selected on the * run queue. * */ if (!SCHED_INTERACTIVE(kg)) { int nice; nice = kg->kg_nice + (0 - kseq->ksq_nicemin); if (kseq->ksq_loads[PRI_TIMESHARE] == 0 || kg->kg_nice < kseq->ksq_nicemin) ke->ke_slice = SCHED_SLICE_MAX; else if (nice <= SCHED_PRI_NTHRESH) ke->ke_slice = SCHED_SLICE_NICE(nice); else ke->ke_slice = 0; } else ke->ke_slice = SCHED_SLICE_MIN; CTR6(KTR_ULE, "Sliced %p(%d) (nice: %d, nicemin: %d, load: %d, interactive: %d)", ke, ke->ke_slice, kg->kg_nice, kseq->ksq_nicemin, kseq->ksq_loads[PRI_TIMESHARE], SCHED_INTERACTIVE(kg)); /* * Check to see if we need to scale back the slp and run time * in the kg. This will cause us to forget old interactivity * while maintaining the current ratio. */ sched_interact_update(kg); return; } static void sched_interact_update(struct ksegrp *kg) { int ratio; if ((kg->kg_runtime + kg->kg_slptime) > SCHED_SLP_RUN_MAX) { ratio = (SCHED_SLP_RUN_MAX / (kg->kg_runtime + kg->kg_slptime)) * 4; kg->kg_runtime = (kg->kg_runtime * ratio) / 5; kg->kg_slptime = (kg->kg_slptime * ratio) / 5; } } static int sched_interact_score(struct ksegrp *kg) { int div; if (kg->kg_runtime > kg->kg_slptime) { div = max(1, kg->kg_runtime / SCHED_INTERACT_HALF); return (SCHED_INTERACT_HALF + (SCHED_INTERACT_HALF - (kg->kg_slptime / div))); } if (kg->kg_slptime > kg->kg_runtime) { div = max(1, kg->kg_slptime / SCHED_INTERACT_HALF); return (kg->kg_runtime / div); } /* * This can happen if slptime and runtime are 0. */ return (0); } /* * 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 (SCHED_SLICE_MAX); } 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; } #ifdef SMP /* XXX Should be changed to kseq_load_lowest() */ int sched_pickcpu(void) { struct kseq *kseq; int load; int cpu; int i; mtx_assert(&sched_lock, MA_OWNED); if (!smp_started) return (0); load = 0; cpu = 0; for (i = 0; i < mp_maxid; i++) { if (CPU_ABSENT(i) || (i & stopped_cpus) != 0) continue; kseq = KSEQ_CPU(i); if (kseq->ksq_load < load) { cpu = i; load = kseq->ksq_load; } } CTR1(KTR_RUNQ, "sched_pickcpu: %d", cpu); return (cpu); } #else int sched_pickcpu(void) { return (0); } #endif void sched_prio(struct thread *td, u_char prio) { mtx_assert(&sched_lock, MA_OWNED); if (TD_ON_RUNQ(td)) { adjustrunqueue(td, prio); } else { td->td_priority = prio; } } void sched_switchout(struct thread *td) { struct kse *ke; mtx_assert(&sched_lock, MA_OWNED); ke = td->td_kse; td->td_last_kse = ke; td->td_lastcpu = td->td_oncpu; td->td_oncpu = NOCPU; td->td_flags &= ~TDF_NEEDRESCHED; if (TD_IS_RUNNING(td)) { if (td->td_proc->p_flag & P_SA) { kseq_rem(KSEQ_CPU(ke->ke_cpu), ke); setrunqueue(td); } else { /* * This queue is always correct except for idle threads which * have a higher priority due to priority propagation. */ if (ke->ke_ksegrp->kg_pri_class == PRI_IDLE && ke->ke_thread->td_priority > PRI_MIN_IDLE) ke->ke_runq = KSEQ_SELF()->ksq_curr; runq_add(ke->ke_runq, ke); /* setrunqueue(td); */ } return; } if (ke->ke_runq) kseq_rem(KSEQ_CPU(ke->ke_cpu), ke); /* * We will not be on the run queue. So we must be * sleeping or similar. */ if (td->td_proc->p_flag & P_SA) kse_reassign(ke); } void sched_switchin(struct thread *td) { /* struct kse *ke = td->td_kse; */ mtx_assert(&sched_lock, MA_OWNED); td->td_oncpu = PCPU_GET(cpuid); } void sched_nice(struct ksegrp *kg, int nice) { struct kse *ke; struct thread *td; struct kseq *kseq; PROC_LOCK_ASSERT(kg->kg_proc, MA_OWNED); mtx_assert(&sched_lock, MA_OWNED); /* * We need to adjust the nice counts for running KSEs. */ if (kg->kg_pri_class == PRI_TIMESHARE) FOREACH_KSE_IN_GROUP(kg, ke) { if (ke->ke_runq == NULL) continue; kseq = KSEQ_CPU(ke->ke_cpu); kseq_nice_rem(kseq, kg->kg_nice); kseq_nice_add(kseq, nice); } kg->kg_nice = nice; sched_priority(kg); FOREACH_THREAD_IN_GROUP(kg, td) td->td_flags |= TDF_NEEDRESCHED; } void sched_sleep(struct thread *td, u_char prio) { mtx_assert(&sched_lock, MA_OWNED); td->td_slptime = ticks; td->td_priority = prio; CTR2(KTR_ULE, "sleep kse %p (tick: %d)", td->td_kse, td->td_slptime); } void sched_wakeup(struct thread *td) { mtx_assert(&sched_lock, MA_OWNED); /* * Let the kseg know how long we slept for. This is because process * interactivity behavior is modeled in the kseg. */ if (td->td_slptime) { struct ksegrp *kg; int hzticks; kg = td->td_ksegrp; hzticks = ticks - td->td_slptime; kg->kg_slptime += hzticks << 10; sched_interact_update(kg); sched_priority(kg); if (td->td_kse) sched_slice(td->td_kse); CTR2(KTR_ULE, "wakeup kse %p (%d ticks)", td->td_kse, hzticks); td->td_slptime = 0; } setrunqueue(td); if (td->td_priority < curthread->td_priority) curthread->td_flags |= TDF_NEEDRESCHED; } /* * Penalize the parent for creating a new child and initialize the child's * priority. */ void sched_fork(struct proc *p, struct proc *p1) { mtx_assert(&sched_lock, MA_OWNED); sched_fork_ksegrp(FIRST_KSEGRP_IN_PROC(p), FIRST_KSEGRP_IN_PROC(p1)); sched_fork_kse(FIRST_KSE_IN_PROC(p), FIRST_KSE_IN_PROC(p1)); sched_fork_thread(FIRST_THREAD_IN_PROC(p), FIRST_THREAD_IN_PROC(p1)); } void sched_fork_kse(struct kse *ke, struct kse *child) { child->ke_slice = 1; /* Attempt to quickly learn interactivity. */ child->ke_cpu = ke->ke_cpu; /* sched_pickcpu(); */ child->ke_runq = NULL; /* Grab our parents cpu estimation information. */ child->ke_ticks = ke->ke_ticks; child->ke_ltick = ke->ke_ltick; child->ke_ftick = ke->ke_ftick; } void sched_fork_ksegrp(struct ksegrp *kg, struct ksegrp *child) { PROC_LOCK_ASSERT(child->kg_proc, MA_OWNED); /* XXX Need something better here */ child->kg_slptime = kg->kg_slptime / SCHED_SLP_RUN_THROTTLE; child->kg_runtime = kg->kg_runtime / SCHED_SLP_RUN_THROTTLE; kg->kg_runtime += tickincr << 10; sched_interact_update(kg); child->kg_user_pri = kg->kg_user_pri; child->kg_nice = kg->kg_nice; } void sched_fork_thread(struct thread *td, struct thread *child) { } void sched_class(struct ksegrp *kg, int class) { struct kseq *kseq; struct kse *ke; mtx_assert(&sched_lock, MA_OWNED); if (kg->kg_pri_class == class) return; FOREACH_KSE_IN_GROUP(kg, ke) { if (ke->ke_state != KES_ONRUNQ && ke->ke_state != KES_THREAD) continue; kseq = KSEQ_CPU(ke->ke_cpu); kseq->ksq_loads[PRI_BASE(kg->kg_pri_class)]--; kseq->ksq_loads[PRI_BASE(class)]++; if (kg->kg_pri_class == PRI_TIMESHARE) kseq_nice_rem(kseq, kg->kg_nice); else if (class == PRI_TIMESHARE) kseq_nice_add(kseq, kg->kg_nice); } kg->kg_pri_class = class; } /* * Return some of the child's priority and interactivity to the parent. */ void sched_exit(struct proc *p, struct proc *child) { /* XXX Need something better here */ mtx_assert(&sched_lock, MA_OWNED); sched_exit_kse(FIRST_KSE_IN_PROC(p), FIRST_KSE_IN_PROC(child)); sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), FIRST_KSEGRP_IN_PROC(child)); } void sched_exit_kse(struct kse *ke, struct kse *child) { kseq_rem(KSEQ_CPU(child->ke_cpu), child); } void sched_exit_ksegrp(struct ksegrp *kg, struct ksegrp *child) { /* kg->kg_slptime += child->kg_slptime; */ kg->kg_runtime += child->kg_runtime; sched_interact_update(kg); } void sched_exit_thread(struct thread *td, struct thread *child) { } void sched_clock(struct kse *ke) { struct kseq *kseq; struct ksegrp *kg; struct thread *td; #if 0 struct kse *nke; #endif /* * sched_setup() apparently happens prior to stathz being set. We * need to resolve the timers earlier in the boot so we can avoid * calculating this here. */ if (realstathz == 0) { realstathz = stathz ? stathz : hz; tickincr = hz / realstathz; /* * XXX This does not work for values of stathz that are much * larger than hz. */ if (tickincr == 0) tickincr = 1; } td = ke->ke_thread; kg = ke->ke_ksegrp; mtx_assert(&sched_lock, MA_OWNED); KASSERT((td != NULL), ("schedclock: null thread pointer")); /* 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); if (td->td_flags & TDF_IDLETD) return; CTR4(KTR_ULE, "Tick kse %p (slice: %d, slptime: %d, runtime: %d)", ke, ke->ke_slice, kg->kg_slptime >> 10, kg->kg_runtime >> 10); /* * We only do slicing code for TIMESHARE ksegrps. */ if (kg->kg_pri_class != PRI_TIMESHARE) return; /* * Check for a higher priority task on the run queue. This can happen * on SMP if another processor woke up a process on our runq. */ kseq = KSEQ_SELF(); #if 0 if (kseq->ksq_load > 1 && (nke = kseq_choose(kseq, 0)) != NULL) { if (sched_strict && nke->ke_thread->td_priority < td->td_priority) td->td_flags |= TDF_NEEDRESCHED; else if (nke->ke_thread->td_priority < td->td_priority SCHED_PRIO_SLOP) if (nke->ke_thread->td_priority < td->td_priority) td->td_flags |= TDF_NEEDRESCHED; } #endif /* * We used a tick charge it to the ksegrp so that we can compute our * interactivity. */ kg->kg_runtime += tickincr << 10; sched_interact_update(kg); /* * We used up one time slice. */ ke->ke_slice--; #ifdef SMP kseq->ksq_rslices--; #endif if (ke->ke_slice > 0) return; /* * We're out of time, recompute priorities and requeue. */ kseq_rem(kseq, ke); sched_priority(kg); sched_slice(ke); if (SCHED_CURR(kg, ke)) ke->ke_runq = kseq->ksq_curr; else ke->ke_runq = kseq->ksq_next; kseq_add(kseq, ke); td->td_flags |= TDF_NEEDRESCHED; } int sched_runnable(void) { struct kseq *kseq; int load; load = 1; mtx_lock_spin(&sched_lock); kseq = KSEQ_SELF(); if (kseq->ksq_load) goto out; #ifdef SMP /* * For SMP we may steal other processor's KSEs. Just search until we * verify that at least on other cpu has a runnable task. */ if (smp_started) { int i; for (i = 0; i < mp_maxid; i++) { if (CPU_ABSENT(i) || (i & stopped_cpus) != 0) continue; kseq = KSEQ_CPU(i); if (kseq->ksq_load > kseq->ksq_cpus) goto out; } } #endif load = 0; out: mtx_unlock_spin(&sched_lock); return (load); } void sched_userret(struct thread *td) { struct ksegrp *kg; #if 0 struct kseq *kseq; struct kse *ke; #endif kg = td->td_ksegrp; if (td->td_priority != kg->kg_user_pri) { mtx_lock_spin(&sched_lock); td->td_priority = kg->kg_user_pri; /* * This optimization is temporarily disabled because it * breaks priority propagation. */ #if 0 kseq = KSEQ_SELF(); if (td->td_ksegrp->kg_pri_class == PRI_TIMESHARE && #ifdef SMP kseq->ksq_load > kseq->ksq_cpus && #else kseq->ksq_load > 1 && #endif (ke = kseq_choose(kseq, 0)) != NULL && ke->ke_thread->td_priority < td->td_priority) #endif curthread->td_flags |= TDF_NEEDRESCHED; mtx_unlock_spin(&sched_lock); } } struct kse * sched_choose(void) { struct kseq *kseq; struct kse *ke; mtx_assert(&sched_lock, MA_OWNED); #ifdef SMP retry: #endif kseq = KSEQ_SELF(); ke = kseq_choose(kseq, 0); if (ke) { runq_remove(ke->ke_runq, ke); ke->ke_state = KES_THREAD; if (ke->ke_ksegrp->kg_pri_class == PRI_TIMESHARE) { CTR4(KTR_ULE, "Run kse %p from %p (slice: %d, pri: %d)", ke, ke->ke_runq, ke->ke_slice, ke->ke_thread->td_priority); } return (ke); } #ifdef SMP if (smp_started) { /* * Find the cpu with the highest load and steal one proc. */ if ((kseq = kseq_load_highest()) == NULL) return (NULL); /* * Remove this kse from this kseq and runq and then requeue * on the current processor. Then we will dequeue it * normally above. */ kseq_move(kseq, PCPU_GET(cpuid)); goto retry; } #endif return (NULL); } void sched_add(struct kse *ke) { struct kseq *kseq; struct ksegrp *kg; mtx_assert(&sched_lock, MA_OWNED); KASSERT((ke->ke_thread != NULL), ("sched_add: No thread on KSE")); KASSERT((ke->ke_thread->td_kse != NULL), ("sched_add: No KSE on thread")); 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)); kg = ke->ke_ksegrp; switch (PRI_BASE(kg->kg_pri_class)) { case PRI_ITHD: case PRI_REALTIME: kseq = KSEQ_SELF(); ke->ke_runq = kseq->ksq_curr; ke->ke_slice = SCHED_SLICE_MAX; ke->ke_cpu = PCPU_GET(cpuid); break; case PRI_TIMESHARE: kseq = KSEQ_CPU(ke->ke_cpu); if (SCHED_CURR(kg, ke)) ke->ke_runq = kseq->ksq_curr; else ke->ke_runq = kseq->ksq_next; break; case PRI_IDLE: kseq = KSEQ_CPU(ke->ke_cpu); /* * This is for priority prop. */ if (ke->ke_thread->td_priority > PRI_MIN_IDLE) ke->ke_runq = kseq->ksq_curr; else ke->ke_runq = &kseq->ksq_idle; ke->ke_slice = SCHED_SLICE_MIN; break; default: panic("Unknown pri class.\n"); break; } ke->ke_ksegrp->kg_runq_kses++; ke->ke_state = KES_ONRUNQ; runq_add(ke->ke_runq, ke); kseq_add(kseq, ke); } void sched_rem(struct kse *ke) { struct kseq *kseq; mtx_assert(&sched_lock, MA_OWNED); KASSERT((ke->ke_state == KES_ONRUNQ), ("KSE not on run queue")); ke->ke_state = KES_THREAD; ke->ke_ksegrp->kg_runq_kses--; kseq = KSEQ_CPU(ke->ke_cpu); runq_remove(ke->ke_runq, ke); kseq_rem(kseq, ke); } fixpt_t sched_pctcpu(struct kse *ke) { fixpt_t pctcpu; pctcpu = 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_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); } int sched_sizeof_kse(void) { return (sizeof(struct kse) + sizeof(struct ke_sched)); } 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)); }