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-rw-r--r--sys/kern/sched_ule.c2903
1 files changed, 2903 insertions, 0 deletions
diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c
new file mode 100644
index 0000000..107a15d
--- /dev/null
+++ b/sys/kern/sched_ule.c
@@ -0,0 +1,2903 @@
+/*-
+ * Copyright (c) 2002-2007, Jeffrey Roberson <jeff@freebsd.org>
+ * 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.
+ */
+
+/*
+ * This file implements the ULE scheduler. ULE supports independent CPU
+ * run queues and fine grain locking. It has superior interactive
+ * performance under load even on uni-processor systems.
+ *
+ * etymology:
+ * ULE is the last three letters in schedule. It owes its name to a
+ * generic user created for a scheduling system by Paul Mikesell at
+ * Isilon Systems and a general lack of creativity on the part of the author.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_hwpmc_hooks.h"
+#include "opt_kdtrace.h"
+#include "opt_sched.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kdb.h>
+#include <sys/kernel.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/sdt.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/vmmeter.h>
+#include <sys/cpuset.h>
+#include <sys/sbuf.h>
+
+#ifdef HWPMC_HOOKS
+#include <sys/pmckern.h>
+#endif
+
+#ifdef KDTRACE_HOOKS
+#include <sys/dtrace_bsd.h>
+int dtrace_vtime_active;
+dtrace_vtime_switch_func_t dtrace_vtime_switch_func;
+#endif
+
+#include <machine/cpu.h>
+#include <machine/smp.h>
+
+#if defined(__powerpc__) && defined(BOOKE_E500)
+#error "This architecture is not currently compatible with ULE"
+#endif
+
+#define KTR_ULE 0
+
+#define TS_NAME_LEN (MAXCOMLEN + sizeof(" td ") + sizeof(__XSTRING(UINT_MAX)))
+#define TDQ_NAME_LEN (sizeof("sched lock ") + sizeof(__XSTRING(MAXCPU)))
+#define TDQ_LOADNAME_LEN (sizeof("CPU ") + sizeof(__XSTRING(MAXCPU)) - 1 + sizeof(" load"))
+
+/*
+ * Thread scheduler specific section. All fields are protected
+ * by the thread lock.
+ */
+struct td_sched {
+ struct runq *ts_runq; /* Run-queue we're queued on. */
+ short ts_flags; /* TSF_* flags. */
+ u_char ts_cpu; /* CPU that we have affinity for. */
+ int ts_rltick; /* Real last tick, for affinity. */
+ int ts_slice; /* Ticks of slice remaining. */
+ u_int ts_slptime; /* Number of ticks we vol. slept */
+ u_int ts_runtime; /* Number of ticks we were running */
+ int ts_ltick; /* Last tick that we were running on */
+ int ts_ftick; /* First tick that we were running on */
+ int ts_ticks; /* Tick count */
+#ifdef KTR
+ char ts_name[TS_NAME_LEN];
+#endif
+};
+/* flags kept in ts_flags */
+#define TSF_BOUND 0x0001 /* Thread can not migrate. */
+#define TSF_XFERABLE 0x0002 /* Thread was added as transferable. */
+
+static struct td_sched td_sched0;
+
+#define THREAD_CAN_MIGRATE(td) ((td)->td_pinned == 0)
+#define THREAD_CAN_SCHED(td, cpu) \
+ CPU_ISSET((cpu), &(td)->td_cpuset->cs_mask)
+
+/*
+ * Priority ranges used for interactive and non-interactive timeshare
+ * threads. The timeshare priorities are split up into four ranges.
+ * The first range handles interactive threads. The last three ranges
+ * (NHALF, x, and NHALF) handle non-interactive threads with the outer
+ * ranges supporting nice values.
+ */
+#define PRI_TIMESHARE_RANGE (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1)
+#define PRI_INTERACT_RANGE ((PRI_TIMESHARE_RANGE - SCHED_PRI_NRESV) / 2)
+#define PRI_BATCH_RANGE (PRI_TIMESHARE_RANGE - PRI_INTERACT_RANGE)
+
+#define PRI_MIN_INTERACT PRI_MIN_TIMESHARE
+#define PRI_MAX_INTERACT (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE - 1)
+#define PRI_MIN_BATCH (PRI_MIN_TIMESHARE + PRI_INTERACT_RANGE)
+#define PRI_MAX_BATCH PRI_MAX_TIMESHARE
+
+/*
+ * Cpu percentage computation macros and defines.
+ *
+ * SCHED_TICK_SECS: Number of seconds to average the cpu usage across.
+ * SCHED_TICK_TARG: Number of hz ticks to average the cpu usage across.
+ * SCHED_TICK_MAX: Maximum number of ticks before scaling back.
+ * SCHED_TICK_SHIFT: Shift factor to avoid rounding away results.
+ * SCHED_TICK_HZ: Compute the number of hz ticks for a given ticks count.
+ * SCHED_TICK_TOTAL: Gives the amount of time we've been recording ticks.
+ */
+#define SCHED_TICK_SECS 10
+#define SCHED_TICK_TARG (hz * SCHED_TICK_SECS)
+#define SCHED_TICK_MAX (SCHED_TICK_TARG + hz)
+#define SCHED_TICK_SHIFT 10
+#define SCHED_TICK_HZ(ts) ((ts)->ts_ticks >> SCHED_TICK_SHIFT)
+#define SCHED_TICK_TOTAL(ts) (max((ts)->ts_ltick - (ts)->ts_ftick, hz))
+
+/*
+ * These macros determine priorities for non-interactive threads. They are
+ * assigned a priority based on their recent cpu utilization as expressed
+ * by the ratio of ticks to the tick total. NHALF priorities at the start
+ * and end of the MIN to MAX timeshare range are only reachable with negative
+ * or positive nice respectively.
+ *
+ * PRI_RANGE: Priority range for utilization dependent priorities.
+ * PRI_NRESV: Number of nice values.
+ * PRI_TICKS: Compute a priority in PRI_RANGE from the ticks count and total.
+ * PRI_NICE: Determines the part of the priority inherited from nice.
+ */
+#define SCHED_PRI_NRESV (PRIO_MAX - PRIO_MIN)
+#define SCHED_PRI_NHALF (SCHED_PRI_NRESV / 2)
+#define SCHED_PRI_MIN (PRI_MIN_BATCH + SCHED_PRI_NHALF)
+#define SCHED_PRI_MAX (PRI_MAX_BATCH - SCHED_PRI_NHALF)
+#define SCHED_PRI_RANGE (SCHED_PRI_MAX - SCHED_PRI_MIN + 1)
+#define SCHED_PRI_TICKS(ts) \
+ (SCHED_TICK_HZ((ts)) / \
+ (roundup(SCHED_TICK_TOTAL((ts)), SCHED_PRI_RANGE) / SCHED_PRI_RANGE))
+#define SCHED_PRI_NICE(nice) (nice)
+
+/*
+ * These determine the interactivity of a process. Interactivity differs from
+ * cpu utilization in that it expresses the voluntary time slept vs time ran
+ * while cpu utilization includes all time not running. This more accurately
+ * models the intent of the thread.
+ *
+ * SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate
+ * before throttling back.
+ * SLP_RUN_FORK: Maximum slp+run time to inherit at fork time.
+ * INTERACT_MAX: Maximum interactivity value. Smaller is better.
+ * INTERACT_THRESH: Threshold for placement on the current runq.
+ */
+#define SCHED_SLP_RUN_MAX ((hz * 5) << SCHED_TICK_SHIFT)
+#define SCHED_SLP_RUN_FORK ((hz / 2) << SCHED_TICK_SHIFT)
+#define SCHED_INTERACT_MAX (100)
+#define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2)
+#define SCHED_INTERACT_THRESH (30)
+
+/*
+ * These parameters determine the slice behavior for batch work.
+ */
+#define SCHED_SLICE_DEFAULT_DIVISOR 10 /* ~94 ms, 12 stathz ticks. */
+#define SCHED_SLICE_MIN_DIVISOR 6 /* DEFAULT/MIN = ~16 ms. */
+
+/* Flags kept in td_flags. */
+#define TDF_SLICEEND TDF_SCHED2 /* Thread time slice is over. */
+
+/*
+ * tickincr: Converts a stathz tick into a hz domain scaled by
+ * the shift factor. Without the shift the error rate
+ * due to rounding would be unacceptably high.
+ * realstathz: stathz is sometimes 0 and run off of hz.
+ * sched_slice: Runtime of each thread before rescheduling.
+ * preempt_thresh: Priority threshold for preemption and remote IPIs.
+ */
+static int sched_interact = SCHED_INTERACT_THRESH;
+static int tickincr = 8 << SCHED_TICK_SHIFT;
+static int realstathz = 127; /* reset during boot. */
+static int sched_slice = 10; /* reset during boot. */
+static int sched_slice_min = 1; /* reset during boot. */
+#ifdef PREEMPTION
+#ifdef FULL_PREEMPTION
+static int preempt_thresh = PRI_MAX_IDLE;
+#else
+static int preempt_thresh = PRI_MIN_KERN;
+#endif
+#else
+static int preempt_thresh = 0;
+#endif
+static int static_boost = PRI_MIN_BATCH;
+static int sched_idlespins = 10000;
+static int sched_idlespinthresh = -1;
+
+/*
+ * tdq - per processor runqs and statistics. All fields are protected by the
+ * tdq_lock. The load and lowpri may be accessed without to avoid excess
+ * locking in sched_pickcpu();
+ */
+struct tdq {
+ /*
+ * Ordered to improve efficiency of cpu_search() and switch().
+ * tdq_lock is padded to avoid false sharing with tdq_load and
+ * tdq_cpu_idle.
+ */
+ struct mtx_padalign tdq_lock; /* run queue lock. */
+ struct cpu_group *tdq_cg; /* Pointer to cpu topology. */
+ volatile int tdq_load; /* Aggregate load. */
+ volatile int tdq_cpu_idle; /* cpu_idle() is active. */
+ int tdq_sysload; /* For loadavg, !ITHD load. */
+ int tdq_transferable; /* Transferable thread count. */
+ short tdq_switchcnt; /* Switches this tick. */
+ short tdq_oldswitchcnt; /* Switches last tick. */
+ u_char tdq_lowpri; /* Lowest priority thread. */
+ u_char tdq_ipipending; /* IPI pending. */
+ u_char tdq_idx; /* Current insert index. */
+ u_char tdq_ridx; /* Current removal index. */
+ struct runq tdq_realtime; /* real-time run queue. */
+ struct runq tdq_timeshare; /* timeshare run queue. */
+ struct runq tdq_idle; /* Queue of IDLE threads. */
+ char tdq_name[TDQ_NAME_LEN];
+#ifdef KTR
+ char tdq_loadname[TDQ_LOADNAME_LEN];
+#endif
+} __aligned(64);
+
+/* Idle thread states and config. */
+#define TDQ_RUNNING 1
+#define TDQ_IDLE 2
+
+#ifdef SMP
+struct cpu_group *cpu_top; /* CPU topology */
+
+#define SCHED_AFFINITY_DEFAULT (max(1, hz / 1000))
+#define SCHED_AFFINITY(ts, t) ((ts)->ts_rltick > ticks - ((t) * affinity))
+
+/*
+ * Run-time tunables.
+ */
+static int rebalance = 1;
+static int balance_interval = 128; /* Default set in sched_initticks(). */
+static int affinity;
+static int steal_idle = 1;
+static int steal_thresh = 2;
+
+/*
+ * One thread queue per processor.
+ */
+static struct tdq tdq_cpu[MAXCPU];
+static struct tdq *balance_tdq;
+static int balance_ticks;
+static DPCPU_DEFINE(uint32_t, randomval);
+
+#define TDQ_SELF() (&tdq_cpu[PCPU_GET(cpuid)])
+#define TDQ_CPU(x) (&tdq_cpu[(x)])
+#define TDQ_ID(x) ((int)((x) - tdq_cpu))
+#else /* !SMP */
+static struct tdq tdq_cpu;
+
+#define TDQ_ID(x) (0)
+#define TDQ_SELF() (&tdq_cpu)
+#define TDQ_CPU(x) (&tdq_cpu)
+#endif
+
+#define TDQ_LOCK_ASSERT(t, type) mtx_assert(TDQ_LOCKPTR((t)), (type))
+#define TDQ_LOCK(t) mtx_lock_spin(TDQ_LOCKPTR((t)))
+#define TDQ_LOCK_FLAGS(t, f) mtx_lock_spin_flags(TDQ_LOCKPTR((t)), (f))
+#define TDQ_UNLOCK(t) mtx_unlock_spin(TDQ_LOCKPTR((t)))
+#define TDQ_LOCKPTR(t) ((struct mtx *)(&(t)->tdq_lock))
+
+static void sched_priority(struct thread *);
+static void sched_thread_priority(struct thread *, u_char);
+static int sched_interact_score(struct thread *);
+static void sched_interact_update(struct thread *);
+static void sched_interact_fork(struct thread *);
+static void sched_pctcpu_update(struct td_sched *, int);
+
+/* Operations on per processor queues */
+static struct thread *tdq_choose(struct tdq *);
+static void tdq_setup(struct tdq *);
+static void tdq_load_add(struct tdq *, struct thread *);
+static void tdq_load_rem(struct tdq *, struct thread *);
+static __inline void tdq_runq_add(struct tdq *, struct thread *, int);
+static __inline void tdq_runq_rem(struct tdq *, struct thread *);
+static inline int sched_shouldpreempt(int, int, int);
+void tdq_print(int cpu);
+static void runq_print(struct runq *rq);
+static void tdq_add(struct tdq *, struct thread *, int);
+#ifdef SMP
+static int tdq_move(struct tdq *, struct tdq *);
+static int tdq_idled(struct tdq *);
+static void tdq_notify(struct tdq *, struct thread *);
+static struct thread *tdq_steal(struct tdq *, int);
+static struct thread *runq_steal(struct runq *, int);
+static int sched_pickcpu(struct thread *, int);
+static void sched_balance(void);
+static int sched_balance_pair(struct tdq *, struct tdq *);
+static inline struct tdq *sched_setcpu(struct thread *, int, int);
+static inline void thread_unblock_switch(struct thread *, struct mtx *);
+static struct mtx *sched_switch_migrate(struct tdq *, struct thread *, int);
+static int sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS);
+static int sysctl_kern_sched_topology_spec_internal(struct sbuf *sb,
+ struct cpu_group *cg, int indent);
+#endif
+
+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);
+
+SDT_PROVIDER_DEFINE(sched);
+
+SDT_PROBE_DEFINE3(sched, , , change_pri, change-pri, "struct thread *",
+ "struct proc *", "uint8_t");
+SDT_PROBE_DEFINE3(sched, , , dequeue, dequeue, "struct thread *",
+ "struct proc *", "void *");
+SDT_PROBE_DEFINE4(sched, , , enqueue, enqueue, "struct thread *",
+ "struct proc *", "void *", "int");
+SDT_PROBE_DEFINE4(sched, , , lend_pri, lend-pri, "struct thread *",
+ "struct proc *", "uint8_t", "struct thread *");
+SDT_PROBE_DEFINE2(sched, , , load_change, load-change, "int", "int");
+SDT_PROBE_DEFINE2(sched, , , off_cpu, off-cpu, "struct thread *",
+ "struct proc *");
+SDT_PROBE_DEFINE(sched, , , on_cpu, on-cpu);
+SDT_PROBE_DEFINE(sched, , , remain_cpu, remain-cpu);
+SDT_PROBE_DEFINE2(sched, , , surrender, surrender, "struct thread *",
+ "struct proc *");
+
+/*
+ * Print the threads waiting on a run-queue.
+ */
+static void
+runq_print(struct runq *rq)
+{
+ struct rqhead *rqh;
+ struct thread *td;
+ int pri;
+ int j;
+ int i;
+
+ for (i = 0; i < RQB_LEN; i++) {
+ printf("\t\trunq bits %d 0x%zx\n",
+ i, rq->rq_status.rqb_bits[i]);
+ for (j = 0; j < RQB_BPW; j++)
+ if (rq->rq_status.rqb_bits[i] & (1ul << j)) {
+ pri = j + (i << RQB_L2BPW);
+ rqh = &rq->rq_queues[pri];
+ TAILQ_FOREACH(td, rqh, td_runq) {
+ printf("\t\t\ttd %p(%s) priority %d rqindex %d pri %d\n",
+ td, td->td_name, td->td_priority,
+ td->td_rqindex, pri);
+ }
+ }
+ }
+}
+
+/*
+ * Print the status of a per-cpu thread queue. Should be a ddb show cmd.
+ */
+void
+tdq_print(int cpu)
+{
+ struct tdq *tdq;
+
+ tdq = TDQ_CPU(cpu);
+
+ printf("tdq %d:\n", TDQ_ID(tdq));
+ printf("\tlock %p\n", TDQ_LOCKPTR(tdq));
+ printf("\tLock name: %s\n", tdq->tdq_name);
+ printf("\tload: %d\n", tdq->tdq_load);
+ printf("\tswitch cnt: %d\n", tdq->tdq_switchcnt);
+ printf("\told switch cnt: %d\n", tdq->tdq_oldswitchcnt);
+ printf("\ttimeshare idx: %d\n", tdq->tdq_idx);
+ printf("\ttimeshare ridx: %d\n", tdq->tdq_ridx);
+ printf("\tload transferable: %d\n", tdq->tdq_transferable);
+ printf("\tlowest priority: %d\n", tdq->tdq_lowpri);
+ printf("\trealtime runq:\n");
+ runq_print(&tdq->tdq_realtime);
+ printf("\ttimeshare runq:\n");
+ runq_print(&tdq->tdq_timeshare);
+ printf("\tidle runq:\n");
+ runq_print(&tdq->tdq_idle);
+}
+
+static inline int
+sched_shouldpreempt(int pri, int cpri, int remote)
+{
+ /*
+ * If the new priority is not better than the current priority there is
+ * nothing to do.
+ */
+ if (pri >= cpri)
+ return (0);
+ /*
+ * Always preempt idle.
+ */
+ if (cpri >= PRI_MIN_IDLE)
+ return (1);
+ /*
+ * If preemption is disabled don't preempt others.
+ */
+ if (preempt_thresh == 0)
+ return (0);
+ /*
+ * Preempt if we exceed the threshold.
+ */
+ if (pri <= preempt_thresh)
+ return (1);
+ /*
+ * If we're interactive or better and there is non-interactive
+ * or worse running preempt only remote processors.
+ */
+ if (remote && pri <= PRI_MAX_INTERACT && cpri > PRI_MAX_INTERACT)
+ return (1);
+ return (0);
+}
+
+/*
+ * Add a thread to the actual run-queue. Keeps transferable counts up to
+ * date with what is actually on the run-queue. Selects the correct
+ * queue position for timeshare threads.
+ */
+static __inline void
+tdq_runq_add(struct tdq *tdq, struct thread *td, int flags)
+{
+ struct td_sched *ts;
+ u_char pri;
+
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+
+ pri = td->td_priority;
+ ts = td->td_sched;
+ TD_SET_RUNQ(td);
+ if (THREAD_CAN_MIGRATE(td)) {
+ tdq->tdq_transferable++;
+ ts->ts_flags |= TSF_XFERABLE;
+ }
+ if (pri < PRI_MIN_BATCH) {
+ ts->ts_runq = &tdq->tdq_realtime;
+ } else if (pri <= PRI_MAX_BATCH) {
+ ts->ts_runq = &tdq->tdq_timeshare;
+ KASSERT(pri <= PRI_MAX_BATCH && pri >= PRI_MIN_BATCH,
+ ("Invalid priority %d on timeshare runq", pri));
+ /*
+ * This queue contains only priorities between MIN and MAX
+ * realtime. Use the whole queue to represent these values.
+ */
+ if ((flags & (SRQ_BORROWING|SRQ_PREEMPTED)) == 0) {
+ pri = RQ_NQS * (pri - PRI_MIN_BATCH) / PRI_BATCH_RANGE;
+ pri = (pri + tdq->tdq_idx) % RQ_NQS;
+ /*
+ * This effectively shortens the queue by one so we
+ * can have a one slot difference between idx and
+ * ridx while we wait for threads to drain.
+ */
+ if (tdq->tdq_ridx != tdq->tdq_idx &&
+ pri == tdq->tdq_ridx)
+ pri = (unsigned char)(pri - 1) % RQ_NQS;
+ } else
+ pri = tdq->tdq_ridx;
+ runq_add_pri(ts->ts_runq, td, pri, flags);
+ return;
+ } else
+ ts->ts_runq = &tdq->tdq_idle;
+ runq_add(ts->ts_runq, td, flags);
+}
+
+/*
+ * Remove a thread from a run-queue. This typically happens when a thread
+ * is selected to run. Running threads are not on the queue and the
+ * transferable count does not reflect them.
+ */
+static __inline void
+tdq_runq_rem(struct tdq *tdq, struct thread *td)
+{
+ struct td_sched *ts;
+
+ ts = td->td_sched;
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ KASSERT(ts->ts_runq != NULL,
+ ("tdq_runq_remove: thread %p null ts_runq", td));
+ if (ts->ts_flags & TSF_XFERABLE) {
+ tdq->tdq_transferable--;
+ ts->ts_flags &= ~TSF_XFERABLE;
+ }
+ if (ts->ts_runq == &tdq->tdq_timeshare) {
+ if (tdq->tdq_idx != tdq->tdq_ridx)
+ runq_remove_idx(ts->ts_runq, td, &tdq->tdq_ridx);
+ else
+ runq_remove_idx(ts->ts_runq, td, NULL);
+ } else
+ runq_remove(ts->ts_runq, td);
+}
+
+/*
+ * Load is maintained for all threads RUNNING and ON_RUNQ. Add the load
+ * for this thread to the referenced thread queue.
+ */
+static void
+tdq_load_add(struct tdq *tdq, struct thread *td)
+{
+
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+
+ tdq->tdq_load++;
+ if ((td->td_flags & TDF_NOLOAD) == 0)
+ tdq->tdq_sysload++;
+ KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
+ SDT_PROBE2(sched, , , load_change, (int)TDQ_ID(tdq), tdq->tdq_load);
+}
+
+/*
+ * Remove the load from a thread that is transitioning to a sleep state or
+ * exiting.
+ */
+static void
+tdq_load_rem(struct tdq *tdq, struct thread *td)
+{
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ KASSERT(tdq->tdq_load != 0,
+ ("tdq_load_rem: Removing with 0 load on queue %d", TDQ_ID(tdq)));
+
+ tdq->tdq_load--;
+ if ((td->td_flags & TDF_NOLOAD) == 0)
+ tdq->tdq_sysload--;
+ KTR_COUNTER0(KTR_SCHED, "load", tdq->tdq_loadname, tdq->tdq_load);
+ SDT_PROBE2(sched, , , load_change, (int)TDQ_ID(tdq), tdq->tdq_load);
+}
+
+/*
+ * Bound timeshare latency by decreasing slice size as load increases. We
+ * consider the maximum latency as the sum of the threads waiting to run
+ * aside from curthread and target no more than sched_slice latency but
+ * no less than sched_slice_min runtime.
+ */
+static inline int
+tdq_slice(struct tdq *tdq)
+{
+ int load;
+
+ /*
+ * It is safe to use sys_load here because this is called from
+ * contexts where timeshare threads are running and so there
+ * cannot be higher priority load in the system.
+ */
+ load = tdq->tdq_sysload - 1;
+ if (load >= SCHED_SLICE_MIN_DIVISOR)
+ return (sched_slice_min);
+ if (load <= 1)
+ return (sched_slice);
+ return (sched_slice / load);
+}
+
+/*
+ * Set lowpri to its exact value by searching the run-queue and
+ * evaluating curthread. curthread may be passed as an optimization.
+ */
+static void
+tdq_setlowpri(struct tdq *tdq, struct thread *ctd)
+{
+ struct thread *td;
+
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ if (ctd == NULL)
+ ctd = pcpu_find(TDQ_ID(tdq))->pc_curthread;
+ td = tdq_choose(tdq);
+ if (td == NULL || td->td_priority > ctd->td_priority)
+ tdq->tdq_lowpri = ctd->td_priority;
+ else
+ tdq->tdq_lowpri = td->td_priority;
+}
+
+#ifdef SMP
+struct cpu_search {
+ cpuset_t cs_mask;
+ u_int cs_prefer;
+ int cs_pri; /* Min priority for low. */
+ int cs_limit; /* Max load for low, min load for high. */
+ int cs_cpu;
+ int cs_load;
+};
+
+#define CPU_SEARCH_LOWEST 0x1
+#define CPU_SEARCH_HIGHEST 0x2
+#define CPU_SEARCH_BOTH (CPU_SEARCH_LOWEST|CPU_SEARCH_HIGHEST)
+
+#define CPUSET_FOREACH(cpu, mask) \
+ for ((cpu) = 0; (cpu) <= mp_maxid; (cpu)++) \
+ if (CPU_ISSET(cpu, &mask))
+
+static __inline int cpu_search(const struct cpu_group *cg, struct cpu_search *low,
+ struct cpu_search *high, const int match);
+int cpu_search_lowest(const struct cpu_group *cg, struct cpu_search *low);
+int cpu_search_highest(const struct cpu_group *cg, struct cpu_search *high);
+int cpu_search_both(const struct cpu_group *cg, struct cpu_search *low,
+ struct cpu_search *high);
+
+/*
+ * Search the tree of cpu_groups for the lowest or highest loaded cpu
+ * according to the match argument. This routine actually compares the
+ * load on all paths through the tree and finds the least loaded cpu on
+ * the least loaded path, which may differ from the least loaded cpu in
+ * the system. This balances work among caches and busses.
+ *
+ * This inline is instantiated in three forms below using constants for the
+ * match argument. It is reduced to the minimum set for each case. It is
+ * also recursive to the depth of the tree.
+ */
+static __inline int
+cpu_search(const struct cpu_group *cg, struct cpu_search *low,
+ struct cpu_search *high, const int match)
+{
+ struct cpu_search lgroup;
+ struct cpu_search hgroup;
+ cpuset_t cpumask;
+ struct cpu_group *child;
+ struct tdq *tdq;
+ int cpu, i, hload, lload, load, total, rnd, *rndptr;
+
+ total = 0;
+ cpumask = cg->cg_mask;
+ if (match & CPU_SEARCH_LOWEST) {
+ lload = INT_MAX;
+ lgroup = *low;
+ }
+ if (match & CPU_SEARCH_HIGHEST) {
+ hload = INT_MIN;
+ hgroup = *high;
+ }
+
+ /* Iterate through the child CPU groups and then remaining CPUs. */
+ for (i = cg->cg_children, cpu = mp_maxid; i >= 0; ) {
+ if (i == 0) {
+ while (cpu >= 0 && !CPU_ISSET(cpu, &cpumask))
+ cpu--;
+ if (cpu < 0)
+ break;
+ child = NULL;
+ } else
+ child = &cg->cg_child[i - 1];
+
+ if (match & CPU_SEARCH_LOWEST)
+ lgroup.cs_cpu = -1;
+ if (match & CPU_SEARCH_HIGHEST)
+ hgroup.cs_cpu = -1;
+ if (child) { /* Handle child CPU group. */
+ CPU_NAND(&cpumask, &child->cg_mask);
+ switch (match) {
+ case CPU_SEARCH_LOWEST:
+ load = cpu_search_lowest(child, &lgroup);
+ break;
+ case CPU_SEARCH_HIGHEST:
+ load = cpu_search_highest(child, &hgroup);
+ break;
+ case CPU_SEARCH_BOTH:
+ load = cpu_search_both(child, &lgroup, &hgroup);
+ break;
+ }
+ } else { /* Handle child CPU. */
+ tdq = TDQ_CPU(cpu);
+ load = tdq->tdq_load * 256;
+ rndptr = DPCPU_PTR(randomval);
+ rnd = (*rndptr = *rndptr * 69069 + 5) >> 26;
+ if (match & CPU_SEARCH_LOWEST) {
+ if (cpu == low->cs_prefer)
+ load -= 64;
+ /* If that CPU is allowed and get data. */
+ if (tdq->tdq_lowpri > lgroup.cs_pri &&
+ tdq->tdq_load <= lgroup.cs_limit &&
+ CPU_ISSET(cpu, &lgroup.cs_mask)) {
+ lgroup.cs_cpu = cpu;
+ lgroup.cs_load = load - rnd;
+ }
+ }
+ if (match & CPU_SEARCH_HIGHEST)
+ if (tdq->tdq_load >= hgroup.cs_limit &&
+ tdq->tdq_transferable &&
+ CPU_ISSET(cpu, &hgroup.cs_mask)) {
+ hgroup.cs_cpu = cpu;
+ hgroup.cs_load = load - rnd;
+ }
+ }
+ total += load;
+
+ /* We have info about child item. Compare it. */
+ if (match & CPU_SEARCH_LOWEST) {
+ if (lgroup.cs_cpu >= 0 &&
+ (load < lload ||
+ (load == lload && lgroup.cs_load < low->cs_load))) {
+ lload = load;
+ low->cs_cpu = lgroup.cs_cpu;
+ low->cs_load = lgroup.cs_load;
+ }
+ }
+ if (match & CPU_SEARCH_HIGHEST)
+ if (hgroup.cs_cpu >= 0 &&
+ (load > hload ||
+ (load == hload && hgroup.cs_load > high->cs_load))) {
+ hload = load;
+ high->cs_cpu = hgroup.cs_cpu;
+ high->cs_load = hgroup.cs_load;
+ }
+ if (child) {
+ i--;
+ if (i == 0 && CPU_EMPTY(&cpumask))
+ break;
+ } else
+ cpu--;
+ }
+ return (total);
+}
+
+/*
+ * cpu_search instantiations must pass constants to maintain the inline
+ * optimization.
+ */
+int
+cpu_search_lowest(const struct cpu_group *cg, struct cpu_search *low)
+{
+ return cpu_search(cg, low, NULL, CPU_SEARCH_LOWEST);
+}
+
+int
+cpu_search_highest(const struct cpu_group *cg, struct cpu_search *high)
+{
+ return cpu_search(cg, NULL, high, CPU_SEARCH_HIGHEST);
+}
+
+int
+cpu_search_both(const struct cpu_group *cg, struct cpu_search *low,
+ struct cpu_search *high)
+{
+ return cpu_search(cg, low, high, CPU_SEARCH_BOTH);
+}
+
+/*
+ * Find the cpu with the least load via the least loaded path that has a
+ * lowpri greater than pri pri. A pri of -1 indicates any priority is
+ * acceptable.
+ */
+static inline int
+sched_lowest(const struct cpu_group *cg, cpuset_t mask, int pri, int maxload,
+ int prefer)
+{
+ struct cpu_search low;
+
+ low.cs_cpu = -1;
+ low.cs_prefer = prefer;
+ low.cs_mask = mask;
+ low.cs_pri = pri;
+ low.cs_limit = maxload;
+ cpu_search_lowest(cg, &low);
+ return low.cs_cpu;
+}
+
+/*
+ * Find the cpu with the highest load via the highest loaded path.
+ */
+static inline int
+sched_highest(const struct cpu_group *cg, cpuset_t mask, int minload)
+{
+ struct cpu_search high;
+
+ high.cs_cpu = -1;
+ high.cs_mask = mask;
+ high.cs_limit = minload;
+ cpu_search_highest(cg, &high);
+ return high.cs_cpu;
+}
+
+/*
+ * Simultaneously find the highest and lowest loaded cpu reachable via
+ * cg.
+ */
+static inline void
+sched_both(const struct cpu_group *cg, cpuset_t mask, int *lowcpu, int *highcpu)
+{
+ struct cpu_search high;
+ struct cpu_search low;
+
+ low.cs_cpu = -1;
+ low.cs_prefer = -1;
+ low.cs_pri = -1;
+ low.cs_limit = INT_MAX;
+ low.cs_mask = mask;
+ high.cs_cpu = -1;
+ high.cs_limit = -1;
+ high.cs_mask = mask;
+ cpu_search_both(cg, &low, &high);
+ *lowcpu = low.cs_cpu;
+ *highcpu = high.cs_cpu;
+ return;
+}
+
+static void
+sched_balance_group(struct cpu_group *cg)
+{
+ cpuset_t hmask, lmask;
+ int high, low, anylow;
+
+ CPU_FILL(&hmask);
+ for (;;) {
+ high = sched_highest(cg, hmask, 1);
+ /* Stop if there is no more CPU with transferrable threads. */
+ if (high == -1)
+ break;
+ CPU_CLR(high, &hmask);
+ CPU_COPY(&hmask, &lmask);
+ /* Stop if there is no more CPU left for low. */
+ if (CPU_EMPTY(&lmask))
+ break;
+ anylow = 1;
+nextlow:
+ low = sched_lowest(cg, lmask, -1,
+ TDQ_CPU(high)->tdq_load - 1, high);
+ /* Stop if we looked well and found no less loaded CPU. */
+ if (anylow && low == -1)
+ break;
+ /* Go to next high if we found no less loaded CPU. */
+ if (low == -1)
+ continue;
+ /* Transfer thread from high to low. */
+ if (sched_balance_pair(TDQ_CPU(high), TDQ_CPU(low))) {
+ /* CPU that got thread can no longer be a donor. */
+ CPU_CLR(low, &hmask);
+ } else {
+ /*
+ * If failed, then there is no threads on high
+ * that can run on this low. Drop low from low
+ * mask and look for different one.
+ */
+ CPU_CLR(low, &lmask);
+ anylow = 0;
+ goto nextlow;
+ }
+ }
+}
+
+static void
+sched_balance(void)
+{
+ struct tdq *tdq;
+
+ /*
+ * Select a random time between .5 * balance_interval and
+ * 1.5 * balance_interval.
+ */
+ balance_ticks = max(balance_interval / 2, 1);
+ balance_ticks += random() % balance_interval;
+ if (smp_started == 0 || rebalance == 0)
+ return;
+ tdq = TDQ_SELF();
+ TDQ_UNLOCK(tdq);
+ sched_balance_group(cpu_top);
+ TDQ_LOCK(tdq);
+}
+
+/*
+ * Lock two thread queues using their address to maintain lock order.
+ */
+static void
+tdq_lock_pair(struct tdq *one, struct tdq *two)
+{
+ if (one < two) {
+ TDQ_LOCK(one);
+ TDQ_LOCK_FLAGS(two, MTX_DUPOK);
+ } else {
+ TDQ_LOCK(two);
+ TDQ_LOCK_FLAGS(one, MTX_DUPOK);
+ }
+}
+
+/*
+ * Unlock two thread queues. Order is not important here.
+ */
+static void
+tdq_unlock_pair(struct tdq *one, struct tdq *two)
+{
+ TDQ_UNLOCK(one);
+ TDQ_UNLOCK(two);
+}
+
+/*
+ * Transfer load between two imbalanced thread queues.
+ */
+static int
+sched_balance_pair(struct tdq *high, struct tdq *low)
+{
+ int moved;
+ int cpu;
+
+ tdq_lock_pair(high, low);
+ moved = 0;
+ /*
+ * Determine what the imbalance is and then adjust that to how many
+ * threads we actually have to give up (transferable).
+ */
+ if (high->tdq_transferable != 0 && high->tdq_load > low->tdq_load &&
+ (moved = tdq_move(high, low)) > 0) {
+ /*
+ * In case the target isn't the current cpu IPI it to force a
+ * reschedule with the new workload.
+ */
+ cpu = TDQ_ID(low);
+ if (cpu != PCPU_GET(cpuid))
+ ipi_cpu(cpu, IPI_PREEMPT);
+ }
+ tdq_unlock_pair(high, low);
+ return (moved);
+}
+
+/*
+ * Move a thread from one thread queue to another.
+ */
+static int
+tdq_move(struct tdq *from, struct tdq *to)
+{
+ struct td_sched *ts;
+ struct thread *td;
+ struct tdq *tdq;
+ int cpu;
+
+ TDQ_LOCK_ASSERT(from, MA_OWNED);
+ TDQ_LOCK_ASSERT(to, MA_OWNED);
+
+ tdq = from;
+ cpu = TDQ_ID(to);
+ td = tdq_steal(tdq, cpu);
+ if (td == NULL)
+ return (0);
+ ts = td->td_sched;
+ /*
+ * Although the run queue is locked the thread may be blocked. Lock
+ * it to clear this and acquire the run-queue lock.
+ */
+ thread_lock(td);
+ /* Drop recursive lock on from acquired via thread_lock(). */
+ TDQ_UNLOCK(from);
+ sched_rem(td);
+ ts->ts_cpu = cpu;
+ td->td_lock = TDQ_LOCKPTR(to);
+ tdq_add(to, td, SRQ_YIELDING);
+ return (1);
+}
+
+/*
+ * This tdq has idled. Try to steal a thread from another cpu and switch
+ * to it.
+ */
+static int
+tdq_idled(struct tdq *tdq)
+{
+ struct cpu_group *cg;
+ struct tdq *steal;
+ cpuset_t mask;
+ int thresh;
+ int cpu;
+
+ if (smp_started == 0 || steal_idle == 0)
+ return (1);
+ CPU_FILL(&mask);
+ CPU_CLR(PCPU_GET(cpuid), &mask);
+ /* We don't want to be preempted while we're iterating. */
+ spinlock_enter();
+ for (cg = tdq->tdq_cg; cg != NULL; ) {
+ if ((cg->cg_flags & CG_FLAG_THREAD) == 0)
+ thresh = steal_thresh;
+ else
+ thresh = 1;
+ cpu = sched_highest(cg, mask, thresh);
+ if (cpu == -1) {
+ cg = cg->cg_parent;
+ continue;
+ }
+ steal = TDQ_CPU(cpu);
+ CPU_CLR(cpu, &mask);
+ tdq_lock_pair(tdq, steal);
+ if (steal->tdq_load < thresh || steal->tdq_transferable == 0) {
+ tdq_unlock_pair(tdq, steal);
+ continue;
+ }
+ /*
+ * If a thread was added while interrupts were disabled don't
+ * steal one here. If we fail to acquire one due to affinity
+ * restrictions loop again with this cpu removed from the
+ * set.
+ */
+ if (tdq->tdq_load == 0 && tdq_move(steal, tdq) == 0) {
+ tdq_unlock_pair(tdq, steal);
+ continue;
+ }
+ spinlock_exit();
+ TDQ_UNLOCK(steal);
+ mi_switch(SW_VOL | SWT_IDLE, NULL);
+ thread_unlock(curthread);
+
+ return (0);
+ }
+ spinlock_exit();
+ return (1);
+}
+
+/*
+ * Notify a remote cpu of new work. Sends an IPI if criteria are met.
+ */
+static void
+tdq_notify(struct tdq *tdq, struct thread *td)
+{
+ struct thread *ctd;
+ int pri;
+ int cpu;
+
+ if (tdq->tdq_ipipending)
+ return;
+ cpu = td->td_sched->ts_cpu;
+ pri = td->td_priority;
+ ctd = pcpu_find(cpu)->pc_curthread;
+ if (!sched_shouldpreempt(pri, ctd->td_priority, 1))
+ return;
+ if (TD_IS_IDLETHREAD(ctd)) {
+ /*
+ * If the MD code has an idle wakeup routine try that before
+ * falling back to IPI.
+ */
+ if (!tdq->tdq_cpu_idle || cpu_idle_wakeup(cpu))
+ return;
+ }
+ tdq->tdq_ipipending = 1;
+ ipi_cpu(cpu, IPI_PREEMPT);
+}
+
+/*
+ * Steals load from a timeshare queue. Honors the rotating queue head
+ * index.
+ */
+static struct thread *
+runq_steal_from(struct runq *rq, int cpu, u_char start)
+{
+ struct rqbits *rqb;
+ struct rqhead *rqh;
+ struct thread *td, *first;
+ int bit;
+ int pri;
+ int i;
+
+ rqb = &rq->rq_status;
+ bit = start & (RQB_BPW -1);
+ pri = 0;
+ first = NULL;
+again:
+ for (i = RQB_WORD(start); i < RQB_LEN; bit = 0, i++) {
+ if (rqb->rqb_bits[i] == 0)
+ continue;
+ if (bit != 0) {
+ for (pri = bit; pri < RQB_BPW; pri++)
+ if (rqb->rqb_bits[i] & (1ul << pri))
+ break;
+ if (pri >= RQB_BPW)
+ continue;
+ } else
+ pri = RQB_FFS(rqb->rqb_bits[i]);
+ pri += (i << RQB_L2BPW);
+ rqh = &rq->rq_queues[pri];
+ TAILQ_FOREACH(td, rqh, td_runq) {
+ if (first && THREAD_CAN_MIGRATE(td) &&
+ THREAD_CAN_SCHED(td, cpu))
+ return (td);
+ first = td;
+ }
+ }
+ if (start != 0) {
+ start = 0;
+ goto again;
+ }
+
+ if (first && THREAD_CAN_MIGRATE(first) &&
+ THREAD_CAN_SCHED(first, cpu))
+ return (first);
+ return (NULL);
+}
+
+/*
+ * Steals load from a standard linear queue.
+ */
+static struct thread *
+runq_steal(struct runq *rq, int cpu)
+{
+ struct rqhead *rqh;
+ struct rqbits *rqb;
+ struct thread *td;
+ int word;
+ int bit;
+
+ rqb = &rq->rq_status;
+ for (word = 0; word < RQB_LEN; word++) {
+ if (rqb->rqb_bits[word] == 0)
+ continue;
+ for (bit = 0; bit < RQB_BPW; bit++) {
+ if ((rqb->rqb_bits[word] & (1ul << bit)) == 0)
+ continue;
+ rqh = &rq->rq_queues[bit + (word << RQB_L2BPW)];
+ TAILQ_FOREACH(td, rqh, td_runq)
+ if (THREAD_CAN_MIGRATE(td) &&
+ THREAD_CAN_SCHED(td, cpu))
+ return (td);
+ }
+ }
+ return (NULL);
+}
+
+/*
+ * Attempt to steal a thread in priority order from a thread queue.
+ */
+static struct thread *
+tdq_steal(struct tdq *tdq, int cpu)
+{
+ struct thread *td;
+
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ if ((td = runq_steal(&tdq->tdq_realtime, cpu)) != NULL)
+ return (td);
+ if ((td = runq_steal_from(&tdq->tdq_timeshare,
+ cpu, tdq->tdq_ridx)) != NULL)
+ return (td);
+ return (runq_steal(&tdq->tdq_idle, cpu));
+}
+
+/*
+ * Sets the thread lock and ts_cpu to match the requested cpu. Unlocks the
+ * current lock and returns with the assigned queue locked.
+ */
+static inline struct tdq *
+sched_setcpu(struct thread *td, int cpu, int flags)
+{
+
+ struct tdq *tdq;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ tdq = TDQ_CPU(cpu);
+ td->td_sched->ts_cpu = cpu;
+ /*
+ * If the lock matches just return the queue.
+ */
+ if (td->td_lock == TDQ_LOCKPTR(tdq))
+ return (tdq);
+#ifdef notyet
+ /*
+ * If the thread isn't running its lockptr is a
+ * turnstile or a sleepqueue. We can just lock_set without
+ * blocking.
+ */
+ if (TD_CAN_RUN(td)) {
+ TDQ_LOCK(tdq);
+ thread_lock_set(td, TDQ_LOCKPTR(tdq));
+ return (tdq);
+ }
+#endif
+ /*
+ * The hard case, migration, we need to block the thread first to
+ * prevent order reversals with other cpus locks.
+ */
+ spinlock_enter();
+ thread_lock_block(td);
+ TDQ_LOCK(tdq);
+ thread_lock_unblock(td, TDQ_LOCKPTR(tdq));
+ spinlock_exit();
+ return (tdq);
+}
+
+SCHED_STAT_DEFINE(pickcpu_intrbind, "Soft interrupt binding");
+SCHED_STAT_DEFINE(pickcpu_idle_affinity, "Picked idle cpu based on affinity");
+SCHED_STAT_DEFINE(pickcpu_affinity, "Picked cpu based on affinity");
+SCHED_STAT_DEFINE(pickcpu_lowest, "Selected lowest load");
+SCHED_STAT_DEFINE(pickcpu_local, "Migrated to current cpu");
+SCHED_STAT_DEFINE(pickcpu_migration, "Selection may have caused migration");
+
+static int
+sched_pickcpu(struct thread *td, int flags)
+{
+ struct cpu_group *cg, *ccg;
+ struct td_sched *ts;
+ struct tdq *tdq;
+ cpuset_t mask;
+ int cpu, pri, self;
+
+ self = PCPU_GET(cpuid);
+ ts = td->td_sched;
+ if (smp_started == 0)
+ return (self);
+ /*
+ * Don't migrate a running thread from sched_switch().
+ */
+ if ((flags & SRQ_OURSELF) || !THREAD_CAN_MIGRATE(td))
+ return (ts->ts_cpu);
+ /*
+ * Prefer to run interrupt threads on the processors that generate
+ * the interrupt.
+ */
+ pri = td->td_priority;
+ if (td->td_priority <= PRI_MAX_ITHD && THREAD_CAN_SCHED(td, self) &&
+ curthread->td_intr_nesting_level && ts->ts_cpu != self) {
+ SCHED_STAT_INC(pickcpu_intrbind);
+ ts->ts_cpu = self;
+ if (TDQ_CPU(self)->tdq_lowpri > pri) {
+ SCHED_STAT_INC(pickcpu_affinity);
+ return (ts->ts_cpu);
+ }
+ }
+ /*
+ * If the thread can run on the last cpu and the affinity has not
+ * expired or it is idle run it there.
+ */
+ tdq = TDQ_CPU(ts->ts_cpu);
+ cg = tdq->tdq_cg;
+ if (THREAD_CAN_SCHED(td, ts->ts_cpu) &&
+ tdq->tdq_lowpri >= PRI_MIN_IDLE &&
+ SCHED_AFFINITY(ts, CG_SHARE_L2)) {
+ if (cg->cg_flags & CG_FLAG_THREAD) {
+ CPUSET_FOREACH(cpu, cg->cg_mask) {
+ if (TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE)
+ break;
+ }
+ } else
+ cpu = INT_MAX;
+ if (cpu > mp_maxid) {
+ SCHED_STAT_INC(pickcpu_idle_affinity);
+ return (ts->ts_cpu);
+ }
+ }
+ /*
+ * Search for the last level cache CPU group in the tree.
+ * Skip caches with expired affinity time and SMT groups.
+ * Affinity to higher level caches will be handled less aggressively.
+ */
+ for (ccg = NULL; cg != NULL; cg = cg->cg_parent) {
+ if (cg->cg_flags & CG_FLAG_THREAD)
+ continue;
+ if (!SCHED_AFFINITY(ts, cg->cg_level))
+ continue;
+ ccg = cg;
+ }
+ if (ccg != NULL)
+ cg = ccg;
+ cpu = -1;
+ /* Search the group for the less loaded idle CPU we can run now. */
+ mask = td->td_cpuset->cs_mask;
+ if (cg != NULL && cg != cpu_top &&
+ CPU_CMP(&cg->cg_mask, &cpu_top->cg_mask) != 0)
+ cpu = sched_lowest(cg, mask, max(pri, PRI_MAX_TIMESHARE),
+ INT_MAX, ts->ts_cpu);
+ /* Search globally for the less loaded CPU we can run now. */
+ if (cpu == -1)
+ cpu = sched_lowest(cpu_top, mask, pri, INT_MAX, ts->ts_cpu);
+ /* Search globally for the less loaded CPU. */
+ if (cpu == -1)
+ cpu = sched_lowest(cpu_top, mask, -1, INT_MAX, ts->ts_cpu);
+ KASSERT(cpu != -1, ("sched_pickcpu: Failed to find a cpu."));
+ /*
+ * Compare the lowest loaded cpu to current cpu.
+ */
+ if (THREAD_CAN_SCHED(td, self) && TDQ_CPU(self)->tdq_lowpri > pri &&
+ TDQ_CPU(cpu)->tdq_lowpri < PRI_MIN_IDLE &&
+ TDQ_CPU(self)->tdq_load <= TDQ_CPU(cpu)->tdq_load + 1) {
+ SCHED_STAT_INC(pickcpu_local);
+ cpu = self;
+ } else
+ SCHED_STAT_INC(pickcpu_lowest);
+ if (cpu != ts->ts_cpu)
+ SCHED_STAT_INC(pickcpu_migration);
+ return (cpu);
+}
+#endif
+
+/*
+ * Pick the highest priority task we have and return it.
+ */
+static struct thread *
+tdq_choose(struct tdq *tdq)
+{
+ struct thread *td;
+
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ td = runq_choose(&tdq->tdq_realtime);
+ if (td != NULL)
+ return (td);
+ td = runq_choose_from(&tdq->tdq_timeshare, tdq->tdq_ridx);
+ if (td != NULL) {
+ KASSERT(td->td_priority >= PRI_MIN_BATCH,
+ ("tdq_choose: Invalid priority on timeshare queue %d",
+ td->td_priority));
+ return (td);
+ }
+ td = runq_choose(&tdq->tdq_idle);
+ if (td != NULL) {
+ KASSERT(td->td_priority >= PRI_MIN_IDLE,
+ ("tdq_choose: Invalid priority on idle queue %d",
+ td->td_priority));
+ return (td);
+ }
+
+ return (NULL);
+}
+
+/*
+ * Initialize a thread queue.
+ */
+static void
+tdq_setup(struct tdq *tdq)
+{
+
+ if (bootverbose)
+ printf("ULE: setup cpu %d\n", TDQ_ID(tdq));
+ runq_init(&tdq->tdq_realtime);
+ runq_init(&tdq->tdq_timeshare);
+ runq_init(&tdq->tdq_idle);
+ snprintf(tdq->tdq_name, sizeof(tdq->tdq_name),
+ "sched lock %d", (int)TDQ_ID(tdq));
+ mtx_init(&tdq->tdq_lock, tdq->tdq_name, "sched lock",
+ MTX_SPIN | MTX_RECURSE);
+#ifdef KTR
+ snprintf(tdq->tdq_loadname, sizeof(tdq->tdq_loadname),
+ "CPU %d load", (int)TDQ_ID(tdq));
+#endif
+}
+
+#ifdef SMP
+static void
+sched_setup_smp(void)
+{
+ struct tdq *tdq;
+ int i;
+
+ cpu_top = smp_topo();
+ CPU_FOREACH(i) {
+ tdq = TDQ_CPU(i);
+ tdq_setup(tdq);
+ tdq->tdq_cg = smp_topo_find(cpu_top, i);
+ if (tdq->tdq_cg == NULL)
+ panic("Can't find cpu group for %d\n", i);
+ }
+ balance_tdq = TDQ_SELF();
+ sched_balance();
+}
+#endif
+
+/*
+ * Setup the thread queues and initialize the topology based on MD
+ * information.
+ */
+static void
+sched_setup(void *dummy)
+{
+ struct tdq *tdq;
+
+ tdq = TDQ_SELF();
+#ifdef SMP
+ sched_setup_smp();
+#else
+ tdq_setup(tdq);
+#endif
+
+ /* Add thread0's load since it's running. */
+ TDQ_LOCK(tdq);
+ thread0.td_lock = TDQ_LOCKPTR(TDQ_SELF());
+ tdq_load_add(tdq, &thread0);
+ tdq->tdq_lowpri = thread0.td_priority;
+ TDQ_UNLOCK(tdq);
+}
+
+/*
+ * This routine determines time constants after stathz and hz are setup.
+ */
+/* ARGSUSED */
+static void
+sched_initticks(void *dummy)
+{
+ int incr;
+
+ realstathz = stathz ? stathz : hz;
+ sched_slice = realstathz / SCHED_SLICE_DEFAULT_DIVISOR;
+ sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR;
+ hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
+ realstathz);
+
+ /*
+ * tickincr is shifted out by 10 to avoid rounding errors due to
+ * hz not being evenly divisible by stathz on all platforms.
+ */
+ incr = (hz << SCHED_TICK_SHIFT) / realstathz;
+ /*
+ * This does not work for values of stathz that are more than
+ * 1 << SCHED_TICK_SHIFT * hz. In practice this does not happen.
+ */
+ if (incr == 0)
+ incr = 1;
+ tickincr = incr;
+#ifdef SMP
+ /*
+ * Set the default balance interval now that we know
+ * what realstathz is.
+ */
+ balance_interval = realstathz;
+ affinity = SCHED_AFFINITY_DEFAULT;
+#endif
+ if (sched_idlespinthresh < 0)
+ sched_idlespinthresh = 2 * max(10000, 6 * hz) / realstathz;
+}
+
+
+/*
+ * This is the core of the interactivity algorithm. Determines a score based
+ * on past behavior. It is the ratio of sleep time to run time scaled to
+ * a [0, 100] integer. This is the voluntary sleep time of a process, which
+ * differs from the cpu usage because it does not account for time spent
+ * waiting on a run-queue. Would be prettier if we had floating point.
+ */
+static int
+sched_interact_score(struct thread *td)
+{
+ struct td_sched *ts;
+ int div;
+
+ ts = td->td_sched;
+ /*
+ * The score is only needed if this is likely to be an interactive
+ * task. Don't go through the expense of computing it if there's
+ * no chance.
+ */
+ if (sched_interact <= SCHED_INTERACT_HALF &&
+ ts->ts_runtime >= ts->ts_slptime)
+ return (SCHED_INTERACT_HALF);
+
+ if (ts->ts_runtime > ts->ts_slptime) {
+ div = max(1, ts->ts_runtime / SCHED_INTERACT_HALF);
+ return (SCHED_INTERACT_HALF +
+ (SCHED_INTERACT_HALF - (ts->ts_slptime / div)));
+ }
+ if (ts->ts_slptime > ts->ts_runtime) {
+ div = max(1, ts->ts_slptime / SCHED_INTERACT_HALF);
+ return (ts->ts_runtime / div);
+ }
+ /* runtime == slptime */
+ if (ts->ts_runtime)
+ return (SCHED_INTERACT_HALF);
+
+ /*
+ * This can happen if slptime and runtime are 0.
+ */
+ return (0);
+
+}
+
+/*
+ * Scale the scheduling priority according to the "interactivity" of this
+ * process.
+ */
+static void
+sched_priority(struct thread *td)
+{
+ int score;
+ int pri;
+
+ if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE)
+ return;
+ /*
+ * If the score is interactive we place the thread in the realtime
+ * queue with a priority that is less than kernel and interrupt
+ * priorities. These threads are not subject to nice restrictions.
+ *
+ * Scores greater than this are placed on the normal timeshare queue
+ * where the priority is partially decided by the most recent cpu
+ * utilization and the rest is decided by nice value.
+ *
+ * The nice value of the process has a linear effect on the calculated
+ * score. Negative nice values make it easier for a thread to be
+ * considered interactive.
+ */
+ score = imax(0, sched_interact_score(td) + td->td_proc->p_nice);
+ if (score < sched_interact) {
+ pri = PRI_MIN_INTERACT;
+ pri += ((PRI_MAX_INTERACT - PRI_MIN_INTERACT + 1) /
+ sched_interact) * score;
+ KASSERT(pri >= PRI_MIN_INTERACT && pri <= PRI_MAX_INTERACT,
+ ("sched_priority: invalid interactive priority %d score %d",
+ pri, score));
+ } else {
+ pri = SCHED_PRI_MIN;
+ if (td->td_sched->ts_ticks)
+ pri += min(SCHED_PRI_TICKS(td->td_sched),
+ SCHED_PRI_RANGE);
+ pri += SCHED_PRI_NICE(td->td_proc->p_nice);
+ KASSERT(pri >= PRI_MIN_BATCH && pri <= PRI_MAX_BATCH,
+ ("sched_priority: invalid priority %d: nice %d, "
+ "ticks %d ftick %d ltick %d tick pri %d",
+ pri, td->td_proc->p_nice, td->td_sched->ts_ticks,
+ td->td_sched->ts_ftick, td->td_sched->ts_ltick,
+ SCHED_PRI_TICKS(td->td_sched)));
+ }
+ sched_user_prio(td, pri);
+
+ return;
+}
+
+/*
+ * This routine enforces a maximum limit on the amount of scheduling history
+ * kept. It is called after either the slptime or runtime is adjusted. This
+ * function is ugly due to integer math.
+ */
+static void
+sched_interact_update(struct thread *td)
+{
+ struct td_sched *ts;
+ u_int sum;
+
+ ts = td->td_sched;
+ sum = ts->ts_runtime + ts->ts_slptime;
+ if (sum < SCHED_SLP_RUN_MAX)
+ return;
+ /*
+ * This only happens from two places:
+ * 1) We have added an unusual amount of run time from fork_exit.
+ * 2) We have added an unusual amount of sleep time from sched_sleep().
+ */
+ if (sum > SCHED_SLP_RUN_MAX * 2) {
+ if (ts->ts_runtime > ts->ts_slptime) {
+ ts->ts_runtime = SCHED_SLP_RUN_MAX;
+ ts->ts_slptime = 1;
+ } else {
+ ts->ts_slptime = SCHED_SLP_RUN_MAX;
+ ts->ts_runtime = 1;
+ }
+ return;
+ }
+ /*
+ * If we have exceeded by more than 1/5th then the algorithm below
+ * will not bring us back into range. Dividing by two here forces
+ * us into the range of [4/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX]
+ */
+ if (sum > (SCHED_SLP_RUN_MAX / 5) * 6) {
+ ts->ts_runtime /= 2;
+ ts->ts_slptime /= 2;
+ return;
+ }
+ ts->ts_runtime = (ts->ts_runtime / 5) * 4;
+ ts->ts_slptime = (ts->ts_slptime / 5) * 4;
+}
+
+/*
+ * Scale back the interactivity history when a child thread is created. The
+ * history is inherited from the parent but the thread may behave totally
+ * differently. For example, a shell spawning a compiler process. We want
+ * to learn that the compiler is behaving badly very quickly.
+ */
+static void
+sched_interact_fork(struct thread *td)
+{
+ int ratio;
+ int sum;
+
+ sum = td->td_sched->ts_runtime + td->td_sched->ts_slptime;
+ if (sum > SCHED_SLP_RUN_FORK) {
+ ratio = sum / SCHED_SLP_RUN_FORK;
+ td->td_sched->ts_runtime /= ratio;
+ td->td_sched->ts_slptime /= ratio;
+ }
+}
+
+/*
+ * Called from proc0_init() to setup the scheduler fields.
+ */
+void
+schedinit(void)
+{
+
+ /*
+ * Set up the scheduler specific parts of proc0.
+ */
+ proc0.p_sched = NULL; /* XXX */
+ thread0.td_sched = &td_sched0;
+ td_sched0.ts_ltick = ticks;
+ td_sched0.ts_ftick = ticks;
+ td_sched0.ts_slice = 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 stathz ticks.
+ */
+int
+sched_rr_interval(void)
+{
+
+ /* Convert sched_slice from stathz to hz. */
+ return (imax(1, (sched_slice * hz + realstathz / 2) / realstathz));
+}
+
+/*
+ * Update the percent cpu tracking information when it is requested or
+ * the total history exceeds the maximum. We keep a sliding history of
+ * tick counts that slowly decays. This is less precise than the 4BSD
+ * mechanism since it happens with less regular and frequent events.
+ */
+static void
+sched_pctcpu_update(struct td_sched *ts, int run)
+{
+ int t = ticks;
+
+ if (t - ts->ts_ltick >= SCHED_TICK_TARG) {
+ ts->ts_ticks = 0;
+ ts->ts_ftick = t - SCHED_TICK_TARG;
+ } else if (t - ts->ts_ftick >= SCHED_TICK_MAX) {
+ ts->ts_ticks = (ts->ts_ticks / (ts->ts_ltick - ts->ts_ftick)) *
+ (ts->ts_ltick - (t - SCHED_TICK_TARG));
+ ts->ts_ftick = t - SCHED_TICK_TARG;
+ }
+ if (run)
+ ts->ts_ticks += (t - ts->ts_ltick) << SCHED_TICK_SHIFT;
+ ts->ts_ltick = t;
+}
+
+/*
+ * Adjust the priority of a thread. Move it to the appropriate run-queue
+ * if necessary. This is the back-end for several priority related
+ * functions.
+ */
+static void
+sched_thread_priority(struct thread *td, u_char prio)
+{
+ struct td_sched *ts;
+ struct tdq *tdq;
+ int oldpri;
+
+ KTR_POINT3(KTR_SCHED, "thread", sched_tdname(td), "prio",
+ "prio:%d", td->td_priority, "new prio:%d", prio,
+ KTR_ATTR_LINKED, sched_tdname(curthread));
+ SDT_PROBE3(sched, , , change_pri, td, td->td_proc, prio);
+ if (td != curthread && prio < td->td_priority) {
+ KTR_POINT3(KTR_SCHED, "thread", sched_tdname(curthread),
+ "lend prio", "prio:%d", td->td_priority, "new prio:%d",
+ prio, KTR_ATTR_LINKED, sched_tdname(td));
+ SDT_PROBE4(sched, , , lend_pri, td, td->td_proc, prio,
+ curthread);
+ }
+ ts = td->td_sched;
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ if (td->td_priority == prio)
+ return;
+ /*
+ * If the priority has been elevated due to priority
+ * propagation, we may have to move ourselves to a new
+ * queue. This could be optimized to not re-add in some
+ * cases.
+ */
+ if (TD_ON_RUNQ(td) && prio < td->td_priority) {
+ sched_rem(td);
+ td->td_priority = prio;
+ sched_add(td, SRQ_BORROWING);
+ return;
+ }
+ /*
+ * If the thread is currently running we may have to adjust the lowpri
+ * information so other cpus are aware of our current priority.
+ */
+ if (TD_IS_RUNNING(td)) {
+ tdq = TDQ_CPU(ts->ts_cpu);
+ oldpri = td->td_priority;
+ td->td_priority = prio;
+ if (prio < tdq->tdq_lowpri)
+ tdq->tdq_lowpri = prio;
+ else if (tdq->tdq_lowpri == oldpri)
+ tdq_setlowpri(tdq, td);
+ return;
+ }
+ 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_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);
+}
+
+/*
+ * Standard entry for setting the priority to an absolute value.
+ */
+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_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);
+}
+
+/*
+ * Set the base user priority, does not effect current running priority.
+ */
+void
+sched_user_prio(struct thread *td, u_char prio)
+{
+
+ td->td_base_user_pri = prio;
+ if (td->td_lend_user_pri <= prio)
+ return;
+ td->td_user_pri = prio;
+}
+
+void
+sched_lend_user_prio(struct thread *td, u_char prio)
+{
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ td->td_lend_user_pri = prio;
+ td->td_user_pri = min(prio, td->td_base_user_pri);
+ if (td->td_priority > td->td_user_pri)
+ sched_prio(td, td->td_user_pri);
+ else if (td->td_priority != td->td_user_pri)
+ td->td_flags |= TDF_NEEDRESCHED;
+}
+
+/*
+ * Handle migration from sched_switch(). This happens only for
+ * cpu binding.
+ */
+static struct mtx *
+sched_switch_migrate(struct tdq *tdq, struct thread *td, int flags)
+{
+ struct tdq *tdn;
+
+ tdn = TDQ_CPU(td->td_sched->ts_cpu);
+#ifdef SMP
+ tdq_load_rem(tdq, td);
+ /*
+ * Do the lock dance required to avoid LOR. We grab an extra
+ * spinlock nesting to prevent preemption while we're
+ * not holding either run-queue lock.
+ */
+ spinlock_enter();
+ thread_lock_block(td); /* This releases the lock on tdq. */
+
+ /*
+ * Acquire both run-queue locks before placing the thread on the new
+ * run-queue to avoid deadlocks created by placing a thread with a
+ * blocked lock on the run-queue of a remote processor. The deadlock
+ * occurs when a third processor attempts to lock the two queues in
+ * question while the target processor is spinning with its own
+ * run-queue lock held while waiting for the blocked lock to clear.
+ */
+ tdq_lock_pair(tdn, tdq);
+ tdq_add(tdn, td, flags);
+ tdq_notify(tdn, td);
+ TDQ_UNLOCK(tdn);
+ spinlock_exit();
+#endif
+ return (TDQ_LOCKPTR(tdn));
+}
+
+/*
+ * Variadic version of thread_lock_unblock() that does not assume td_lock
+ * is blocked.
+ */
+static inline void
+thread_unblock_switch(struct thread *td, struct mtx *mtx)
+{
+ atomic_store_rel_ptr((volatile uintptr_t *)&td->td_lock,
+ (uintptr_t)mtx);
+}
+
+/*
+ * Switch threads. This function has to handle threads coming in while
+ * blocked for some reason, running, or idle. It also must deal with
+ * migrating a thread from one queue to another as running threads may
+ * be assigned elsewhere via binding.
+ */
+void
+sched_switch(struct thread *td, struct thread *newtd, int flags)
+{
+ struct tdq *tdq;
+ struct td_sched *ts;
+ struct mtx *mtx;
+ int srqflag;
+ int cpuid, preempted;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ KASSERT(newtd == NULL, ("sched_switch: Unsupported newtd argument"));
+
+ cpuid = PCPU_GET(cpuid);
+ tdq = TDQ_CPU(cpuid);
+ ts = td->td_sched;
+ mtx = td->td_lock;
+ sched_pctcpu_update(ts, 1);
+ ts->ts_rltick = ticks;
+ td->td_lastcpu = td->td_oncpu;
+ td->td_oncpu = NOCPU;
+ preempted = !(td->td_flags & TDF_SLICEEND);
+ td->td_flags &= ~(TDF_NEEDRESCHED | TDF_SLICEEND);
+ td->td_owepreempt = 0;
+ if (!TD_IS_IDLETHREAD(td))
+ tdq->tdq_switchcnt++;
+ /*
+ * The lock pointer in an idle thread should never change. Reset it
+ * to CAN_RUN as well.
+ */
+ if (TD_IS_IDLETHREAD(td)) {
+ MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
+ TD_SET_CAN_RUN(td);
+ } else if (TD_IS_RUNNING(td)) {
+ MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
+ srqflag = preempted ?
+ SRQ_OURSELF|SRQ_YIELDING|SRQ_PREEMPTED :
+ SRQ_OURSELF|SRQ_YIELDING;
+#ifdef SMP
+ if (THREAD_CAN_MIGRATE(td) && !THREAD_CAN_SCHED(td, ts->ts_cpu))
+ ts->ts_cpu = sched_pickcpu(td, 0);
+#endif
+ if (ts->ts_cpu == cpuid)
+ tdq_runq_add(tdq, td, srqflag);
+ else {
+ KASSERT(THREAD_CAN_MIGRATE(td) ||
+ (ts->ts_flags & TSF_BOUND) != 0,
+ ("Thread %p shouldn't migrate", td));
+ mtx = sched_switch_migrate(tdq, td, srqflag);
+ }
+ } else {
+ /* This thread must be going to sleep. */
+ TDQ_LOCK(tdq);
+ mtx = thread_lock_block(td);
+ tdq_load_rem(tdq, td);
+ }
+ /*
+ * We enter here with the thread blocked and assigned to the
+ * appropriate cpu run-queue or sleep-queue and with the current
+ * thread-queue locked.
+ */
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
+ newtd = choosethread();
+ /*
+ * Call the MD code to switch contexts if necessary.
+ */
+ if (td != newtd) {
+#ifdef HWPMC_HOOKS
+ if (PMC_PROC_IS_USING_PMCS(td->td_proc))
+ PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_OUT);
+#endif
+ SDT_PROBE2(sched, , , off_cpu, td, td->td_proc);
+ lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object);
+ TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd;
+ sched_pctcpu_update(newtd->td_sched, 0);
+
+#ifdef KDTRACE_HOOKS
+ /*
+ * If DTrace has set the active vtime enum to anything
+ * other than INACTIVE (0), then it should have set the
+ * function to call.
+ */
+ if (dtrace_vtime_active)
+ (*dtrace_vtime_switch_func)(newtd);
+#endif
+
+ cpu_switch(td, newtd, mtx);
+ /*
+ * We may return from cpu_switch on a different cpu. However,
+ * we always return with td_lock pointing to the current cpu's
+ * run queue lock.
+ */
+ cpuid = PCPU_GET(cpuid);
+ tdq = TDQ_CPU(cpuid);
+ lock_profile_obtain_lock_success(
+ &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
+
+ SDT_PROBE0(sched, , , on_cpu);
+#ifdef HWPMC_HOOKS
+ if (PMC_PROC_IS_USING_PMCS(td->td_proc))
+ PMC_SWITCH_CONTEXT(td, PMC_FN_CSW_IN);
+#endif
+ } else {
+ thread_unblock_switch(td, mtx);
+ SDT_PROBE0(sched, , , remain_cpu);
+ }
+ /*
+ * Assert that all went well and return.
+ */
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED|MA_NOTRECURSED);
+ MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
+ td->td_oncpu = cpuid;
+}
+
+/*
+ * Adjust thread priorities as a result of a nice request.
+ */
+void
+sched_nice(struct proc *p, int nice)
+{
+ struct thread *td;
+
+ PROC_LOCK_ASSERT(p, MA_OWNED);
+
+ p->p_nice = nice;
+ FOREACH_THREAD_IN_PROC(p, td) {
+ thread_lock(td);
+ sched_priority(td);
+ sched_prio(td, td->td_base_user_pri);
+ thread_unlock(td);
+ }
+}
+
+/*
+ * Record the sleep time for the interactivity scorer.
+ */
+void
+sched_sleep(struct thread *td, int prio)
+{
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+
+ td->td_slptick = ticks;
+ if (TD_IS_SUSPENDED(td) || prio >= PSOCK)
+ td->td_flags |= TDF_CANSWAP;
+ if (PRI_BASE(td->td_pri_class) != PRI_TIMESHARE)
+ return;
+ if (static_boost == 1 && prio)
+ sched_prio(td, prio);
+ else if (static_boost && td->td_priority > static_boost)
+ sched_prio(td, static_boost);
+}
+
+/*
+ * Schedule a thread to resume execution and record how long it voluntarily
+ * slept. We also update the pctcpu, interactivity, and priority.
+ */
+void
+sched_wakeup(struct thread *td)
+{
+ struct td_sched *ts;
+ int slptick;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ ts = td->td_sched;
+ td->td_flags &= ~TDF_CANSWAP;
+ /*
+ * If we slept for more than a tick update our interactivity and
+ * priority.
+ */
+ slptick = td->td_slptick;
+ td->td_slptick = 0;
+ if (slptick && slptick != ticks) {
+ ts->ts_slptime += (ticks - slptick) << SCHED_TICK_SHIFT;
+ sched_interact_update(td);
+ sched_pctcpu_update(ts, 0);
+ }
+ /*
+ * Reset the slice value since we slept and advanced the round-robin.
+ */
+ ts->ts_slice = 0;
+ sched_add(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 *child)
+{
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ sched_pctcpu_update(td->td_sched, 1);
+ sched_fork_thread(td, child);
+ /*
+ * Penalize the parent and child for forking.
+ */
+ sched_interact_fork(child);
+ sched_priority(child);
+ td->td_sched->ts_runtime += tickincr;
+ sched_interact_update(td);
+ sched_priority(td);
+}
+
+/*
+ * Fork a new thread, may be within the same process.
+ */
+void
+sched_fork_thread(struct thread *td, struct thread *child)
+{
+ struct td_sched *ts;
+ struct td_sched *ts2;
+ struct tdq *tdq;
+
+ tdq = TDQ_SELF();
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ /*
+ * Initialize child.
+ */
+ ts = td->td_sched;
+ ts2 = child->td_sched;
+ child->td_lock = TDQ_LOCKPTR(tdq);
+ child->td_cpuset = cpuset_ref(td->td_cpuset);
+ ts2->ts_cpu = ts->ts_cpu;
+ ts2->ts_flags = 0;
+ /*
+ * Grab our parents cpu estimation information.
+ */
+ ts2->ts_ticks = ts->ts_ticks;
+ ts2->ts_ltick = ts->ts_ltick;
+ ts2->ts_ftick = ts->ts_ftick;
+ /*
+ * Do not inherit any borrowed priority from the parent.
+ */
+ child->td_priority = child->td_base_pri;
+ /*
+ * And update interactivity score.
+ */
+ ts2->ts_slptime = ts->ts_slptime;
+ ts2->ts_runtime = ts->ts_runtime;
+ /* Attempt to quickly learn interactivity. */
+ ts2->ts_slice = tdq_slice(tdq) - sched_slice_min;
+#ifdef KTR
+ bzero(ts2->ts_name, sizeof(ts2->ts_name));
+#endif
+}
+
+/*
+ * Adjust the priority class of a thread.
+ */
+void
+sched_class(struct thread *td, int class)
+{
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ if (td->td_pri_class == class)
+ return;
+ td->td_pri_class = class;
+}
+
+/*
+ * Return some of the child's priority and interactivity to the parent.
+ */
+void
+sched_exit(struct proc *p, struct thread *child)
+{
+ struct thread *td;
+
+ KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "proc exit",
+ "prio:%d", child->td_priority);
+ PROC_LOCK_ASSERT(p, MA_OWNED);
+ td = FIRST_THREAD_IN_PROC(p);
+ sched_exit_thread(td, child);
+}
+
+/*
+ * Penalize another thread for the time spent on this one. This helps to
+ * worsen the priority and interactivity of processes which schedule batch
+ * jobs such as make. This has little effect on the make process itself but
+ * causes new processes spawned by it to receive worse scores immediately.
+ */
+void
+sched_exit_thread(struct thread *td, struct thread *child)
+{
+
+ KTR_STATE1(KTR_SCHED, "thread", sched_tdname(child), "thread exit",
+ "prio:%d", child->td_priority);
+ /*
+ * Give the child's runtime to the parent without returning the
+ * sleep time as a penalty to the parent. This causes shells that
+ * launch expensive things to mark their children as expensive.
+ */
+ thread_lock(td);
+ td->td_sched->ts_runtime += child->td_sched->ts_runtime;
+ sched_interact_update(td);
+ sched_priority(td);
+ thread_unlock(td);
+}
+
+void
+sched_preempt(struct thread *td)
+{
+ struct tdq *tdq;
+
+ SDT_PROBE2(sched, , , surrender, td, td->td_proc);
+
+ thread_lock(td);
+ tdq = TDQ_SELF();
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ tdq->tdq_ipipending = 0;
+ if (td->td_priority > tdq->tdq_lowpri) {
+ int flags;
+
+ flags = SW_INVOL | SW_PREEMPT;
+ if (td->td_critnest > 1)
+ td->td_owepreempt = 1;
+ else if (TD_IS_IDLETHREAD(td))
+ mi_switch(flags | SWT_REMOTEWAKEIDLE, NULL);
+ else
+ mi_switch(flags | SWT_REMOTEPREEMPT, NULL);
+ }
+ thread_unlock(td);
+}
+
+/*
+ * Fix priorities on return to user-space. Priorities may be elevated due
+ * to static priorities in msleep() or similar.
+ */
+void
+sched_userret(struct thread *td)
+{
+ /*
+ * 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"));
+ if (td->td_priority != td->td_user_pri) {
+ thread_lock(td);
+ td->td_priority = td->td_user_pri;
+ td->td_base_pri = td->td_user_pri;
+ tdq_setlowpri(TDQ_SELF(), td);
+ thread_unlock(td);
+ }
+}
+
+/*
+ * Handle a stathz tick. This is really only relevant for timeshare
+ * threads.
+ */
+void
+sched_clock(struct thread *td)
+{
+ struct tdq *tdq;
+ struct td_sched *ts;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ tdq = TDQ_SELF();
+#ifdef SMP
+ /*
+ * We run the long term load balancer infrequently on the first cpu.
+ */
+ if (balance_tdq == tdq) {
+ if (balance_ticks && --balance_ticks == 0)
+ sched_balance();
+ }
+#endif
+ /*
+ * Save the old switch count so we have a record of the last ticks
+ * activity. Initialize the new switch count based on our load.
+ * If there is some activity seed it to reflect that.
+ */
+ tdq->tdq_oldswitchcnt = tdq->tdq_switchcnt;
+ tdq->tdq_switchcnt = tdq->tdq_load;
+ /*
+ * Advance the insert index once for each tick to ensure that all
+ * threads get a chance to run.
+ */
+ if (tdq->tdq_idx == tdq->tdq_ridx) {
+ tdq->tdq_idx = (tdq->tdq_idx + 1) % RQ_NQS;
+ if (TAILQ_EMPTY(&tdq->tdq_timeshare.rq_queues[tdq->tdq_ridx]))
+ tdq->tdq_ridx = tdq->tdq_idx;
+ }
+ ts = td->td_sched;
+ sched_pctcpu_update(ts, 1);
+ if (td->td_pri_class & PRI_FIFO_BIT)
+ return;
+ if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) {
+ /*
+ * We used a tick; charge it to the thread so
+ * that we can compute our interactivity.
+ */
+ td->td_sched->ts_runtime += tickincr;
+ sched_interact_update(td);
+ sched_priority(td);
+ }
+
+ /*
+ * Force a context switch if the current thread has used up a full
+ * time slice (default is 100ms).
+ */
+ if (!TD_IS_IDLETHREAD(td) && ++ts->ts_slice >= tdq_slice(tdq)) {
+ ts->ts_slice = 0;
+ td->td_flags |= TDF_NEEDRESCHED | TDF_SLICEEND;
+ }
+}
+
+/*
+ * Called once per hz tick.
+ */
+void
+sched_tick(int cnt)
+{
+
+}
+
+/*
+ * Return whether the current CPU has runnable tasks. Used for in-kernel
+ * cooperative idle threads.
+ */
+int
+sched_runnable(void)
+{
+ struct tdq *tdq;
+ int load;
+
+ load = 1;
+
+ tdq = TDQ_SELF();
+ if ((curthread->td_flags & TDF_IDLETD) != 0) {
+ if (tdq->tdq_load > 0)
+ goto out;
+ } else
+ if (tdq->tdq_load - 1 > 0)
+ goto out;
+ load = 0;
+out:
+ return (load);
+}
+
+/*
+ * Choose the highest priority thread to run. The thread is removed from
+ * the run-queue while running however the load remains. For SMP we set
+ * the tdq in the global idle bitmask if it idles here.
+ */
+struct thread *
+sched_choose(void)
+{
+ struct thread *td;
+ struct tdq *tdq;
+
+ tdq = TDQ_SELF();
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ td = tdq_choose(tdq);
+ if (td) {
+ tdq_runq_rem(tdq, td);
+ tdq->tdq_lowpri = td->td_priority;
+ return (td);
+ }
+ tdq->tdq_lowpri = PRI_MAX_IDLE;
+ return (PCPU_GET(idlethread));
+}
+
+/*
+ * Set owepreempt if necessary. Preemption never happens directly in ULE,
+ * we always request it once we exit a critical section.
+ */
+static inline void
+sched_setpreempt(struct thread *td)
+{
+ struct thread *ctd;
+ int cpri;
+ int pri;
+
+ THREAD_LOCK_ASSERT(curthread, MA_OWNED);
+
+ ctd = curthread;
+ pri = td->td_priority;
+ cpri = ctd->td_priority;
+ if (pri < cpri)
+ ctd->td_flags |= TDF_NEEDRESCHED;
+ if (panicstr != NULL || pri >= cpri || cold || TD_IS_INHIBITED(ctd))
+ return;
+ if (!sched_shouldpreempt(pri, cpri, 0))
+ return;
+ ctd->td_owepreempt = 1;
+}
+
+/*
+ * Add a thread to a thread queue. Select the appropriate runq and add the
+ * thread to it. This is the internal function called when the tdq is
+ * predetermined.
+ */
+void
+tdq_add(struct tdq *tdq, struct thread *td, int flags)
+{
+
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ KASSERT((td->td_inhibitors == 0),
+ ("sched_add: trying to run inhibited thread"));
+ KASSERT((TD_CAN_RUN(td) || TD_IS_RUNNING(td)),
+ ("sched_add: bad thread state"));
+ KASSERT(td->td_flags & TDF_INMEM,
+ ("sched_add: thread swapped out"));
+
+ if (td->td_priority < tdq->tdq_lowpri)
+ tdq->tdq_lowpri = td->td_priority;
+ tdq_runq_add(tdq, td, flags);
+ tdq_load_add(tdq, td);
+}
+
+/*
+ * Select the target thread queue and add a thread to it. Request
+ * preemption or IPI a remote processor if required.
+ */
+void
+sched_add(struct thread *td, int flags)
+{
+ struct tdq *tdq;
+#ifdef SMP
+ int cpu;
+#endif
+
+ KTR_STATE2(KTR_SCHED, "thread", sched_tdname(td), "runq add",
+ "prio:%d", td->td_priority, KTR_ATTR_LINKED,
+ sched_tdname(curthread));
+ KTR_POINT1(KTR_SCHED, "thread", sched_tdname(curthread), "wokeup",
+ KTR_ATTR_LINKED, sched_tdname(td));
+ SDT_PROBE4(sched, , , enqueue, td, td->td_proc, NULL,
+ flags & SRQ_PREEMPTED);
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ /*
+ * Recalculate the priority before we select the target cpu or
+ * run-queue.
+ */
+ if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE)
+ sched_priority(td);
+#ifdef SMP
+ /*
+ * Pick the destination cpu and if it isn't ours transfer to the
+ * target cpu.
+ */
+ cpu = sched_pickcpu(td, flags);
+ tdq = sched_setcpu(td, cpu, flags);
+ tdq_add(tdq, td, flags);
+ if (cpu != PCPU_GET(cpuid)) {
+ tdq_notify(tdq, td);
+ return;
+ }
+#else
+ tdq = TDQ_SELF();
+ TDQ_LOCK(tdq);
+ /*
+ * Now that the thread is moving to the run-queue, set the lock
+ * to the scheduler's lock.
+ */
+ thread_lock_set(td, TDQ_LOCKPTR(tdq));
+ tdq_add(tdq, td, flags);
+#endif
+ if (!(flags & SRQ_YIELDING))
+ sched_setpreempt(td);
+}
+
+/*
+ * Remove a thread from a run-queue without running it. This is used
+ * when we're stealing a thread from a remote queue. Otherwise all threads
+ * exit by calling sched_exit_thread() and sched_throw() themselves.
+ */
+void
+sched_rem(struct thread *td)
+{
+ struct tdq *tdq;
+
+ KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "runq rem",
+ "prio:%d", td->td_priority);
+ SDT_PROBE3(sched, , , dequeue, td, td->td_proc, NULL);
+ tdq = TDQ_CPU(td->td_sched->ts_cpu);
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED);
+ MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
+ KASSERT(TD_ON_RUNQ(td),
+ ("sched_rem: thread not on run queue"));
+ tdq_runq_rem(tdq, td);
+ tdq_load_rem(tdq, td);
+ TD_SET_CAN_RUN(td);
+ if (td->td_priority == tdq->tdq_lowpri)
+ tdq_setlowpri(tdq, NULL);
+}
+
+/*
+ * Fetch cpu utilization information. Updates on demand.
+ */
+fixpt_t
+sched_pctcpu(struct thread *td)
+{
+ fixpt_t pctcpu;
+ struct td_sched *ts;
+
+ pctcpu = 0;
+ ts = td->td_sched;
+ if (ts == NULL)
+ return (0);
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ sched_pctcpu_update(ts, TD_IS_RUNNING(td));
+ if (ts->ts_ticks) {
+ int rtick;
+
+ /* How many rtick per second ? */
+ rtick = min(SCHED_TICK_HZ(ts) / SCHED_TICK_SECS, hz);
+ pctcpu = (FSCALE * ((FSCALE * rtick)/hz)) >> FSHIFT;
+ }
+
+ return (pctcpu);
+}
+
+/*
+ * Enforce affinity settings for a thread. Called after adjustments to
+ * cpumask.
+ */
+void
+sched_affinity(struct thread *td)
+{
+#ifdef SMP
+ struct td_sched *ts;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ ts = td->td_sched;
+ if (THREAD_CAN_SCHED(td, ts->ts_cpu))
+ return;
+ if (TD_ON_RUNQ(td)) {
+ sched_rem(td);
+ sched_add(td, SRQ_BORING);
+ return;
+ }
+ if (!TD_IS_RUNNING(td))
+ return;
+ /*
+ * Force a switch before returning to userspace. If the
+ * target thread is not running locally send an ipi to force
+ * the issue.
+ */
+ td->td_flags |= TDF_NEEDRESCHED;
+ if (td != curthread)
+ ipi_cpu(ts->ts_cpu, IPI_PREEMPT);
+#endif
+}
+
+/*
+ * Bind a thread to a target cpu.
+ */
+void
+sched_bind(struct thread *td, int cpu)
+{
+ struct td_sched *ts;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED|MA_NOTRECURSED);
+ KASSERT(td == curthread, ("sched_bind: can only bind curthread"));
+ ts = td->td_sched;
+ if (ts->ts_flags & TSF_BOUND)
+ sched_unbind(td);
+ KASSERT(THREAD_CAN_MIGRATE(td), ("%p must be migratable", td));
+ ts->ts_flags |= TSF_BOUND;
+ sched_pin();
+ if (PCPU_GET(cpuid) == cpu)
+ return;
+ ts->ts_cpu = cpu;
+ /* When we return from mi_switch we'll be on the correct cpu. */
+ mi_switch(SW_VOL, NULL);
+}
+
+/*
+ * Release a bound thread.
+ */
+void
+sched_unbind(struct thread *td)
+{
+ struct td_sched *ts;
+
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ KASSERT(td == curthread, ("sched_unbind: can only bind curthread"));
+ ts = td->td_sched;
+ if ((ts->ts_flags & TSF_BOUND) == 0)
+ return;
+ ts->ts_flags &= ~TSF_BOUND;
+ sched_unpin();
+}
+
+int
+sched_is_bound(struct thread *td)
+{
+ THREAD_LOCK_ASSERT(td, MA_OWNED);
+ return (td->td_sched->ts_flags & TSF_BOUND);
+}
+
+/*
+ * Basic yield call.
+ */
+void
+sched_relinquish(struct thread *td)
+{
+ thread_lock(td);
+ mi_switch(SW_VOL | SWT_RELINQUISH, NULL);
+ thread_unlock(td);
+}
+
+/*
+ * Return the total system load.
+ */
+int
+sched_load(void)
+{
+#ifdef SMP
+ int total;
+ int i;
+
+ total = 0;
+ CPU_FOREACH(i)
+ total += TDQ_CPU(i)->tdq_sysload;
+ return (total);
+#else
+ return (TDQ_SELF()->tdq_sysload);
+#endif
+}
+
+int
+sched_sizeof_proc(void)
+{
+ return (sizeof(struct proc));
+}
+
+int
+sched_sizeof_thread(void)
+{
+ return (sizeof(struct thread) + sizeof(struct td_sched));
+}
+
+#ifdef SMP
+#define TDQ_IDLESPIN(tdq) \
+ ((tdq)->tdq_cg != NULL && ((tdq)->tdq_cg->cg_flags & CG_FLAG_THREAD) == 0)
+#else
+#define TDQ_IDLESPIN(tdq) 1
+#endif
+
+/*
+ * The actual idle process.
+ */
+void
+sched_idletd(void *dummy)
+{
+ struct thread *td;
+ struct tdq *tdq;
+ int oldswitchcnt, switchcnt;
+ int i;
+
+ mtx_assert(&Giant, MA_NOTOWNED);
+ td = curthread;
+ tdq = TDQ_SELF();
+ THREAD_NO_SLEEPING();
+ oldswitchcnt = -1;
+ for (;;) {
+ if (tdq->tdq_load) {
+ thread_lock(td);
+ mi_switch(SW_VOL | SWT_IDLE, NULL);
+ thread_unlock(td);
+ }
+ switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
+#ifdef SMP
+ if (switchcnt != oldswitchcnt) {
+ oldswitchcnt = switchcnt;
+ if (tdq_idled(tdq) == 0)
+ continue;
+ }
+ switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
+#else
+ oldswitchcnt = switchcnt;
+#endif
+ /*
+ * If we're switching very frequently, spin while checking
+ * for load rather than entering a low power state that
+ * may require an IPI. However, don't do any busy
+ * loops while on SMT machines as this simply steals
+ * cycles from cores doing useful work.
+ */
+ if (TDQ_IDLESPIN(tdq) && switchcnt > sched_idlespinthresh) {
+ for (i = 0; i < sched_idlespins; i++) {
+ if (tdq->tdq_load)
+ break;
+ cpu_spinwait();
+ }
+ }
+
+ /* If there was context switch during spin, restart it. */
+ switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
+ if (tdq->tdq_load != 0 || switchcnt != oldswitchcnt)
+ continue;
+
+ /* Run main MD idle handler. */
+ tdq->tdq_cpu_idle = 1;
+ cpu_idle(switchcnt * 4 > sched_idlespinthresh);
+ tdq->tdq_cpu_idle = 0;
+
+ /*
+ * Account thread-less hardware interrupts and
+ * other wakeup reasons equal to context switches.
+ */
+ switchcnt = tdq->tdq_switchcnt + tdq->tdq_oldswitchcnt;
+ if (switchcnt != oldswitchcnt)
+ continue;
+ tdq->tdq_switchcnt++;
+ oldswitchcnt++;
+ }
+}
+
+/*
+ * A CPU is entering for the first time or a thread is exiting.
+ */
+void
+sched_throw(struct thread *td)
+{
+ struct thread *newtd;
+ struct tdq *tdq;
+
+ tdq = TDQ_SELF();
+ if (td == NULL) {
+ /* Correct spinlock nesting and acquire the correct lock. */
+ TDQ_LOCK(tdq);
+ spinlock_exit();
+ PCPU_SET(switchtime, cpu_ticks());
+ PCPU_SET(switchticks, ticks);
+ } else {
+ MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
+ tdq_load_rem(tdq, td);
+ lock_profile_release_lock(&TDQ_LOCKPTR(tdq)->lock_object);
+ }
+ KASSERT(curthread->td_md.md_spinlock_count == 1, ("invalid count"));
+ newtd = choosethread();
+ TDQ_LOCKPTR(tdq)->mtx_lock = (uintptr_t)newtd;
+ cpu_throw(td, newtd); /* doesn't return */
+}
+
+/*
+ * This is called from fork_exit(). Just acquire the correct locks and
+ * let fork do the rest of the work.
+ */
+void
+sched_fork_exit(struct thread *td)
+{
+ struct td_sched *ts;
+ struct tdq *tdq;
+ int cpuid;
+
+ /*
+ * Finish setting up thread glue so that it begins execution in a
+ * non-nested critical section with the scheduler lock held.
+ */
+ cpuid = PCPU_GET(cpuid);
+ tdq = TDQ_CPU(cpuid);
+ ts = td->td_sched;
+ if (TD_IS_IDLETHREAD(td))
+ td->td_lock = TDQ_LOCKPTR(tdq);
+ MPASS(td->td_lock == TDQ_LOCKPTR(tdq));
+ td->td_oncpu = cpuid;
+ TDQ_LOCK_ASSERT(tdq, MA_OWNED | MA_NOTRECURSED);
+ lock_profile_obtain_lock_success(
+ &TDQ_LOCKPTR(tdq)->lock_object, 0, 0, __FILE__, __LINE__);
+}
+
+/*
+ * Create on first use to catch odd startup conditons.
+ */
+char *
+sched_tdname(struct thread *td)
+{
+#ifdef KTR
+ struct td_sched *ts;
+
+ ts = td->td_sched;
+ if (ts->ts_name[0] == '\0')
+ snprintf(ts->ts_name, sizeof(ts->ts_name),
+ "%s tid %d", td->td_name, td->td_tid);
+ return (ts->ts_name);
+#else
+ return (td->td_name);
+#endif
+}
+
+#ifdef KTR
+void
+sched_clear_tdname(struct thread *td)
+{
+ struct td_sched *ts;
+
+ ts = td->td_sched;
+ ts->ts_name[0] = '\0';
+}
+#endif
+
+#ifdef SMP
+
+/*
+ * Build the CPU topology dump string. Is recursively called to collect
+ * the topology tree.
+ */
+static int
+sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, struct cpu_group *cg,
+ int indent)
+{
+ char cpusetbuf[CPUSETBUFSIZ];
+ int i, first;
+
+ sbuf_printf(sb, "%*s<group level=\"%d\" cache-level=\"%d\">\n", indent,
+ "", 1 + indent / 2, cg->cg_level);
+ sbuf_printf(sb, "%*s <cpu count=\"%d\" mask=\"%s\">", indent, "",
+ cg->cg_count, cpusetobj_strprint(cpusetbuf, &cg->cg_mask));
+ first = TRUE;
+ for (i = 0; i < MAXCPU; i++) {
+ if (CPU_ISSET(i, &cg->cg_mask)) {
+ if (!first)
+ sbuf_printf(sb, ", ");
+ else
+ first = FALSE;
+ sbuf_printf(sb, "%d", i);
+ }
+ }
+ sbuf_printf(sb, "</cpu>\n");
+
+ if (cg->cg_flags != 0) {
+ sbuf_printf(sb, "%*s <flags>", indent, "");
+ if ((cg->cg_flags & CG_FLAG_HTT) != 0)
+ sbuf_printf(sb, "<flag name=\"HTT\">HTT group</flag>");
+ if ((cg->cg_flags & CG_FLAG_THREAD) != 0)
+ sbuf_printf(sb, "<flag name=\"THREAD\">THREAD group</flag>");
+ if ((cg->cg_flags & CG_FLAG_SMT) != 0)
+ sbuf_printf(sb, "<flag name=\"SMT\">SMT group</flag>");
+ sbuf_printf(sb, "</flags>\n");
+ }
+
+ if (cg->cg_children > 0) {
+ sbuf_printf(sb, "%*s <children>\n", indent, "");
+ for (i = 0; i < cg->cg_children; i++)
+ sysctl_kern_sched_topology_spec_internal(sb,
+ &cg->cg_child[i], indent+2);
+ sbuf_printf(sb, "%*s </children>\n", indent, "");
+ }
+ sbuf_printf(sb, "%*s</group>\n", indent, "");
+ return (0);
+}
+
+/*
+ * Sysctl handler for retrieving topology dump. It's a wrapper for
+ * the recursive sysctl_kern_smp_topology_spec_internal().
+ */
+static int
+sysctl_kern_sched_topology_spec(SYSCTL_HANDLER_ARGS)
+{
+ struct sbuf *topo;
+ int err;
+
+ KASSERT(cpu_top != NULL, ("cpu_top isn't initialized"));
+
+ topo = sbuf_new(NULL, NULL, 500, SBUF_AUTOEXTEND);
+ if (topo == NULL)
+ return (ENOMEM);
+
+ sbuf_printf(topo, "<groups>\n");
+ err = sysctl_kern_sched_topology_spec_internal(topo, cpu_top, 1);
+ sbuf_printf(topo, "</groups>\n");
+
+ if (err == 0) {
+ sbuf_finish(topo);
+ err = SYSCTL_OUT(req, sbuf_data(topo), sbuf_len(topo));
+ }
+ sbuf_delete(topo);
+ return (err);
+}
+
+#endif
+
+static int
+sysctl_kern_quantum(SYSCTL_HANDLER_ARGS)
+{
+ int error, new_val, period;
+
+ period = 1000000 / realstathz;
+ new_val = period * sched_slice;
+ error = sysctl_handle_int(oidp, &new_val, 0, req);
+ if (error != 0 || req->newptr == NULL)
+ return (error);
+ if (new_val <= 0)
+ return (EINVAL);
+ sched_slice = imax(1, (new_val + period / 2) / period);
+ sched_slice_min = sched_slice / SCHED_SLICE_MIN_DIVISOR;
+ hogticks = imax(1, (2 * hz * sched_slice + realstathz / 2) /
+ realstathz);
+ return (0);
+}
+
+SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "Scheduler");
+SYSCTL_STRING(_kern_sched, OID_AUTO, name, CTLFLAG_RD, "ULE", 0,
+ "Scheduler name");
+SYSCTL_PROC(_kern_sched, OID_AUTO, quantum, CTLTYPE_INT | CTLFLAG_RW,
+ NULL, 0, sysctl_kern_quantum, "I",
+ "Quantum for timeshare threads in microseconds");
+SYSCTL_INT(_kern_sched, OID_AUTO, slice, CTLFLAG_RW, &sched_slice, 0,
+ "Quantum for timeshare threads in stathz ticks");
+SYSCTL_INT(_kern_sched, OID_AUTO, interact, CTLFLAG_RW, &sched_interact, 0,
+ "Interactivity score threshold");
+SYSCTL_INT(_kern_sched, OID_AUTO, preempt_thresh, CTLFLAG_RW,
+ &preempt_thresh, 0,
+ "Maximal (lowest) priority for preemption");
+SYSCTL_INT(_kern_sched, OID_AUTO, static_boost, CTLFLAG_RW, &static_boost, 0,
+ "Assign static kernel priorities to sleeping threads");
+SYSCTL_INT(_kern_sched, OID_AUTO, idlespins, CTLFLAG_RW, &sched_idlespins, 0,
+ "Number of times idle thread will spin waiting for new work");
+SYSCTL_INT(_kern_sched, OID_AUTO, idlespinthresh, CTLFLAG_RW,
+ &sched_idlespinthresh, 0,
+ "Threshold before we will permit idle thread spinning");
+#ifdef SMP
+SYSCTL_INT(_kern_sched, OID_AUTO, affinity, CTLFLAG_RW, &affinity, 0,
+ "Number of hz ticks to keep thread affinity for");
+SYSCTL_INT(_kern_sched, OID_AUTO, balance, CTLFLAG_RW, &rebalance, 0,
+ "Enables the long-term load balancer");
+SYSCTL_INT(_kern_sched, OID_AUTO, balance_interval, CTLFLAG_RW,
+ &balance_interval, 0,
+ "Average period in stathz ticks to run the long-term balancer");
+SYSCTL_INT(_kern_sched, OID_AUTO, steal_idle, CTLFLAG_RW, &steal_idle, 0,
+ "Attempts to steal work from other cores before idling");
+SYSCTL_INT(_kern_sched, OID_AUTO, steal_thresh, CTLFLAG_RW, &steal_thresh, 0,
+ "Minimum load on remote CPU before we'll steal");
+SYSCTL_PROC(_kern_sched, OID_AUTO, topology_spec, CTLTYPE_STRING |
+ CTLFLAG_RD, NULL, 0, sysctl_kern_sched_topology_spec, "A",
+ "XML dump of detected CPU topology");
+#endif
+
+/* ps compat. All cpu percentages from ULE are weighted. */
+static int ccpu = 0;
+SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
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