b003da7938
activation (i.e., applications are using libpthread). This is because SCHED_ULE sometimes puts P_SA processes into ksq_next unnecessarily. Which doesn't give fair amount of CPU time to processes which are using scheduler-activation-based threads when other (semi-)CPU-intensive, non-P_SA processes are running. Further work will no doubt be done by jeffr at a later date. Submitted by: Taku YAMAMOTO <taku@cent.saitama-u.ac.jp> Reviewed by: rwatson, freebsd-current@
1762 lines
44 KiB
C
1762 lines
44 KiB
C
/*-
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* Copyright (c) 2002-2003, Jeffrey Roberson <jeff@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/ktr.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/resource.h>
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#include <sys/resourcevar.h>
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#include <sys/sched.h>
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#include <sys/smp.h>
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#include <sys/sx.h>
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#include <sys/sysctl.h>
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#include <sys/sysproto.h>
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#include <sys/vmmeter.h>
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#ifdef DDB
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#include <ddb/ddb.h>
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#endif
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#ifdef KTRACE
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#include <sys/uio.h>
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#include <sys/ktrace.h>
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#endif
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#include <machine/cpu.h>
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#include <machine/smp.h>
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#define KTR_ULE KTR_NFS
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/* decay 95% of `p_pctcpu' in 60 seconds; see CCPU_SHIFT before changing */
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/* XXX This is bogus compatability crap for ps */
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static fixpt_t ccpu = 0.95122942450071400909 * FSCALE; /* exp(-1/20) */
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SYSCTL_INT(_kern, OID_AUTO, ccpu, CTLFLAG_RD, &ccpu, 0, "");
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static void sched_setup(void *dummy);
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SYSINIT(sched_setup, SI_SUB_RUN_QUEUE, SI_ORDER_FIRST, sched_setup, NULL)
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static SYSCTL_NODE(_kern, OID_AUTO, sched, CTLFLAG_RW, 0, "SCHED");
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static int slice_min = 1;
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SYSCTL_INT(_kern_sched, OID_AUTO, slice_min, CTLFLAG_RW, &slice_min, 0, "");
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static int slice_max = 10;
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SYSCTL_INT(_kern_sched, OID_AUTO, slice_max, CTLFLAG_RW, &slice_max, 0, "");
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int realstathz;
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int tickincr = 1;
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#ifdef SMP
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/* Callouts to handle load balancing SMP systems. */
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static struct callout kseq_lb_callout;
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static struct callout kseq_group_callout;
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#endif
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/*
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* These datastructures are allocated within their parent datastructure but
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* are scheduler specific.
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*/
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struct ke_sched {
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int ske_slice;
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struct runq *ske_runq;
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/* The following variables are only used for pctcpu calculation */
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int ske_ltick; /* Last tick that we were running on */
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int ske_ftick; /* First tick that we were running on */
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int ske_ticks; /* Tick count */
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/* CPU that we have affinity for. */
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u_char ske_cpu;
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};
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#define ke_slice ke_sched->ske_slice
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#define ke_runq ke_sched->ske_runq
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#define ke_ltick ke_sched->ske_ltick
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#define ke_ftick ke_sched->ske_ftick
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#define ke_ticks ke_sched->ske_ticks
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#define ke_cpu ke_sched->ske_cpu
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#define ke_assign ke_procq.tqe_next
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#define KEF_ASSIGNED KEF_SCHED0 /* KSE is being migrated. */
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#define KEF_BOUND KEF_SCHED1 /* KSE can not migrate. */
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struct kg_sched {
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int skg_slptime; /* Number of ticks we vol. slept */
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int skg_runtime; /* Number of ticks we were running */
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};
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#define kg_slptime kg_sched->skg_slptime
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#define kg_runtime kg_sched->skg_runtime
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struct td_sched {
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int std_slptime;
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};
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#define td_slptime td_sched->std_slptime
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struct td_sched td_sched;
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struct ke_sched ke_sched;
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struct kg_sched kg_sched;
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struct ke_sched *kse0_sched = &ke_sched;
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struct kg_sched *ksegrp0_sched = &kg_sched;
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struct p_sched *proc0_sched = NULL;
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struct td_sched *thread0_sched = &td_sched;
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/*
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* The priority is primarily determined by the interactivity score. Thus, we
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* give lower(better) priorities to kse groups that use less CPU. The nice
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* value is then directly added to this to allow nice to have some effect
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* on latency.
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*
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* PRI_RANGE: Total priority range for timeshare threads.
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* PRI_NRESV: Number of nice values.
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* PRI_BASE: The start of the dynamic range.
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*/
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#define SCHED_PRI_RANGE (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1)
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#define SCHED_PRI_NRESV ((PRIO_MAX - PRIO_MIN) + 1)
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#define SCHED_PRI_NHALF (SCHED_PRI_NRESV / 2)
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#define SCHED_PRI_BASE (PRI_MIN_TIMESHARE)
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#define SCHED_PRI_INTERACT(score) \
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((score) * SCHED_PRI_RANGE / SCHED_INTERACT_MAX)
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/*
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* These determine the interactivity of a process.
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*
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* SLP_RUN_MAX: Maximum amount of sleep time + run time we'll accumulate
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* before throttling back.
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* SLP_RUN_FORK: Maximum slp+run time to inherit at fork time.
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* INTERACT_MAX: Maximum interactivity value. Smaller is better.
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* INTERACT_THRESH: Threshhold for placement on the current runq.
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*/
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#define SCHED_SLP_RUN_MAX ((hz * 5) << 10)
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#define SCHED_SLP_RUN_FORK ((hz / 2) << 10)
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#define SCHED_INTERACT_MAX (100)
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#define SCHED_INTERACT_HALF (SCHED_INTERACT_MAX / 2)
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#define SCHED_INTERACT_THRESH (30)
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/*
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* These parameters and macros determine the size of the time slice that is
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* granted to each thread.
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*
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* SLICE_MIN: Minimum time slice granted, in units of ticks.
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* SLICE_MAX: Maximum time slice granted.
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* SLICE_RANGE: Range of available time slices scaled by hz.
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* SLICE_SCALE: The number slices granted per val in the range of [0, max].
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* SLICE_NICE: Determine the amount of slice granted to a scaled nice.
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* SLICE_NTHRESH: The nice cutoff point for slice assignment.
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*/
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#define SCHED_SLICE_MIN (slice_min)
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#define SCHED_SLICE_MAX (slice_max)
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#define SCHED_SLICE_INTERACTIVE (slice_max)
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#define SCHED_SLICE_NTHRESH (SCHED_PRI_NHALF - 1)
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#define SCHED_SLICE_RANGE (SCHED_SLICE_MAX - SCHED_SLICE_MIN + 1)
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#define SCHED_SLICE_SCALE(val, max) (((val) * SCHED_SLICE_RANGE) / (max))
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#define SCHED_SLICE_NICE(nice) \
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(SCHED_SLICE_MAX - SCHED_SLICE_SCALE((nice), SCHED_SLICE_NTHRESH))
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/*
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* This macro determines whether or not the kse belongs on the current or
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* next run queue.
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*/
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#define SCHED_INTERACTIVE(kg) \
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(sched_interact_score(kg) < SCHED_INTERACT_THRESH)
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#define SCHED_CURR(kg, ke) \
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(ke->ke_thread->td_priority < kg->kg_user_pri || \
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SCHED_INTERACTIVE(kg))
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/*
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* Cpu percentage computation macros and defines.
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*
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* SCHED_CPU_TIME: Number of seconds to average the cpu usage across.
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* SCHED_CPU_TICKS: Number of hz ticks to average the cpu usage across.
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*/
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#define SCHED_CPU_TIME 10
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#define SCHED_CPU_TICKS (hz * SCHED_CPU_TIME)
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/*
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* kseq - per processor runqs and statistics.
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*/
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struct kseq {
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struct runq ksq_idle; /* Queue of IDLE threads. */
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struct runq ksq_timeshare[2]; /* Run queues for !IDLE. */
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struct runq *ksq_next; /* Next timeshare queue. */
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struct runq *ksq_curr; /* Current queue. */
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int ksq_load_timeshare; /* Load for timeshare. */
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int ksq_load; /* Aggregate load. */
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short ksq_nice[SCHED_PRI_NRESV]; /* KSEs in each nice bin. */
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short ksq_nicemin; /* Least nice. */
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#ifdef SMP
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int ksq_transferable;
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LIST_ENTRY(kseq) ksq_siblings; /* Next in kseq group. */
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struct kseq_group *ksq_group; /* Our processor group. */
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volatile struct kse *ksq_assigned; /* assigned by another CPU. */
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#else
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int ksq_sysload; /* For loadavg, !ITHD load. */
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#endif
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};
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#ifdef SMP
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/*
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* kseq groups are groups of processors which can cheaply share threads. When
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* one processor in the group goes idle it will check the runqs of the other
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* processors in its group prior to halting and waiting for an interrupt.
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* These groups are suitable for SMT (Symetric Multi-Threading) and not NUMA.
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* In a numa environment we'd want an idle bitmap per group and a two tiered
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* load balancer.
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*/
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struct kseq_group {
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int ksg_cpus; /* Count of CPUs in this kseq group. */
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int ksg_cpumask; /* Mask of cpus in this group. */
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int ksg_idlemask; /* Idle cpus in this group. */
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int ksg_mask; /* Bit mask for first cpu. */
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int ksg_load; /* Total load of this group. */
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int ksg_transferable; /* Transferable load of this group. */
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LIST_HEAD(, kseq) ksg_members; /* Linked list of all members. */
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};
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#endif
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/*
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* One kse queue per processor.
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*/
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#ifdef SMP
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static int kseq_idle;
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static int ksg_maxid;
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static struct kseq kseq_cpu[MAXCPU];
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static struct kseq_group kseq_groups[MAXCPU];
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#define KSEQ_SELF() (&kseq_cpu[PCPU_GET(cpuid)])
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#define KSEQ_CPU(x) (&kseq_cpu[(x)])
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#define KSEQ_ID(x) ((x) - kseq_cpu)
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#define KSEQ_GROUP(x) (&kseq_groups[(x)])
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#else /* !SMP */
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static struct kseq kseq_cpu;
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#define KSEQ_SELF() (&kseq_cpu)
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#define KSEQ_CPU(x) (&kseq_cpu)
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#endif
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static void sched_slice(struct kse *ke);
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static void sched_priority(struct ksegrp *kg);
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static int sched_interact_score(struct ksegrp *kg);
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static void sched_interact_update(struct ksegrp *kg);
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static void sched_interact_fork(struct ksegrp *kg);
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static void sched_pctcpu_update(struct kse *ke);
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/* Operations on per processor queues */
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static struct kse * kseq_choose(struct kseq *kseq);
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static void kseq_setup(struct kseq *kseq);
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static void kseq_load_add(struct kseq *kseq, struct kse *ke);
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static void kseq_load_rem(struct kseq *kseq, struct kse *ke);
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static __inline void kseq_runq_add(struct kseq *kseq, struct kse *ke);
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static __inline void kseq_runq_rem(struct kseq *kseq, struct kse *ke);
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static void kseq_nice_add(struct kseq *kseq, int nice);
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static void kseq_nice_rem(struct kseq *kseq, int nice);
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void kseq_print(int cpu);
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#ifdef SMP
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static int kseq_transfer(struct kseq *ksq, struct kse *ke, int class);
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static struct kse *runq_steal(struct runq *rq);
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static void sched_balance(void *arg);
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static void sched_balance_group(struct kseq_group *ksg);
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static void sched_balance_pair(struct kseq *high, struct kseq *low);
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static void kseq_move(struct kseq *from, int cpu);
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static int kseq_idled(struct kseq *kseq);
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static void kseq_notify(struct kse *ke, int cpu);
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static void kseq_assign(struct kseq *);
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static struct kse *kseq_steal(struct kseq *kseq, int stealidle);
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/*
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* On P4 Xeons the round-robin interrupt delivery is broken. As a result of
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* this, we can't pin interrupts to the cpu that they were delivered to,
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* otherwise all ithreads only run on CPU 0.
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*/
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#ifdef __i386__
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#define KSE_CAN_MIGRATE(ke, class) \
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((ke)->ke_thread->td_pinned == 0 && ((ke)->ke_flags & KEF_BOUND) == 0)
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#else /* !__i386__ */
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#define KSE_CAN_MIGRATE(ke, class) \
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((class) != PRI_ITHD && (ke)->ke_thread->td_pinned == 0 && \
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((ke)->ke_flags & KEF_BOUND) == 0)
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#endif /* !__i386__ */
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#endif
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void
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kseq_print(int cpu)
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{
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struct kseq *kseq;
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int i;
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kseq = KSEQ_CPU(cpu);
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printf("kseq:\n");
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printf("\tload: %d\n", kseq->ksq_load);
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printf("\tload TIMESHARE: %d\n", kseq->ksq_load_timeshare);
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#ifdef SMP
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printf("\tload transferable: %d\n", kseq->ksq_transferable);
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#endif
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printf("\tnicemin:\t%d\n", kseq->ksq_nicemin);
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printf("\tnice counts:\n");
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for (i = 0; i < SCHED_PRI_NRESV; i++)
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if (kseq->ksq_nice[i])
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printf("\t\t%d = %d\n",
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i - SCHED_PRI_NHALF, kseq->ksq_nice[i]);
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}
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static __inline void
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kseq_runq_add(struct kseq *kseq, struct kse *ke)
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{
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#ifdef SMP
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if (KSE_CAN_MIGRATE(ke, PRI_BASE(ke->ke_ksegrp->kg_pri_class))) {
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kseq->ksq_transferable++;
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kseq->ksq_group->ksg_transferable++;
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}
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#endif
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runq_add(ke->ke_runq, ke);
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}
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|
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static __inline void
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kseq_runq_rem(struct kseq *kseq, struct kse *ke)
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|
{
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#ifdef SMP
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if (KSE_CAN_MIGRATE(ke, PRI_BASE(ke->ke_ksegrp->kg_pri_class))) {
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kseq->ksq_transferable--;
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kseq->ksq_group->ksg_transferable--;
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}
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#endif
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runq_remove(ke->ke_runq, ke);
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}
|
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|
|
static void
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kseq_load_add(struct kseq *kseq, struct kse *ke)
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|
{
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|
int class;
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mtx_assert(&sched_lock, MA_OWNED);
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class = PRI_BASE(ke->ke_ksegrp->kg_pri_class);
|
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if (class == PRI_TIMESHARE)
|
|
kseq->ksq_load_timeshare++;
|
|
kseq->ksq_load++;
|
|
if (class != PRI_ITHD)
|
|
#ifdef SMP
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|
kseq->ksq_group->ksg_load++;
|
|
#else
|
|
kseq->ksq_sysload++;
|
|
#endif
|
|
if (ke->ke_ksegrp->kg_pri_class == PRI_TIMESHARE)
|
|
CTR6(KTR_ULE,
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|
"Add kse %p to %p (slice: %d, pri: %d, nice: %d(%d))",
|
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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);
|
|
}
|
|
|
|
static void
|
|
kseq_load_rem(struct kseq *kseq, struct kse *ke)
|
|
{
|
|
int class;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
class = PRI_BASE(ke->ke_ksegrp->kg_pri_class);
|
|
if (class == PRI_TIMESHARE)
|
|
kseq->ksq_load_timeshare--;
|
|
if (class != PRI_ITHD)
|
|
#ifdef SMP
|
|
kseq->ksq_group->ksg_load--;
|
|
#else
|
|
kseq->ksq_sysload--;
|
|
#endif
|
|
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);
|
|
}
|
|
|
|
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_load_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_load_timeshare == 0)
|
|
return;
|
|
|
|
for (; n < SCHED_PRI_NRESV; n++)
|
|
if (kseq->ksq_nice[n]) {
|
|
kseq->ksq_nicemin = n - SCHED_PRI_NHALF;
|
|
return;
|
|
}
|
|
}
|
|
|
|
#ifdef SMP
|
|
/*
|
|
* sched_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.
|
|
*
|
|
*/
|
|
static void
|
|
sched_balance(void *arg)
|
|
{
|
|
struct kseq_group *high;
|
|
struct kseq_group *low;
|
|
struct kseq_group *ksg;
|
|
int timo;
|
|
int cnt;
|
|
int i;
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if (smp_started == 0)
|
|
goto out;
|
|
low = high = NULL;
|
|
i = random() % (ksg_maxid + 1);
|
|
for (cnt = 0; cnt <= ksg_maxid; cnt++) {
|
|
ksg = KSEQ_GROUP(i);
|
|
/*
|
|
* Find the CPU with the highest load that has some
|
|
* threads to transfer.
|
|
*/
|
|
if ((high == NULL || ksg->ksg_load > high->ksg_load)
|
|
&& ksg->ksg_transferable)
|
|
high = ksg;
|
|
if (low == NULL || ksg->ksg_load < low->ksg_load)
|
|
low = ksg;
|
|
if (++i > ksg_maxid)
|
|
i = 0;
|
|
}
|
|
if (low != NULL && high != NULL && high != low)
|
|
sched_balance_pair(LIST_FIRST(&high->ksg_members),
|
|
LIST_FIRST(&low->ksg_members));
|
|
out:
|
|
mtx_unlock_spin(&sched_lock);
|
|
timo = random() % (hz * 2);
|
|
callout_reset(&kseq_lb_callout, timo, sched_balance, NULL);
|
|
}
|
|
|
|
static void
|
|
sched_balance_groups(void *arg)
|
|
{
|
|
int timo;
|
|
int i;
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if (smp_started)
|
|
for (i = 0; i <= ksg_maxid; i++)
|
|
sched_balance_group(KSEQ_GROUP(i));
|
|
mtx_unlock_spin(&sched_lock);
|
|
timo = random() % (hz * 2);
|
|
callout_reset(&kseq_group_callout, timo, sched_balance_groups, NULL);
|
|
}
|
|
|
|
static void
|
|
sched_balance_group(struct kseq_group *ksg)
|
|
{
|
|
struct kseq *kseq;
|
|
struct kseq *high;
|
|
struct kseq *low;
|
|
int load;
|
|
|
|
if (ksg->ksg_transferable == 0)
|
|
return;
|
|
low = NULL;
|
|
high = NULL;
|
|
LIST_FOREACH(kseq, &ksg->ksg_members, ksq_siblings) {
|
|
load = kseq->ksq_load;
|
|
if (kseq == KSEQ_CPU(0))
|
|
load--;
|
|
if (high == NULL || load > high->ksq_load)
|
|
high = kseq;
|
|
if (low == NULL || load < low->ksq_load)
|
|
low = kseq;
|
|
}
|
|
if (high != NULL && low != NULL && high != low)
|
|
sched_balance_pair(high, low);
|
|
}
|
|
|
|
static void
|
|
sched_balance_pair(struct kseq *high, struct kseq *low)
|
|
{
|
|
int transferable;
|
|
int high_load;
|
|
int low_load;
|
|
int move;
|
|
int diff;
|
|
int i;
|
|
|
|
/*
|
|
* If we're transfering within a group we have to use this specific
|
|
* kseq's transferable count, otherwise we can steal from other members
|
|
* of the group.
|
|
*/
|
|
if (high->ksq_group == low->ksq_group) {
|
|
transferable = high->ksq_transferable;
|
|
high_load = high->ksq_load;
|
|
low_load = low->ksq_load;
|
|
/*
|
|
* XXX If we encounter cpu 0 we must remember to reduce it's
|
|
* load by 1 to reflect the swi that is running the callout.
|
|
* At some point we should really fix load balancing of the
|
|
* swi and then this wont matter.
|
|
*/
|
|
if (high == KSEQ_CPU(0))
|
|
high_load--;
|
|
if (low == KSEQ_CPU(0))
|
|
low_load--;
|
|
} else {
|
|
transferable = high->ksq_group->ksg_transferable;
|
|
high_load = high->ksq_group->ksg_load;
|
|
low_load = low->ksq_group->ksg_load;
|
|
}
|
|
if (transferable == 0)
|
|
return;
|
|
/*
|
|
* Determine what the imbalance is and then adjust that to how many
|
|
* kses we actually have to give up (transferable).
|
|
*/
|
|
diff = high_load - low_load;
|
|
move = diff / 2;
|
|
if (diff & 0x1)
|
|
move++;
|
|
move = min(move, transferable);
|
|
for (i = 0; i < move; i++)
|
|
kseq_move(high, KSEQ_ID(low));
|
|
return;
|
|
}
|
|
|
|
static void
|
|
kseq_move(struct kseq *from, int cpu)
|
|
{
|
|
struct kseq *kseq;
|
|
struct kseq *to;
|
|
struct kse *ke;
|
|
|
|
kseq = from;
|
|
to = KSEQ_CPU(cpu);
|
|
ke = kseq_steal(kseq, 1);
|
|
if (ke == NULL) {
|
|
struct kseq_group *ksg;
|
|
|
|
ksg = kseq->ksq_group;
|
|
LIST_FOREACH(kseq, &ksg->ksg_members, ksq_siblings) {
|
|
if (kseq == from || kseq->ksq_transferable == 0)
|
|
continue;
|
|
ke = kseq_steal(kseq, 1);
|
|
break;
|
|
}
|
|
if (ke == NULL)
|
|
panic("kseq_move: No KSEs available with a "
|
|
"transferable count of %d\n",
|
|
ksg->ksg_transferable);
|
|
}
|
|
if (kseq == to)
|
|
return;
|
|
ke->ke_state = KES_THREAD;
|
|
kseq_runq_rem(kseq, ke);
|
|
kseq_load_rem(kseq, ke);
|
|
kseq_notify(ke, cpu);
|
|
}
|
|
|
|
static int
|
|
kseq_idled(struct kseq *kseq)
|
|
{
|
|
struct kseq_group *ksg;
|
|
struct kseq *steal;
|
|
struct kse *ke;
|
|
|
|
ksg = kseq->ksq_group;
|
|
/*
|
|
* If we're in a cpu group, try and steal kses from another cpu in
|
|
* the group before idling.
|
|
*/
|
|
if (ksg->ksg_cpus > 1 && ksg->ksg_transferable) {
|
|
LIST_FOREACH(steal, &ksg->ksg_members, ksq_siblings) {
|
|
if (steal == kseq || steal->ksq_transferable == 0)
|
|
continue;
|
|
ke = kseq_steal(steal, 0);
|
|
if (ke == NULL)
|
|
continue;
|
|
ke->ke_state = KES_THREAD;
|
|
kseq_runq_rem(steal, ke);
|
|
kseq_load_rem(steal, ke);
|
|
ke->ke_cpu = PCPU_GET(cpuid);
|
|
sched_add(ke->ke_thread);
|
|
return (0);
|
|
}
|
|
}
|
|
/*
|
|
* We only set the idled bit when all of the cpus in the group are
|
|
* idle. Otherwise we could get into a situation where a KSE bounces
|
|
* back and forth between two idle cores on seperate physical CPUs.
|
|
*/
|
|
ksg->ksg_idlemask |= PCPU_GET(cpumask);
|
|
if (ksg->ksg_idlemask != ksg->ksg_cpumask)
|
|
return (1);
|
|
atomic_set_int(&kseq_idle, ksg->ksg_mask);
|
|
return (1);
|
|
}
|
|
|
|
static void
|
|
kseq_assign(struct kseq *kseq)
|
|
{
|
|
struct kse *nke;
|
|
struct kse *ke;
|
|
|
|
do {
|
|
(volatile struct kse *)ke = kseq->ksq_assigned;
|
|
} while(!atomic_cmpset_ptr(&kseq->ksq_assigned, ke, NULL));
|
|
for (; ke != NULL; ke = nke) {
|
|
nke = ke->ke_assign;
|
|
ke->ke_flags &= ~KEF_ASSIGNED;
|
|
sched_add(ke->ke_thread);
|
|
}
|
|
}
|
|
|
|
static void
|
|
kseq_notify(struct kse *ke, int cpu)
|
|
{
|
|
struct kseq *kseq;
|
|
struct thread *td;
|
|
struct pcpu *pcpu;
|
|
|
|
ke->ke_cpu = cpu;
|
|
ke->ke_flags |= KEF_ASSIGNED;
|
|
|
|
kseq = KSEQ_CPU(cpu);
|
|
|
|
/*
|
|
* Place a KSE on another cpu's queue and force a resched.
|
|
*/
|
|
do {
|
|
(volatile struct kse *)ke->ke_assign = kseq->ksq_assigned;
|
|
} while(!atomic_cmpset_ptr(&kseq->ksq_assigned, ke->ke_assign, ke));
|
|
pcpu = pcpu_find(cpu);
|
|
td = pcpu->pc_curthread;
|
|
if (ke->ke_thread->td_priority < td->td_priority ||
|
|
td == pcpu->pc_idlethread) {
|
|
td->td_flags |= TDF_NEEDRESCHED;
|
|
ipi_selected(1 << cpu, IPI_AST);
|
|
}
|
|
}
|
|
|
|
static struct kse *
|
|
runq_steal(struct runq *rq)
|
|
{
|
|
struct rqhead *rqh;
|
|
struct rqbits *rqb;
|
|
struct kse *ke;
|
|
int word;
|
|
int bit;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
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(ke, rqh, ke_procq) {
|
|
if (KSE_CAN_MIGRATE(ke,
|
|
PRI_BASE(ke->ke_ksegrp->kg_pri_class)))
|
|
return (ke);
|
|
}
|
|
}
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
static struct kse *
|
|
kseq_steal(struct kseq *kseq, int stealidle)
|
|
{
|
|
struct kse *ke;
|
|
|
|
/*
|
|
* Steal from next first to try to get a non-interactive task that
|
|
* may not have run for a while.
|
|
*/
|
|
if ((ke = runq_steal(kseq->ksq_next)) != NULL)
|
|
return (ke);
|
|
if ((ke = runq_steal(kseq->ksq_curr)) != NULL)
|
|
return (ke);
|
|
if (stealidle)
|
|
return (runq_steal(&kseq->ksq_idle));
|
|
return (NULL);
|
|
}
|
|
|
|
int
|
|
kseq_transfer(struct kseq *kseq, struct kse *ke, int class)
|
|
{
|
|
struct kseq_group *ksg;
|
|
int cpu;
|
|
|
|
if (smp_started == 0)
|
|
return (0);
|
|
cpu = 0;
|
|
ksg = kseq->ksq_group;
|
|
|
|
/*
|
|
* If there are any idle groups, give them our extra load. The
|
|
* threshold at which we start to reassign kses has a large impact
|
|
* on the overall performance of the system. Tuned too high and
|
|
* some CPUs may idle. Too low and there will be excess migration
|
|
* and context swiches.
|
|
*/
|
|
if (ksg->ksg_load > (ksg->ksg_cpus * 2) && kseq_idle) {
|
|
/*
|
|
* Multiple cpus could find this bit simultaneously
|
|
* but the race shouldn't be terrible.
|
|
*/
|
|
cpu = ffs(kseq_idle);
|
|
if (cpu)
|
|
atomic_clear_int(&kseq_idle, 1 << (cpu - 1));
|
|
}
|
|
/*
|
|
* If another cpu in this group has idled, assign a thread over
|
|
* to them after checking to see if there are idled groups.
|
|
*/
|
|
if (cpu == 0 && kseq->ksq_load > 1 && ksg->ksg_idlemask) {
|
|
cpu = ffs(ksg->ksg_idlemask);
|
|
if (cpu)
|
|
ksg->ksg_idlemask &= ~(1 << (cpu - 1));
|
|
}
|
|
/*
|
|
* Now that we've found an idle CPU, migrate the thread.
|
|
*/
|
|
if (cpu) {
|
|
cpu--;
|
|
ke->ke_runq = NULL;
|
|
kseq_notify(ke, cpu);
|
|
return (1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
#endif /* SMP */
|
|
|
|
/*
|
|
* Pick the highest priority task we have and return it.
|
|
*/
|
|
|
|
static struct kse *
|
|
kseq_choose(struct kseq *kseq)
|
|
{
|
|
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) {
|
|
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_load = 0;
|
|
kseq->ksq_load_timeshare = 0;
|
|
}
|
|
|
|
static void
|
|
sched_setup(void *dummy)
|
|
{
|
|
#ifdef SMP
|
|
int balance_groups;
|
|
int i;
|
|
#endif
|
|
|
|
slice_min = (hz/100); /* 10ms */
|
|
slice_max = (hz/7); /* ~140ms */
|
|
|
|
#ifdef SMP
|
|
balance_groups = 0;
|
|
/*
|
|
* Initialize the kseqs.
|
|
*/
|
|
for (i = 0; i < MAXCPU; i++) {
|
|
struct kseq *ksq;
|
|
|
|
ksq = &kseq_cpu[i];
|
|
ksq->ksq_assigned = NULL;
|
|
kseq_setup(&kseq_cpu[i]);
|
|
}
|
|
if (smp_topology == NULL) {
|
|
struct kseq_group *ksg;
|
|
struct kseq *ksq;
|
|
|
|
for (i = 0; i < MAXCPU; i++) {
|
|
ksq = &kseq_cpu[i];
|
|
ksg = &kseq_groups[i];
|
|
/*
|
|
* Setup a kse group with one member.
|
|
*/
|
|
ksq->ksq_transferable = 0;
|
|
ksq->ksq_group = ksg;
|
|
ksg->ksg_cpus = 1;
|
|
ksg->ksg_idlemask = 0;
|
|
ksg->ksg_cpumask = ksg->ksg_mask = 1 << i;
|
|
ksg->ksg_load = 0;
|
|
ksg->ksg_transferable = 0;
|
|
LIST_INIT(&ksg->ksg_members);
|
|
LIST_INSERT_HEAD(&ksg->ksg_members, ksq, ksq_siblings);
|
|
}
|
|
} else {
|
|
struct kseq_group *ksg;
|
|
struct cpu_group *cg;
|
|
int j;
|
|
|
|
for (i = 0; i < smp_topology->ct_count; i++) {
|
|
cg = &smp_topology->ct_group[i];
|
|
ksg = &kseq_groups[i];
|
|
/*
|
|
* Initialize the group.
|
|
*/
|
|
ksg->ksg_idlemask = 0;
|
|
ksg->ksg_load = 0;
|
|
ksg->ksg_transferable = 0;
|
|
ksg->ksg_cpus = cg->cg_count;
|
|
ksg->ksg_cpumask = cg->cg_mask;
|
|
LIST_INIT(&ksg->ksg_members);
|
|
/*
|
|
* Find all of the group members and add them.
|
|
*/
|
|
for (j = 0; j < MAXCPU; j++) {
|
|
if ((cg->cg_mask & (1 << j)) != 0) {
|
|
if (ksg->ksg_mask == 0)
|
|
ksg->ksg_mask = 1 << j;
|
|
kseq_cpu[j].ksq_transferable = 0;
|
|
kseq_cpu[j].ksq_group = ksg;
|
|
LIST_INSERT_HEAD(&ksg->ksg_members,
|
|
&kseq_cpu[j], ksq_siblings);
|
|
}
|
|
}
|
|
if (ksg->ksg_cpus > 1)
|
|
balance_groups = 1;
|
|
}
|
|
ksg_maxid = smp_topology->ct_count - 1;
|
|
}
|
|
callout_init(&kseq_lb_callout, CALLOUT_MPSAFE);
|
|
callout_init(&kseq_group_callout, CALLOUT_MPSAFE);
|
|
sched_balance(NULL);
|
|
/*
|
|
* Stagger the group and global load balancer so they do not
|
|
* interfere with each other.
|
|
*/
|
|
if (balance_groups)
|
|
callout_reset(&kseq_group_callout, hz / 2,
|
|
sched_balance_groups, NULL);
|
|
#else
|
|
kseq_setup(KSEQ_SELF());
|
|
#endif
|
|
mtx_lock_spin(&sched_lock);
|
|
kseq_load_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 the kse is outside of the window it will get no slice
|
|
* and will be reevaluated each time it is selected on the
|
|
* run queue. The exception to this is nice 0 ksegs when
|
|
* a nice -20 is running. They are always granted a minimum
|
|
* slice.
|
|
*/
|
|
if (!SCHED_INTERACTIVE(kg)) {
|
|
int nice;
|
|
|
|
nice = kg->kg_nice + (0 - kseq->ksq_nicemin);
|
|
if (kseq->ksq_load_timeshare == 0 ||
|
|
kg->kg_nice < kseq->ksq_nicemin)
|
|
ke->ke_slice = SCHED_SLICE_MAX;
|
|
else if (nice <= SCHED_SLICE_NTHRESH)
|
|
ke->ke_slice = SCHED_SLICE_NICE(nice);
|
|
else if (kg->kg_nice == 0)
|
|
ke->ke_slice = SCHED_SLICE_MIN;
|
|
else
|
|
ke->ke_slice = 0;
|
|
} else
|
|
ke->ke_slice = SCHED_SLICE_INTERACTIVE;
|
|
|
|
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_load_timeshare, SCHED_INTERACTIVE(kg));
|
|
|
|
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 routine will not operate correctly when slp or run times have been
|
|
* adjusted to more than double their maximum.
|
|
*/
|
|
static void
|
|
sched_interact_update(struct ksegrp *kg)
|
|
{
|
|
int sum;
|
|
|
|
sum = kg->kg_runtime + kg->kg_slptime;
|
|
if (sum < SCHED_SLP_RUN_MAX)
|
|
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 [3/5 * SCHED_INTERACT_MAX, SCHED_INTERACT_MAX]
|
|
*/
|
|
if (sum > (SCHED_INTERACT_MAX / 5) * 6) {
|
|
kg->kg_runtime /= 2;
|
|
kg->kg_slptime /= 2;
|
|
return;
|
|
}
|
|
kg->kg_runtime = (kg->kg_runtime / 5) * 4;
|
|
kg->kg_slptime = (kg->kg_slptime / 5) * 4;
|
|
}
|
|
|
|
static void
|
|
sched_interact_fork(struct ksegrp *kg)
|
|
{
|
|
int ratio;
|
|
int sum;
|
|
|
|
sum = kg->kg_runtime + kg->kg_slptime;
|
|
if (sum > SCHED_SLP_RUN_FORK) {
|
|
ratio = sum / SCHED_SLP_RUN_FORK;
|
|
kg->kg_runtime /= ratio;
|
|
kg->kg_slptime /= ratio;
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static void
|
|
sched_pctcpu_update(struct kse *ke)
|
|
{
|
|
/*
|
|
* Adjust counters and watermark for pctcpu calc.
|
|
*/
|
|
if (ke->ke_ltick > ticks - SCHED_CPU_TICKS) {
|
|
/*
|
|
* Shift the tick count out so that the divide doesn't
|
|
* round away our results.
|
|
*/
|
|
ke->ke_ticks <<= 10;
|
|
ke->ke_ticks = (ke->ke_ticks / (ticks - ke->ke_ftick)) *
|
|
SCHED_CPU_TICKS;
|
|
ke->ke_ticks >>= 10;
|
|
} else
|
|
ke->ke_ticks = 0;
|
|
ke->ke_ltick = ticks;
|
|
ke->ke_ftick = ke->ke_ltick - SCHED_CPU_TICKS;
|
|
}
|
|
|
|
void
|
|
sched_prio(struct thread *td, u_char prio)
|
|
{
|
|
struct kse *ke;
|
|
|
|
ke = td->td_kse;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (TD_ON_RUNQ(td)) {
|
|
/*
|
|
* If the priority has been elevated due to priority
|
|
* propagation, we may have to move ourselves to a new
|
|
* queue. We still call adjustrunqueue below in case kse
|
|
* needs to fix things up.
|
|
*/
|
|
if (prio < td->td_priority && ke &&
|
|
(ke->ke_flags & KEF_ASSIGNED) == 0 &&
|
|
ke->ke_runq != KSEQ_CPU(ke->ke_cpu)->ksq_curr) {
|
|
runq_remove(ke->ke_runq, ke);
|
|
ke->ke_runq = KSEQ_CPU(ke->ke_cpu)->ksq_curr;
|
|
runq_add(ke->ke_runq, ke);
|
|
}
|
|
adjustrunqueue(td, prio);
|
|
} else
|
|
td->td_priority = prio;
|
|
}
|
|
|
|
void
|
|
sched_switch(struct thread *td)
|
|
{
|
|
struct thread *newtd;
|
|
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 the KSE has been assigned it may be in the process of switching
|
|
* to the new cpu. This is the case in sched_bind().
|
|
*/
|
|
if ((ke->ke_flags & KEF_ASSIGNED) == 0) {
|
|
if (TD_IS_RUNNING(td)) {
|
|
kseq_load_rem(KSEQ_CPU(ke->ke_cpu), ke);
|
|
setrunqueue(td);
|
|
} else {
|
|
if (ke->ke_runq) {
|
|
kseq_load_rem(KSEQ_CPU(ke->ke_cpu), ke);
|
|
} else if ((td->td_flags & TDF_IDLETD) == 0)
|
|
backtrace();
|
|
/*
|
|
* 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);
|
|
}
|
|
}
|
|
newtd = choosethread();
|
|
if (td != newtd)
|
|
cpu_switch(td, newtd);
|
|
sched_lock.mtx_lock = (uintptr_t)td;
|
|
|
|
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)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
|
|
td->td_slptime = ticks;
|
|
td->td_base_pri = td->td_priority;
|
|
|
|
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) << 10;
|
|
if (hzticks >= SCHED_SLP_RUN_MAX) {
|
|
kg->kg_slptime = SCHED_SLP_RUN_MAX;
|
|
kg->kg_runtime = 1;
|
|
} else {
|
|
kg->kg_slptime += hzticks;
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
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);
|
|
|
|
child->kg_slptime = kg->kg_slptime;
|
|
child->kg_runtime = kg->kg_runtime;
|
|
child->kg_user_pri = kg->kg_user_pri;
|
|
child->kg_nice = kg->kg_nice;
|
|
sched_interact_fork(child);
|
|
kg->kg_runtime += tickincr << 10;
|
|
sched_interact_update(kg);
|
|
|
|
CTR6(KTR_ULE, "sched_fork_ksegrp: %d(%d, %d) - %d(%d, %d)",
|
|
kg->kg_proc->p_pid, kg->kg_slptime, kg->kg_runtime,
|
|
child->kg_proc->p_pid, child->kg_slptime, child->kg_runtime);
|
|
}
|
|
|
|
void
|
|
sched_fork_thread(struct thread *td, struct thread *child)
|
|
{
|
|
}
|
|
|
|
void
|
|
sched_class(struct ksegrp *kg, int class)
|
|
{
|
|
struct kseq *kseq;
|
|
struct kse *ke;
|
|
int nclass;
|
|
int oclass;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
if (kg->kg_pri_class == class)
|
|
return;
|
|
|
|
nclass = PRI_BASE(class);
|
|
oclass = PRI_BASE(kg->kg_pri_class);
|
|
FOREACH_KSE_IN_GROUP(kg, ke) {
|
|
if (ke->ke_state != KES_ONRUNQ &&
|
|
ke->ke_state != KES_THREAD)
|
|
continue;
|
|
kseq = KSEQ_CPU(ke->ke_cpu);
|
|
|
|
#ifdef SMP
|
|
/*
|
|
* On SMP if we're on the RUNQ we must adjust the transferable
|
|
* count because could be changing to or from an interrupt
|
|
* class.
|
|
*/
|
|
if (ke->ke_state == KES_ONRUNQ) {
|
|
if (KSE_CAN_MIGRATE(ke, oclass)) {
|
|
kseq->ksq_transferable--;
|
|
kseq->ksq_group->ksg_transferable--;
|
|
}
|
|
if (KSE_CAN_MIGRATE(ke, nclass)) {
|
|
kseq->ksq_transferable++;
|
|
kseq->ksq_group->ksg_transferable++;
|
|
}
|
|
}
|
|
#endif
|
|
if (oclass == PRI_TIMESHARE) {
|
|
kseq->ksq_load_timeshare--;
|
|
kseq_nice_rem(kseq, kg->kg_nice);
|
|
}
|
|
if (nclass == PRI_TIMESHARE) {
|
|
kseq->ksq_load_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)
|
|
{
|
|
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_load_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 thread *td)
|
|
{
|
|
struct kseq *kseq;
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
ke = td->td_kse;
|
|
kg = ke->ke_ksegrp;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
/* 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;
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (--ke->ke_slice > 0)
|
|
return;
|
|
/*
|
|
* We're out of time, recompute priorities and requeue.
|
|
*/
|
|
kseq = KSEQ_SELF();
|
|
kseq_load_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_load_add(kseq, ke);
|
|
td->td_flags |= TDF_NEEDRESCHED;
|
|
}
|
|
|
|
int
|
|
sched_runnable(void)
|
|
{
|
|
struct kseq *kseq;
|
|
int load;
|
|
|
|
load = 1;
|
|
|
|
kseq = KSEQ_SELF();
|
|
#ifdef SMP
|
|
if (kseq->ksq_assigned) {
|
|
mtx_lock_spin(&sched_lock);
|
|
kseq_assign(kseq);
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
#endif
|
|
if ((curthread->td_flags & TDF_IDLETD) != 0) {
|
|
if (kseq->ksq_load > 0)
|
|
goto out;
|
|
} else
|
|
if (kseq->ksq_load - 1 > 0)
|
|
goto out;
|
|
load = 0;
|
|
out:
|
|
return (load);
|
|
}
|
|
|
|
void
|
|
sched_userret(struct thread *td)
|
|
{
|
|
struct ksegrp *kg;
|
|
|
|
kg = td->td_ksegrp;
|
|
|
|
if (td->td_priority != kg->kg_user_pri) {
|
|
mtx_lock_spin(&sched_lock);
|
|
td->td_priority = kg->kg_user_pri;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
|
|
struct kse *
|
|
sched_choose(void)
|
|
{
|
|
struct kseq *kseq;
|
|
struct kse *ke;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
kseq = KSEQ_SELF();
|
|
#ifdef SMP
|
|
restart:
|
|
if (kseq->ksq_assigned)
|
|
kseq_assign(kseq);
|
|
#endif
|
|
ke = kseq_choose(kseq);
|
|
if (ke) {
|
|
#ifdef SMP
|
|
if (ke->ke_ksegrp->kg_pri_class == PRI_IDLE)
|
|
if (kseq_idled(kseq) == 0)
|
|
goto restart;
|
|
#endif
|
|
kseq_runq_rem(kseq, 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 (kseq_idled(kseq) == 0)
|
|
goto restart;
|
|
#endif
|
|
return (NULL);
|
|
}
|
|
|
|
void
|
|
sched_add(struct thread *td)
|
|
{
|
|
struct kseq *kseq;
|
|
struct ksegrp *kg;
|
|
struct kse *ke;
|
|
int class;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
ke = td->td_kse;
|
|
kg = td->td_ksegrp;
|
|
if (ke->ke_flags & KEF_ASSIGNED)
|
|
return;
|
|
kseq = KSEQ_SELF();
|
|
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));
|
|
|
|
class = PRI_BASE(kg->kg_pri_class);
|
|
switch (class) {
|
|
case PRI_ITHD:
|
|
case PRI_REALTIME:
|
|
ke->ke_runq = kseq->ksq_curr;
|
|
ke->ke_slice = SCHED_SLICE_MAX;
|
|
ke->ke_cpu = PCPU_GET(cpuid);
|
|
break;
|
|
case PRI_TIMESHARE:
|
|
if (SCHED_CURR(kg, ke))
|
|
ke->ke_runq = kseq->ksq_curr;
|
|
else
|
|
ke->ke_runq = kseq->ksq_next;
|
|
break;
|
|
case PRI_IDLE:
|
|
/*
|
|
* 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.");
|
|
break;
|
|
}
|
|
#ifdef SMP
|
|
if (ke->ke_cpu != PCPU_GET(cpuid)) {
|
|
ke->ke_runq = NULL;
|
|
kseq_notify(ke, ke->ke_cpu);
|
|
return;
|
|
}
|
|
/*
|
|
* If we had been idle, clear our bit in the group and potentially
|
|
* the global bitmap. If not, see if we should transfer this thread.
|
|
*/
|
|
if ((class == PRI_TIMESHARE || class == PRI_REALTIME) &&
|
|
(kseq->ksq_group->ksg_idlemask & PCPU_GET(cpumask)) != 0) {
|
|
/*
|
|
* Check to see if our group is unidling, and if so, remove it
|
|
* from the global idle mask.
|
|
*/
|
|
if (kseq->ksq_group->ksg_idlemask ==
|
|
kseq->ksq_group->ksg_cpumask)
|
|
atomic_clear_int(&kseq_idle, kseq->ksq_group->ksg_mask);
|
|
/*
|
|
* Now remove ourselves from the group specific idle mask.
|
|
*/
|
|
kseq->ksq_group->ksg_idlemask &= ~PCPU_GET(cpumask);
|
|
} else if (kseq->ksq_load > 1 && KSE_CAN_MIGRATE(ke, class))
|
|
if (kseq_transfer(kseq, ke, class))
|
|
return;
|
|
#endif
|
|
if (td->td_priority < curthread->td_priority)
|
|
curthread->td_flags |= TDF_NEEDRESCHED;
|
|
|
|
ke->ke_ksegrp->kg_runq_kses++;
|
|
ke->ke_state = KES_ONRUNQ;
|
|
|
|
kseq_runq_add(kseq, ke);
|
|
kseq_load_add(kseq, ke);
|
|
}
|
|
|
|
void
|
|
sched_rem(struct thread *td)
|
|
{
|
|
struct kseq *kseq;
|
|
struct kse *ke;
|
|
|
|
ke = td->td_kse;
|
|
/*
|
|
* It is safe to just return here because sched_rem() is only ever
|
|
* used in places where we're immediately going to add the
|
|
* kse back on again. In that case it'll be added with the correct
|
|
* thread and priority when the caller drops the sched_lock.
|
|
*/
|
|
if (ke->ke_flags & KEF_ASSIGNED)
|
|
return;
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
KASSERT((ke->ke_state == KES_ONRUNQ),
|
|
("sched_rem: KSE not on run queue"));
|
|
|
|
ke->ke_state = KES_THREAD;
|
|
ke->ke_ksegrp->kg_runq_kses--;
|
|
kseq = KSEQ_CPU(ke->ke_cpu);
|
|
kseq_runq_rem(kseq, ke);
|
|
kseq_load_rem(kseq, ke);
|
|
}
|
|
|
|
fixpt_t
|
|
sched_pctcpu(struct thread *td)
|
|
{
|
|
fixpt_t pctcpu;
|
|
struct kse *ke;
|
|
|
|
pctcpu = 0;
|
|
ke = td->td_kse;
|
|
if (ke == NULL)
|
|
return (0);
|
|
|
|
mtx_lock_spin(&sched_lock);
|
|
if (ke->ke_ticks) {
|
|
int rtick;
|
|
|
|
/*
|
|
* Don't update more frequently than twice a second. Allowing
|
|
* this causes the cpu usage to decay away too quickly due to
|
|
* rounding errors.
|
|
*/
|
|
if (ke->ke_ftick + SCHED_CPU_TICKS < ke->ke_ltick ||
|
|
ke->ke_ltick < (ticks - (hz / 2)))
|
|
sched_pctcpu_update(ke);
|
|
/* How many rtick per second ? */
|
|
rtick = min(ke->ke_ticks / SCHED_CPU_TIME, SCHED_CPU_TICKS);
|
|
pctcpu = (FSCALE * ((FSCALE * rtick)/realstathz)) >> FSHIFT;
|
|
}
|
|
|
|
ke->ke_proc->p_swtime = ke->ke_ltick - ke->ke_ftick;
|
|
mtx_unlock_spin(&sched_lock);
|
|
|
|
return (pctcpu);
|
|
}
|
|
|
|
void
|
|
sched_bind(struct thread *td, int cpu)
|
|
{
|
|
struct kse *ke;
|
|
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
ke = td->td_kse;
|
|
ke->ke_flags |= KEF_BOUND;
|
|
#ifdef SMP
|
|
if (PCPU_GET(cpuid) == cpu)
|
|
return;
|
|
/* sched_rem without the runq_remove */
|
|
ke->ke_state = KES_THREAD;
|
|
ke->ke_ksegrp->kg_runq_kses--;
|
|
kseq_load_rem(KSEQ_CPU(ke->ke_cpu), ke);
|
|
kseq_notify(ke, cpu);
|
|
/* When we return from mi_switch we'll be on the correct cpu. */
|
|
mi_switch(SW_VOL);
|
|
#endif
|
|
}
|
|
|
|
void
|
|
sched_unbind(struct thread *td)
|
|
{
|
|
mtx_assert(&sched_lock, MA_OWNED);
|
|
td->td_kse->ke_flags &= ~KEF_BOUND;
|
|
}
|
|
|
|
int
|
|
sched_load(void)
|
|
{
|
|
#ifdef SMP
|
|
int total;
|
|
int i;
|
|
|
|
total = 0;
|
|
for (i = 0; i <= ksg_maxid; i++)
|
|
total += KSEQ_GROUP(i)->ksg_load;
|
|
return (total);
|
|
#else
|
|
return (KSEQ_SELF()->ksq_sysload);
|
|
#endif
|
|
}
|
|
|
|
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));
|
|
}
|