486a941418
a thread is an idle thread, just see if it has the IDLETD flag set. That flag will probably move to the pflags word as it's permenent and never chenges for the life of the system so it doesn't need locking.
588 lines
15 KiB
C
588 lines
15 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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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, this list of conditions and the following 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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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_device_polling.h"
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#include "opt_hwpmc_hooks.h"
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#include "opt_ntp.h"
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#include "opt_watchdog.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/callout.h>
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#include <sys/kdb.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/ktr.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/signalvar.h>
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#include <sys/smp.h>
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#include <vm/vm.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <sys/sysctl.h>
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#include <sys/bus.h>
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#include <sys/interrupt.h>
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#include <sys/limits.h>
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#include <sys/timetc.h>
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#ifdef GPROF
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#include <sys/gmon.h>
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#endif
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#ifdef HWPMC_HOOKS
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#include <sys/pmckern.h>
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#endif
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#ifdef DEVICE_POLLING
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extern void hardclock_device_poll(void);
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#endif /* DEVICE_POLLING */
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static void initclocks(void *dummy);
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SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
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/* Some of these don't belong here, but it's easiest to concentrate them. */
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long cp_time[CPUSTATES];
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static int
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sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS)
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{
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int error;
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#ifdef SCTL_MASK32
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int i;
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unsigned int cp_time32[CPUSTATES];
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if (req->flags & SCTL_MASK32) {
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if (!req->oldptr)
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return SYSCTL_OUT(req, 0, sizeof(cp_time32));
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for (i = 0; i < CPUSTATES; i++)
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cp_time32[i] = (unsigned int)cp_time[i];
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error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
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} else
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#endif
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{
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if (!req->oldptr)
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return SYSCTL_OUT(req, 0, sizeof(cp_time));
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error = SYSCTL_OUT(req, cp_time, sizeof(cp_time));
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}
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return error;
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}
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SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD,
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0,0, sysctl_kern_cp_time, "LU", "CPU time statistics");
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#ifdef SW_WATCHDOG
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#include <sys/watchdog.h>
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static int watchdog_ticks;
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static int watchdog_enabled;
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static void watchdog_fire(void);
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static void watchdog_config(void *, u_int, int *);
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#endif /* SW_WATCHDOG */
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/*
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* Clock handling routines.
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*
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* This code is written to operate with two timers that run independently of
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* each other.
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*
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* The main timer, running hz times per second, is used to trigger interval
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* timers, timeouts and rescheduling as needed.
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*
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* The second timer handles kernel and user profiling,
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* and does resource use estimation. If the second timer is programmable,
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* it is randomized to avoid aliasing between the two clocks. For example,
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* the randomization prevents an adversary from always giving up the cpu
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* just before its quantum expires. Otherwise, it would never accumulate
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* cpu ticks. The mean frequency of the second timer is stathz.
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*
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* If no second timer exists, stathz will be zero; in this case we drive
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* profiling and statistics off the main clock. This WILL NOT be accurate;
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* do not do it unless absolutely necessary.
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*
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* The statistics clock may (or may not) be run at a higher rate while
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* profiling. This profile clock runs at profhz. We require that profhz
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* be an integral multiple of stathz.
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*
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* If the statistics clock is running fast, it must be divided by the ratio
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* profhz/stathz for statistics. (For profiling, every tick counts.)
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*
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* Time-of-day is maintained using a "timecounter", which may or may
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* not be related to the hardware generating the above mentioned
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* interrupts.
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*/
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int stathz;
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int profhz;
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int profprocs;
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int ticks;
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int psratio;
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/*
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* Initialize clock frequencies and start both clocks running.
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*/
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/* ARGSUSED*/
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static void
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initclocks(dummy)
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void *dummy;
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{
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register int i;
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/*
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* Set divisors to 1 (normal case) and let the machine-specific
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* code do its bit.
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*/
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cpu_initclocks();
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/*
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* Compute profhz/stathz, and fix profhz if needed.
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*/
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i = stathz ? stathz : hz;
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if (profhz == 0)
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profhz = i;
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psratio = profhz / i;
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#ifdef SW_WATCHDOG
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EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0);
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#endif
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}
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/*
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* Each time the real-time timer fires, this function is called on all CPUs.
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* Note that hardclock() calls hardclock_cpu() for the boot CPU, so only
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* the other CPUs in the system need to call this function.
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*/
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void
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hardclock_cpu(int usermode)
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{
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struct pstats *pstats;
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struct thread *td = curthread;
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struct proc *p = td->td_proc;
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/*
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* Run current process's virtual and profile time, as needed.
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*/
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mtx_lock_spin_flags(&sched_lock, MTX_QUIET);
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sched_tick();
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#ifdef KSE
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#if 0 /* for now do nothing */
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if (p->p_flag & P_SA) {
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/* XXXKSE What to do? Should do more. */
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}
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#endif
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#endif
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pstats = p->p_stats;
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if (usermode &&
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timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) &&
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itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0) {
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p->p_sflag |= PS_ALRMPEND;
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td->td_flags |= TDF_ASTPENDING;
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}
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if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value) &&
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itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0) {
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p->p_sflag |= PS_PROFPEND;
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td->td_flags |= TDF_ASTPENDING;
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}
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mtx_unlock_spin_flags(&sched_lock, MTX_QUIET);
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#ifdef HWPMC_HOOKS
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if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid)))
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PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL);
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#endif
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}
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/*
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* The real-time timer, interrupting hz times per second.
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*/
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void
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hardclock(int usermode, uintfptr_t pc)
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{
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int need_softclock = 0;
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hardclock_cpu(usermode);
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tc_ticktock();
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/*
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* If no separate statistics clock is available, run it from here.
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*
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* XXX: this only works for UP
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*/
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if (stathz == 0) {
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profclock(usermode, pc);
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statclock(usermode);
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}
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#ifdef DEVICE_POLLING
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hardclock_device_poll(); /* this is very short and quick */
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#endif /* DEVICE_POLLING */
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/*
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* Process callouts at a very low cpu priority, so we don't keep the
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* relatively high clock interrupt priority any longer than necessary.
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*/
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mtx_lock_spin_flags(&callout_lock, MTX_QUIET);
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ticks++;
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if (!TAILQ_EMPTY(&callwheel[ticks & callwheelmask])) {
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need_softclock = 1;
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} else if (softticks + 1 == ticks)
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++softticks;
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mtx_unlock_spin_flags(&callout_lock, MTX_QUIET);
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/*
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* swi_sched acquires sched_lock, so we don't want to call it with
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* callout_lock held; incorrect locking order.
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*/
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if (need_softclock)
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swi_sched(softclock_ih, 0);
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#ifdef SW_WATCHDOG
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if (watchdog_enabled > 0 && --watchdog_ticks <= 0)
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watchdog_fire();
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#endif /* SW_WATCHDOG */
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}
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/*
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* Compute number of ticks in the specified amount of time.
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*/
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int
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tvtohz(tv)
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struct timeval *tv;
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{
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register unsigned long ticks;
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register long sec, usec;
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/*
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* If the number of usecs in the whole seconds part of the time
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* difference fits in a long, then the total number of usecs will
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* fit in an unsigned long. Compute the total and convert it to
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* ticks, rounding up and adding 1 to allow for the current tick
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* to expire. Rounding also depends on unsigned long arithmetic
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* to avoid overflow.
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*
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* Otherwise, if the number of ticks in the whole seconds part of
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* the time difference fits in a long, then convert the parts to
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* ticks separately and add, using similar rounding methods and
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* overflow avoidance. This method would work in the previous
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* case but it is slightly slower and assumes that hz is integral.
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*
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* Otherwise, round the time difference down to the maximum
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* representable value.
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*
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* If ints have 32 bits, then the maximum value for any timeout in
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* 10ms ticks is 248 days.
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*/
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sec = tv->tv_sec;
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usec = tv->tv_usec;
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if (usec < 0) {
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sec--;
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usec += 1000000;
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}
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if (sec < 0) {
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#ifdef DIAGNOSTIC
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if (usec > 0) {
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sec++;
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usec -= 1000000;
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}
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printf("tvotohz: negative time difference %ld sec %ld usec\n",
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sec, usec);
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#endif
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ticks = 1;
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} else if (sec <= LONG_MAX / 1000000)
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ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
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/ tick + 1;
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else if (sec <= LONG_MAX / hz)
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ticks = sec * hz
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+ ((unsigned long)usec + (tick - 1)) / tick + 1;
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else
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ticks = LONG_MAX;
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if (ticks > INT_MAX)
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ticks = INT_MAX;
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return ((int)ticks);
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}
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/*
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* Start profiling on a process.
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*
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* Kernel profiling passes proc0 which never exits and hence
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* keeps the profile clock running constantly.
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*/
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void
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startprofclock(p)
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register struct proc *p;
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{
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/*
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* XXX; Right now sched_lock protects statclock(), but perhaps
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* it should be protected later on by a time_lock, which would
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* cover psdiv, etc. as well.
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*/
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PROC_LOCK_ASSERT(p, MA_OWNED);
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if (p->p_flag & P_STOPPROF)
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return;
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if ((p->p_flag & P_PROFIL) == 0) {
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mtx_lock_spin(&sched_lock);
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p->p_flag |= P_PROFIL;
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if (++profprocs == 1)
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cpu_startprofclock();
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mtx_unlock_spin(&sched_lock);
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}
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}
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/*
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* Stop profiling on a process.
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*/
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void
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stopprofclock(p)
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register struct proc *p;
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{
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PROC_LOCK_ASSERT(p, MA_OWNED);
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if (p->p_flag & P_PROFIL) {
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if (p->p_profthreads != 0) {
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p->p_flag |= P_STOPPROF;
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while (p->p_profthreads != 0)
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msleep(&p->p_profthreads, &p->p_mtx, PPAUSE,
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"stopprof", 0);
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p->p_flag &= ~P_STOPPROF;
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}
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if ((p->p_flag & P_PROFIL) == 0)
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return;
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mtx_lock_spin(&sched_lock);
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p->p_flag &= ~P_PROFIL;
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if (--profprocs == 0)
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cpu_stopprofclock();
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mtx_unlock_spin(&sched_lock);
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}
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}
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/*
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* Statistics clock. Grab profile sample, and if divider reaches 0,
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* do process and kernel statistics. Most of the statistics are only
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* used by user-level statistics programs. The main exceptions are
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* ke->ke_uticks, p->p_rux.rux_sticks, p->p_rux.rux_iticks, and p->p_estcpu.
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* This should be called by all active processors.
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*/
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void
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statclock(int usermode)
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{
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struct rusage *ru;
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struct vmspace *vm;
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struct thread *td;
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struct proc *p;
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long rss;
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td = curthread;
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p = td->td_proc;
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mtx_lock_spin_flags(&sched_lock, MTX_QUIET);
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if (usermode) {
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/*
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* Charge the time as appropriate.
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*/
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#ifdef KSE
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if (p->p_flag & P_SA)
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thread_statclock(1);
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#endif
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td->td_uticks++;
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if (p->p_nice > NZERO)
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cp_time[CP_NICE]++;
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else
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cp_time[CP_USER]++;
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} else {
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/*
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* Came from kernel mode, so we were:
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* - handling an interrupt,
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* - doing syscall or trap work on behalf of the current
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* user process, or
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* - spinning in the idle loop.
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* Whichever it is, charge the time as appropriate.
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* Note that we charge interrupts to the current process,
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* regardless of whether they are ``for'' that process,
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* so that we know how much of its real time was spent
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* in ``non-process'' (i.e., interrupt) work.
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*/
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if ((td->td_pflags & TDP_ITHREAD) ||
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td->td_intr_nesting_level >= 2) {
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td->td_iticks++;
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cp_time[CP_INTR]++;
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} else {
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#ifdef KSE
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if (p->p_flag & P_SA)
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thread_statclock(0);
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#endif
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td->td_pticks++;
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td->td_sticks++;
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if (!TD_IS_IDLETHREAD(td))
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cp_time[CP_SYS]++;
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else
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cp_time[CP_IDLE]++;
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}
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}
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CTR4(KTR_SCHED, "statclock: %p(%s) prio %d stathz %d",
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td, td->td_proc->p_comm, td->td_priority, (stathz)?stathz:hz);
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sched_clock(td);
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/* Update resource usage integrals and maximums. */
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MPASS(p->p_stats != NULL);
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MPASS(p->p_vmspace != NULL);
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vm = p->p_vmspace;
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ru = &p->p_stats->p_ru;
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ru->ru_ixrss += pgtok(vm->vm_tsize);
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ru->ru_idrss += pgtok(vm->vm_dsize);
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ru->ru_isrss += pgtok(vm->vm_ssize);
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rss = pgtok(vmspace_resident_count(vm));
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if (ru->ru_maxrss < rss)
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ru->ru_maxrss = rss;
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mtx_unlock_spin_flags(&sched_lock, MTX_QUIET);
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}
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void
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profclock(int usermode, uintfptr_t pc)
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{
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struct thread *td;
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#ifdef GPROF
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struct gmonparam *g;
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uintfptr_t i;
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#endif
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td = curthread;
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if (usermode) {
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/*
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* Came from user mode; CPU was in user state.
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* If this process is being profiled, record the tick.
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* if there is no related user location yet, don't
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* bother trying to count it.
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*/
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if (td->td_proc->p_flag & P_PROFIL)
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addupc_intr(td, pc, 1);
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}
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#ifdef GPROF
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else {
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/*
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* Kernel statistics are just like addupc_intr, only easier.
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*/
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g = &_gmonparam;
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if (g->state == GMON_PROF_ON && pc >= g->lowpc) {
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i = PC_TO_I(g, pc);
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if (i < g->textsize) {
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KCOUNT(g, i)++;
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}
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}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Return information about system clocks.
|
|
*/
|
|
static int
|
|
sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct clockinfo clkinfo;
|
|
/*
|
|
* Construct clockinfo structure.
|
|
*/
|
|
bzero(&clkinfo, sizeof(clkinfo));
|
|
clkinfo.hz = hz;
|
|
clkinfo.tick = tick;
|
|
clkinfo.profhz = profhz;
|
|
clkinfo.stathz = stathz ? stathz : hz;
|
|
return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
|
|
}
|
|
|
|
SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
|
|
0, 0, sysctl_kern_clockrate, "S,clockinfo",
|
|
"Rate and period of various kernel clocks");
|
|
|
|
#ifdef SW_WATCHDOG
|
|
|
|
static void
|
|
watchdog_config(void *unused __unused, u_int cmd, int *error)
|
|
{
|
|
u_int u;
|
|
|
|
u = cmd & WD_INTERVAL;
|
|
if (u >= WD_TO_1SEC) {
|
|
watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz;
|
|
watchdog_enabled = 1;
|
|
*error = 0;
|
|
} else {
|
|
watchdog_enabled = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle a watchdog timeout by dumping interrupt information and
|
|
* then either dropping to DDB or panicing.
|
|
*/
|
|
static void
|
|
watchdog_fire(void)
|
|
{
|
|
int nintr;
|
|
u_int64_t inttotal;
|
|
u_long *curintr;
|
|
char *curname;
|
|
|
|
curintr = intrcnt;
|
|
curname = intrnames;
|
|
inttotal = 0;
|
|
nintr = eintrcnt - intrcnt;
|
|
|
|
printf("interrupt total\n");
|
|
while (--nintr >= 0) {
|
|
if (*curintr)
|
|
printf("%-12s %20lu\n", curname, *curintr);
|
|
curname += strlen(curname) + 1;
|
|
inttotal += *curintr++;
|
|
}
|
|
printf("Total %20ju\n", (uintmax_t)inttotal);
|
|
|
|
#ifdef KDB
|
|
kdb_backtrace();
|
|
kdb_enter("watchdog timeout");
|
|
#else
|
|
panic("watchdog timeout");
|
|
#endif /* KDB */
|
|
}
|
|
|
|
#endif /* SW_WATCHDOG */
|