freebsd-dev/sys/kern/kern_clock.c
John Baldwin a8df530ddc Mark 'ticks', 'time_second', and 'time_uptime' as volatile to prevent the
compiler from caching their values in tight loops.

Reviewed by:	bde
MFC after:	1 week
2013-01-28 19:38:13 +00:00

897 lines
22 KiB
C

/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_kdb.h"
#include "opt_device_polling.h"
#include "opt_hwpmc_hooks.h"
#include "opt_kdtrace.h"
#include "opt_ntp.h"
#include "opt_watchdog.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/sdt.h>
#include <sys/signalvar.h>
#include <sys/sleepqueue.h>
#include <sys/smp.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <sys/sysctl.h>
#include <sys/bus.h>
#include <sys/interrupt.h>
#include <sys/limits.h>
#include <sys/timetc.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif
#ifdef HWPMC_HOOKS
#include <sys/pmckern.h>
PMC_SOFT_DEFINE( , , clock, hard);
PMC_SOFT_DEFINE( , , clock, stat);
#endif
#ifdef DEVICE_POLLING
extern void hardclock_device_poll(void);
#endif /* DEVICE_POLLING */
static void initclocks(void *dummy);
SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL);
/* Spin-lock protecting profiling statistics. */
static struct mtx time_lock;
SDT_PROVIDER_DECLARE(sched);
SDT_PROBE_DEFINE2(sched, , , tick, tick, "struct thread *", "struct proc *");
static int
sysctl_kern_cp_time(SYSCTL_HANDLER_ARGS)
{
int error;
long cp_time[CPUSTATES];
#ifdef SCTL_MASK32
int i;
unsigned int cp_time32[CPUSTATES];
#endif
read_cpu_time(cp_time);
#ifdef SCTL_MASK32
if (req->flags & SCTL_MASK32) {
if (!req->oldptr)
return SYSCTL_OUT(req, 0, sizeof(cp_time32));
for (i = 0; i < CPUSTATES; i++)
cp_time32[i] = (unsigned int)cp_time[i];
error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
} else
#endif
{
if (!req->oldptr)
return SYSCTL_OUT(req, 0, sizeof(cp_time));
error = SYSCTL_OUT(req, cp_time, sizeof(cp_time));
}
return error;
}
SYSCTL_PROC(_kern, OID_AUTO, cp_time, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE,
0,0, sysctl_kern_cp_time, "LU", "CPU time statistics");
static long empty[CPUSTATES];
static int
sysctl_kern_cp_times(SYSCTL_HANDLER_ARGS)
{
struct pcpu *pcpu;
int error;
int c;
long *cp_time;
#ifdef SCTL_MASK32
unsigned int cp_time32[CPUSTATES];
int i;
#endif
if (!req->oldptr) {
#ifdef SCTL_MASK32
if (req->flags & SCTL_MASK32)
return SYSCTL_OUT(req, 0, sizeof(cp_time32) * (mp_maxid + 1));
else
#endif
return SYSCTL_OUT(req, 0, sizeof(long) * CPUSTATES * (mp_maxid + 1));
}
for (error = 0, c = 0; error == 0 && c <= mp_maxid; c++) {
if (!CPU_ABSENT(c)) {
pcpu = pcpu_find(c);
cp_time = pcpu->pc_cp_time;
} else {
cp_time = empty;
}
#ifdef SCTL_MASK32
if (req->flags & SCTL_MASK32) {
for (i = 0; i < CPUSTATES; i++)
cp_time32[i] = (unsigned int)cp_time[i];
error = SYSCTL_OUT(req, cp_time32, sizeof(cp_time32));
} else
#endif
error = SYSCTL_OUT(req, cp_time, sizeof(long) * CPUSTATES);
}
return error;
}
SYSCTL_PROC(_kern, OID_AUTO, cp_times, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE,
0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics");
#ifdef DEADLKRES
static const char *blessed[] = {
"getblk",
"so_snd_sx",
"so_rcv_sx",
NULL
};
static int slptime_threshold = 1800;
static int blktime_threshold = 900;
static int sleepfreq = 3;
static void
deadlkres(void)
{
struct proc *p;
struct thread *td;
void *wchan;
int blkticks, i, slpticks, slptype, tryl, tticks;
tryl = 0;
for (;;) {
blkticks = blktime_threshold * hz;
slpticks = slptime_threshold * hz;
/*
* Avoid to sleep on the sx_lock in order to avoid a possible
* priority inversion problem leading to starvation.
* If the lock can't be held after 100 tries, panic.
*/
if (!sx_try_slock(&allproc_lock)) {
if (tryl > 100)
panic("%s: possible deadlock detected on allproc_lock\n",
__func__);
tryl++;
pause("allproc", sleepfreq * hz);
continue;
}
tryl = 0;
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state == PRS_NEW) {
PROC_UNLOCK(p);
continue;
}
FOREACH_THREAD_IN_PROC(p, td) {
/*
* Once a thread is found in "interesting"
* state a possible ticks wrap-up needs to be
* checked.
*/
thread_lock(td);
if (TD_ON_LOCK(td) && ticks < td->td_blktick) {
/*
* The thread should be blocked on a
* turnstile, simply check if the
* turnstile channel is in good state.
*/
MPASS(td->td_blocked != NULL);
tticks = ticks - td->td_blktick;
thread_unlock(td);
if (tticks > blkticks) {
/*
* Accordingly with provided
* thresholds, this thread is
* stuck for too long on a
* turnstile.
*/
PROC_UNLOCK(p);
sx_sunlock(&allproc_lock);
panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
__func__, td, tticks);
}
} else if (TD_IS_SLEEPING(td) &&
TD_ON_SLEEPQ(td) &&
ticks < td->td_blktick) {
/*
* Check if the thread is sleeping on a
* lock, otherwise skip the check.
* Drop the thread lock in order to
* avoid a LOR with the sleepqueue
* spinlock.
*/
wchan = td->td_wchan;
tticks = ticks - td->td_slptick;
thread_unlock(td);
slptype = sleepq_type(wchan);
if ((slptype == SLEEPQ_SX ||
slptype == SLEEPQ_LK) &&
tticks > slpticks) {
/*
* Accordingly with provided
* thresholds, this thread is
* stuck for too long on a
* sleepqueue.
* However, being on a
* sleepqueue, we might still
* check for the blessed
* list.
*/
tryl = 0;
for (i = 0; blessed[i] != NULL;
i++) {
if (!strcmp(blessed[i],
td->td_wmesg)) {
tryl = 1;
break;
}
}
if (tryl != 0) {
tryl = 0;
continue;
}
PROC_UNLOCK(p);
sx_sunlock(&allproc_lock);
panic("%s: possible deadlock detected for %p, blocked for %d ticks\n",
__func__, td, tticks);
}
} else
thread_unlock(td);
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
/* Sleep for sleepfreq seconds. */
pause("-", sleepfreq * hz);
}
}
static struct kthread_desc deadlkres_kd = {
"deadlkres",
deadlkres,
(struct thread **)NULL
};
SYSINIT(deadlkres, SI_SUB_CLOCKS, SI_ORDER_ANY, kthread_start, &deadlkres_kd);
static SYSCTL_NODE(_debug, OID_AUTO, deadlkres, CTLFLAG_RW, 0,
"Deadlock resolver");
SYSCTL_INT(_debug_deadlkres, OID_AUTO, slptime_threshold, CTLFLAG_RW,
&slptime_threshold, 0,
"Number of seconds within is valid to sleep on a sleepqueue");
SYSCTL_INT(_debug_deadlkres, OID_AUTO, blktime_threshold, CTLFLAG_RW,
&blktime_threshold, 0,
"Number of seconds within is valid to block on a turnstile");
SYSCTL_INT(_debug_deadlkres, OID_AUTO, sleepfreq, CTLFLAG_RW, &sleepfreq, 0,
"Number of seconds between any deadlock resolver thread run");
#endif /* DEADLKRES */
void
read_cpu_time(long *cp_time)
{
struct pcpu *pc;
int i, j;
/* Sum up global cp_time[]. */
bzero(cp_time, sizeof(long) * CPUSTATES);
CPU_FOREACH(i) {
pc = pcpu_find(i);
for (j = 0; j < CPUSTATES; j++)
cp_time[j] += pc->pc_cp_time[j];
}
}
#ifdef SW_WATCHDOG
#include <sys/watchdog.h>
static int watchdog_ticks;
static int watchdog_enabled;
static void watchdog_fire(void);
static void watchdog_config(void *, u_int, int *);
#endif /* SW_WATCHDOG */
/*
* Clock handling routines.
*
* This code is written to operate with two timers that run independently of
* each other.
*
* The main timer, running hz times per second, is used to trigger interval
* timers, timeouts and rescheduling as needed.
*
* The second timer handles kernel and user profiling,
* and does resource use estimation. If the second timer is programmable,
* it is randomized to avoid aliasing between the two clocks. For example,
* the randomization prevents an adversary from always giving up the cpu
* just before its quantum expires. Otherwise, it would never accumulate
* cpu ticks. The mean frequency of the second timer is stathz.
*
* If no second timer exists, stathz will be zero; in this case we drive
* profiling and statistics off the main clock. This WILL NOT be accurate;
* do not do it unless absolutely necessary.
*
* The statistics clock may (or may not) be run at a higher rate while
* profiling. This profile clock runs at profhz. We require that profhz
* be an integral multiple of stathz.
*
* If the statistics clock is running fast, it must be divided by the ratio
* profhz/stathz for statistics. (For profiling, every tick counts.)
*
* Time-of-day is maintained using a "timecounter", which may or may
* not be related to the hardware generating the above mentioned
* interrupts.
*/
int stathz;
int profhz;
int profprocs;
volatile int ticks;
int psratio;
static DPCPU_DEFINE(int, pcputicks); /* Per-CPU version of ticks. */
static int global_hardclock_run = 0;
/*
* Initialize clock frequencies and start both clocks running.
*/
/* ARGSUSED*/
static void
initclocks(dummy)
void *dummy;
{
register int i;
/*
* Set divisors to 1 (normal case) and let the machine-specific
* code do its bit.
*/
mtx_init(&time_lock, "time lock", NULL, MTX_DEF);
cpu_initclocks();
/*
* Compute profhz/stathz, and fix profhz if needed.
*/
i = stathz ? stathz : hz;
if (profhz == 0)
profhz = i;
psratio = profhz / i;
#ifdef SW_WATCHDOG
EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0);
#endif
}
/*
* Each time the real-time timer fires, this function is called on all CPUs.
* Note that hardclock() calls hardclock_cpu() for the boot CPU, so only
* the other CPUs in the system need to call this function.
*/
void
hardclock_cpu(int usermode)
{
struct pstats *pstats;
struct thread *td = curthread;
struct proc *p = td->td_proc;
int flags;
/*
* Run current process's virtual and profile time, as needed.
*/
pstats = p->p_stats;
flags = 0;
if (usermode &&
timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) {
PROC_SLOCK(p);
if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
flags |= TDF_ALRMPEND | TDF_ASTPENDING;
PROC_SUNLOCK(p);
}
if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) {
PROC_SLOCK(p);
if (itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
flags |= TDF_PROFPEND | TDF_ASTPENDING;
PROC_SUNLOCK(p);
}
thread_lock(td);
sched_tick(1);
td->td_flags |= flags;
thread_unlock(td);
#ifdef HWPMC_HOOKS
if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid)))
PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL);
if (td->td_intr_frame != NULL)
PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame);
#endif
callout_tick();
}
/*
* The real-time timer, interrupting hz times per second.
*/
void
hardclock(int usermode, uintfptr_t pc)
{
atomic_add_int(&ticks, 1);
hardclock_cpu(usermode);
tc_ticktock(1);
cpu_tick_calibration();
/*
* If no separate statistics clock is available, run it from here.
*
* XXX: this only works for UP
*/
if (stathz == 0) {
profclock(usermode, pc);
statclock(usermode);
}
#ifdef DEVICE_POLLING
hardclock_device_poll(); /* this is very short and quick */
#endif /* DEVICE_POLLING */
#ifdef SW_WATCHDOG
if (watchdog_enabled > 0 && --watchdog_ticks <= 0)
watchdog_fire();
#endif /* SW_WATCHDOG */
}
void
hardclock_cnt(int cnt, int usermode)
{
struct pstats *pstats;
struct thread *td = curthread;
struct proc *p = td->td_proc;
int *t = DPCPU_PTR(pcputicks);
int flags, global, newticks;
#ifdef SW_WATCHDOG
int i;
#endif /* SW_WATCHDOG */
/*
* Update per-CPU and possibly global ticks values.
*/
*t += cnt;
do {
global = ticks;
newticks = *t - global;
if (newticks <= 0) {
if (newticks < -1)
*t = global - 1;
newticks = 0;
break;
}
} while (!atomic_cmpset_int(&ticks, global, *t));
/*
* Run current process's virtual and profile time, as needed.
*/
pstats = p->p_stats;
flags = 0;
if (usermode &&
timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) {
PROC_SLOCK(p);
if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL],
tick * cnt) == 0)
flags |= TDF_ALRMPEND | TDF_ASTPENDING;
PROC_SUNLOCK(p);
}
if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) {
PROC_SLOCK(p);
if (itimerdecr(&pstats->p_timer[ITIMER_PROF],
tick * cnt) == 0)
flags |= TDF_PROFPEND | TDF_ASTPENDING;
PROC_SUNLOCK(p);
}
thread_lock(td);
sched_tick(cnt);
td->td_flags |= flags;
thread_unlock(td);
#ifdef HWPMC_HOOKS
if (PMC_CPU_HAS_SAMPLES(PCPU_GET(cpuid)))
PMC_CALL_HOOK_UNLOCKED(curthread, PMC_FN_DO_SAMPLES, NULL);
if (td->td_intr_frame != NULL)
PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame);
#endif
callout_tick();
/* We are in charge to handle this tick duty. */
if (newticks > 0) {
/* Dangerous and no need to call these things concurrently. */
if (atomic_cmpset_acq_int(&global_hardclock_run, 0, 1)) {
tc_ticktock(newticks);
#ifdef DEVICE_POLLING
/* This is very short and quick. */
hardclock_device_poll();
#endif /* DEVICE_POLLING */
atomic_store_rel_int(&global_hardclock_run, 0);
}
#ifdef SW_WATCHDOG
if (watchdog_enabled > 0) {
i = atomic_fetchadd_int(&watchdog_ticks, -newticks);
if (i > 0 && i <= newticks)
watchdog_fire();
}
#endif /* SW_WATCHDOG */
}
if (curcpu == CPU_FIRST())
cpu_tick_calibration();
}
void
hardclock_sync(int cpu)
{
int *t = DPCPU_ID_PTR(cpu, pcputicks);
*t = ticks;
}
/*
* Compute number of ticks in the specified amount of time.
*/
int
tvtohz(tv)
struct timeval *tv;
{
register unsigned long ticks;
register long sec, usec;
/*
* If the number of usecs in the whole seconds part of the time
* difference fits in a long, then the total number of usecs will
* fit in an unsigned long. Compute the total and convert it to
* ticks, rounding up and adding 1 to allow for the current tick
* to expire. Rounding also depends on unsigned long arithmetic
* to avoid overflow.
*
* Otherwise, if the number of ticks in the whole seconds part of
* the time difference fits in a long, then convert the parts to
* ticks separately and add, using similar rounding methods and
* overflow avoidance. This method would work in the previous
* case but it is slightly slower and assumes that hz is integral.
*
* Otherwise, round the time difference down to the maximum
* representable value.
*
* If ints have 32 bits, then the maximum value for any timeout in
* 10ms ticks is 248 days.
*/
sec = tv->tv_sec;
usec = tv->tv_usec;
if (usec < 0) {
sec--;
usec += 1000000;
}
if (sec < 0) {
#ifdef DIAGNOSTIC
if (usec > 0) {
sec++;
usec -= 1000000;
}
printf("tvotohz: negative time difference %ld sec %ld usec\n",
sec, usec);
#endif
ticks = 1;
} else if (sec <= LONG_MAX / 1000000)
ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
/ tick + 1;
else if (sec <= LONG_MAX / hz)
ticks = sec * hz
+ ((unsigned long)usec + (tick - 1)) / tick + 1;
else
ticks = LONG_MAX;
if (ticks > INT_MAX)
ticks = INT_MAX;
return ((int)ticks);
}
/*
* Start profiling on a process.
*
* Kernel profiling passes proc0 which never exits and hence
* keeps the profile clock running constantly.
*/
void
startprofclock(p)
register struct proc *p;
{
PROC_LOCK_ASSERT(p, MA_OWNED);
if (p->p_flag & P_STOPPROF)
return;
if ((p->p_flag & P_PROFIL) == 0) {
p->p_flag |= P_PROFIL;
mtx_lock(&time_lock);
if (++profprocs == 1)
cpu_startprofclock();
mtx_unlock(&time_lock);
}
}
/*
* Stop profiling on a process.
*/
void
stopprofclock(p)
register struct proc *p;
{
PROC_LOCK_ASSERT(p, MA_OWNED);
if (p->p_flag & P_PROFIL) {
if (p->p_profthreads != 0) {
p->p_flag |= P_STOPPROF;
while (p->p_profthreads != 0)
msleep(&p->p_profthreads, &p->p_mtx, PPAUSE,
"stopprof", 0);
p->p_flag &= ~P_STOPPROF;
}
if ((p->p_flag & P_PROFIL) == 0)
return;
p->p_flag &= ~P_PROFIL;
mtx_lock(&time_lock);
if (--profprocs == 0)
cpu_stopprofclock();
mtx_unlock(&time_lock);
}
}
/*
* Statistics clock. Updates rusage information and calls the scheduler
* to adjust priorities of the active thread.
*
* This should be called by all active processors.
*/
void
statclock(int usermode)
{
statclock_cnt(1, usermode);
}
void
statclock_cnt(int cnt, int usermode)
{
struct rusage *ru;
struct vmspace *vm;
struct thread *td;
struct proc *p;
long rss;
long *cp_time;
td = curthread;
p = td->td_proc;
cp_time = (long *)PCPU_PTR(cp_time);
if (usermode) {
/*
* Charge the time as appropriate.
*/
td->td_uticks += cnt;
if (p->p_nice > NZERO)
cp_time[CP_NICE] += cnt;
else
cp_time[CP_USER] += cnt;
} else {
/*
* Came from kernel mode, so we were:
* - handling an interrupt,
* - doing syscall or trap work on behalf of the current
* user process, or
* - spinning in the idle loop.
* Whichever it is, charge the time as appropriate.
* Note that we charge interrupts to the current process,
* regardless of whether they are ``for'' that process,
* so that we know how much of its real time was spent
* in ``non-process'' (i.e., interrupt) work.
*/
if ((td->td_pflags & TDP_ITHREAD) ||
td->td_intr_nesting_level >= 2) {
td->td_iticks += cnt;
cp_time[CP_INTR] += cnt;
} else {
td->td_pticks += cnt;
td->td_sticks += cnt;
if (!TD_IS_IDLETHREAD(td))
cp_time[CP_SYS] += cnt;
else
cp_time[CP_IDLE] += cnt;
}
}
/* Update resource usage integrals and maximums. */
MPASS(p->p_vmspace != NULL);
vm = p->p_vmspace;
ru = &td->td_ru;
ru->ru_ixrss += pgtok(vm->vm_tsize) * cnt;
ru->ru_idrss += pgtok(vm->vm_dsize) * cnt;
ru->ru_isrss += pgtok(vm->vm_ssize) * cnt;
rss = pgtok(vmspace_resident_count(vm));
if (ru->ru_maxrss < rss)
ru->ru_maxrss = rss;
KTR_POINT2(KTR_SCHED, "thread", sched_tdname(td), "statclock",
"prio:%d", td->td_priority, "stathz:%d", (stathz)?stathz:hz);
SDT_PROBE2(sched, , , tick, td, td->td_proc);
thread_lock_flags(td, MTX_QUIET);
for ( ; cnt > 0; cnt--)
sched_clock(td);
thread_unlock(td);
#ifdef HWPMC_HOOKS
if (td->td_intr_frame != NULL)
PMC_SOFT_CALL_TF( , , clock, stat, td->td_intr_frame);
#endif
}
void
profclock(int usermode, uintfptr_t pc)
{
profclock_cnt(1, usermode, pc);
}
void
profclock_cnt(int cnt, int usermode, uintfptr_t pc)
{
struct thread *td;
#ifdef GPROF
struct gmonparam *g;
uintfptr_t i;
#endif
td = curthread;
if (usermode) {
/*
* Came from user mode; CPU was in user state.
* If this process is being profiled, record the tick.
* if there is no related user location yet, don't
* bother trying to count it.
*/
if (td->td_proc->p_flag & P_PROFIL)
addupc_intr(td, pc, cnt);
}
#ifdef GPROF
else {
/*
* Kernel statistics are just like addupc_intr, only easier.
*/
g = &_gmonparam;
if (g->state == GMON_PROF_ON && pc >= g->lowpc) {
i = PC_TO_I(g, pc);
if (i < g->textsize) {
KCOUNT(g, i) += cnt;
}
}
}
#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|CTLFLAG_MPSAFE,
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 panicking.
*/
static void
watchdog_fire(void)
{
int nintr;
uint64_t inttotal;
u_long *curintr;
char *curname;
curintr = intrcnt;
curname = intrnames;
inttotal = 0;
nintr = sintrcnt / sizeof(u_long);
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);
#if defined(KDB) && !defined(KDB_UNATTENDED)
kdb_backtrace();
kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout");
#else
panic("watchdog timeout");
#endif
}
#endif /* SW_WATCHDOG */