freebsd-dev/sys/kern/kern_clock.c
Konstantin Belousov c6d31b8306 AST: rework
Make most AST handlers dynamically registered.  This allows to have
subsystem-specific handler source located in the subsystem files,
instead of making subr_trap.c aware of it.  For instance, signal
delivery code on return to userspace is now moved to kern_sig.c.

Also, it allows to have some handlers designated as the cleanup (kclear)
type, which are called both at AST and on thread/process exit.  For
instance, ast(), exit1(), and NFS server no longer need to be aware
about UFS softdep processing.

The dynamic registration also allows third-party modules to register AST
handlers if needed.  There is one caveat with loadable modules: the
code does not make any effort to ensure that the module is not unloaded
before all threads processed through AST handler in it.  In fact, this
is already present behavior for hwpmc.ko and ufs.ko.  I do not think it
is worth the efforts and the runtime overhead to try to fix it.

Reviewed by:	markj
Tested by:	emaste (arm64), pho
Discussed with:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D35888
2022-08-02 21:11:09 +03:00

864 lines
22 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
* 3. 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_ntp.h"
#include "opt_watchdog.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/epoch.h>
#include <sys/eventhandler.h>
#include <sys/gtaskqueue.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);
PMC_SOFT_DEFINE_EX( , , clock, prof, \
cpu_startprofclock, cpu_stopprofclock);
#endif
#ifdef DEVICE_POLLING
extern void hardclock_device_poll(void);
#endif /* DEVICE_POLLING */
/* Spin-lock protecting profiling statistics. */
static struct mtx time_lock;
SDT_PROVIDER_DECLARE(sched);
SDT_PROBE_DEFINE2(sched, , , 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
deadlres_td_on_lock(struct proc *p, struct thread *td, int blkticks)
{
int tticks;
sx_assert(&allproc_lock, SX_LOCKED);
PROC_LOCK_ASSERT(p, MA_OWNED);
THREAD_LOCK_ASSERT(td, MA_OWNED);
/*
* 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;
if (tticks > blkticks)
/*
* Accordingly with provided thresholds, this thread is stuck
* for too long on a turnstile.
*/
panic("%s: possible deadlock detected for %p (%s), "
"blocked for %d ticks\n", __func__,
td, sched_tdname(td), tticks);
}
static void
deadlres_td_sleep_q(struct proc *p, struct thread *td, int slpticks)
{
const void *wchan;
int i, slptype, tticks;
sx_assert(&allproc_lock, SX_LOCKED);
PROC_LOCK_ASSERT(p, MA_OWNED);
THREAD_LOCK_ASSERT(td, MA_OWNED);
/*
* 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;
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.
*/
for (i = 0; blessed[i] != NULL; i++)
if (!strcmp(blessed[i], td->td_wmesg))
return;
panic("%s: possible deadlock detected for %p (%s), "
"blocked for %d ticks\n", __func__,
td, sched_tdname(td), tticks);
}
}
static void
deadlkres(void)
{
struct proc *p;
struct thread *td;
int blkticks, slpticks, tryl;
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) {
thread_lock(td);
if (TD_ON_LOCK(td))
deadlres_td_on_lock(p, td,
blkticks);
else if (TD_IS_SLEEPING(td))
deadlres_td_sleep_q(p, td,
slpticks);
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 | CTLFLAG_MPSAFE, 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];
}
}
#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 *);
static void
watchdog_attach(void)
{
EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0);
}
/*
* 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;
DPCPU_DEFINE_STATIC(int, pcputicks); /* Per-CPU version of ticks. */
#ifdef DEVICE_POLLING
static int devpoll_run = 0;
#endif
static void
ast_oweupc(struct thread *td, int tda __unused)
{
if ((td->td_proc->p_flag & P_PROFIL) == 0)
return;
addupc_task(td, td->td_profil_addr, td->td_profil_ticks);
td->td_profil_ticks = 0;
td->td_pflags &= ~TDP_OWEUPC;
}
static void
ast_alrm(struct thread *td, int tda __unused)
{
struct proc *p;
p = td->td_proc;
PROC_LOCK(p);
kern_psignal(p, SIGVTALRM);
PROC_UNLOCK(p);
}
static void
ast_prof(struct thread *td, int tda __unused)
{
struct proc *p;
p = td->td_proc;
PROC_LOCK(p);
kern_psignal(p, SIGPROF);
PROC_UNLOCK(p);
}
/*
* Initialize clock frequencies and start both clocks running.
*/
static void
initclocks(void *dummy __unused)
{
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;
ast_register(TDA_OWEUPC, ASTR_ASTF_REQUIRED, 0, ast_oweupc);
ast_register(TDA_ALRM, ASTR_ASTF_REQUIRED, 0, ast_alrm);
ast_register(TDA_PROF, ASTR_ASTF_REQUIRED, 0, ast_prof);
#ifdef SW_WATCHDOG
/* Enable hardclock watchdog now, even if a hardware watchdog exists. */
watchdog_attach();
#else
/* Volunteer to run a software watchdog. */
if (wdog_software_attach == NULL)
wdog_software_attach = watchdog_attach;
#endif
}
SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL);
static __noinline void
hardclock_itimer(struct thread *td, struct pstats *pstats, int cnt, int usermode)
{
struct proc *p;
int ast;
ast = 0;
p = td->td_proc;
if (usermode &&
timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value)) {
PROC_ITIMLOCK(p);
if (itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL],
tick * cnt) == 0)
ast |= TDAI(TDA_ALRM);
PROC_ITIMUNLOCK(p);
}
if (timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)) {
PROC_ITIMLOCK(p);
if (itimerdecr(&pstats->p_timer[ITIMER_PROF],
tick * cnt) == 0)
ast |= TDAI(TDA_PROF);
PROC_ITIMUNLOCK(p);
}
if (ast != 0)
ast_sched_mask(td, ast);
}
void
hardclock(int cnt, int usermode)
{
struct pstats *pstats;
struct thread *td = curthread;
struct proc *p = td->td_proc;
int *t = DPCPU_PTR(pcputicks);
int global, i, newticks;
/*
* Update per-CPU and possibly global ticks values.
*/
*t += cnt;
global = ticks;
do {
newticks = *t - global;
if (newticks <= 0) {
if (newticks < -1)
*t = global - 1;
newticks = 0;
break;
}
} while (!atomic_fcmpset_int(&ticks, &global, *t));
/*
* Run current process's virtual and profile time, as needed.
*/
pstats = p->p_stats;
if (__predict_false(
timevalisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) ||
timevalisset(&pstats->p_timer[ITIMER_PROF].it_value)))
hardclock_itimer(td, pstats, cnt, usermode);
#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
/* We are in charge to handle this tick duty. */
if (newticks > 0) {
tc_ticktock(newticks);
#ifdef DEVICE_POLLING
/* Dangerous and no need to call these things concurrently. */
if (atomic_cmpset_acq_int(&devpoll_run, 0, 1)) {
/* This is very short and quick. */
hardclock_device_poll();
atomic_store_rel_int(&devpoll_run, 0);
}
#endif /* DEVICE_POLLING */
if (watchdog_enabled > 0) {
i = atomic_fetchadd_int(&watchdog_ticks, -newticks);
if (i > 0 && i <= newticks)
watchdog_fire();
}
intr_event_handle(clk_intr_event, NULL);
}
if (curcpu == CPU_FIRST())
cpu_tick_calibration();
if (__predict_false(DPCPU_GET(epoch_cb_count)))
GROUPTASK_ENQUEUE(DPCPU_PTR(epoch_cb_task));
}
void
hardclock_sync(int cpu)
{
int *t;
KASSERT(!CPU_ABSENT(cpu), ("Absent CPU %d", cpu));
t = DPCPU_ID_PTR(cpu, pcputicks);
*t = ticks;
}
/*
* Compute number of ticks in the specified amount of time.
*/
int
tvtohz(struct timeval *tv)
{
unsigned long ticks;
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 = howmany(sec * 1000000 + (unsigned long)usec, tick) + 1;
else if (sec <= LONG_MAX / hz)
ticks = sec * hz
+ howmany((unsigned long)usec, 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(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(struct proc *p)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
if (p->p_flag & P_PROFIL) {
if (p->p_profthreads != 0) {
while (p->p_profthreads != 0) {
p->p_flag |= P_STOPPROF;
msleep(&p->p_profthreads, &p->p_mtx, PPAUSE,
"stopprof", 0);
}
}
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 cnt, int usermode)
{
struct rusage *ru;
struct vmspace *vm;
struct thread *td;
struct proc *p;
long rss;
long *cp_time;
uint64_t runtime, new_switchtime;
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);
/*
* Compute the amount of time during which the current
* thread was running, and add that to its total so far.
*/
new_switchtime = cpu_ticks();
runtime = new_switchtime - PCPU_GET(switchtime);
td->td_runtime += runtime;
td->td_incruntime += runtime;
PCPU_SET(switchtime, new_switchtime);
sched_clock(td, cnt);
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 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
#ifdef HWPMC_HOOKS
if (td->td_intr_frame != NULL)
PMC_SOFT_CALL_TF( , , clock, prof, td->td_intr_frame);
#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");
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
}