/*-
* 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_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/lock.h>
#include <sys/ktr.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/signalvar.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>
#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;
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,
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,
0,0, sysctl_kern_cp_times, "LU", "per-CPU time statistics");
void
read_cpu_time(long *cp_time)
{
struct pcpu *pc;
int i, j;
/* Sum up global cp_time[]. */
bzero(cp_time, sizeof(long) * CPUSTATES);
for (i = 0; i <= mp_maxid; i++) {
if (CPU_ABSENT(i))
continue;
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;
int ticks;
int psratio;
/*
* 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_SPIN);
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();
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);
#endif
}
/*
* The real-time timer, interrupting hz times per second.
*/
void
hardclock(int usermode, uintfptr_t pc)
{
int need_softclock = 0;
hardclock_cpu(usermode);
tc_ticktock();
/*
* 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 */
/*
* Process callouts at a very low cpu priority, so we don't keep the
* relatively high clock interrupt priority any longer than necessary.
*/
mtx_lock_spin_flags(&callout_lock, MTX_QUIET);
ticks++;
if (!TAILQ_EMPTY(&callwheel[ticks & callwheelmask])) {
need_softclock = 1;
} else if (softticks + 1 == ticks)
++softticks;
mtx_unlock_spin_flags(&callout_lock, MTX_QUIET);
/*
* swi_sched acquires the thread lock, so we don't want to call it
* with callout_lock held; incorrect locking order.
*/
if (need_softclock)
swi_sched(softclock_ih, 0);
#ifdef SW_WATCHDOG
if (watchdog_enabled > 0 && --watchdog_ticks <= 0)
watchdog_fire();
#endif /* SW_WATCHDOG */
}
/*
* 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_spin(&time_lock);
if (++profprocs == 1)
cpu_startprofclock();
mtx_unlock_spin(&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_spin(&time_lock);
if (--profprocs == 0)
cpu_stopprofclock();
mtx_unlock_spin(&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)
{
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.
*/
#ifdef KSE
if (p->p_flag & P_SA)
thread_statclock(1);
#endif
td->td_uticks++;
if (p->p_nice > NZERO)
cp_time[CP_NICE]++;
else
cp_time[CP_USER]++;
} 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++;
cp_time[CP_INTR]++;
} else {
#ifdef KSE
if (p->p_flag & P_SA)
thread_statclock(0);
#endif
td->td_pticks++;
td->td_sticks++;
if (!TD_IS_IDLETHREAD(td))
cp_time[CP_SYS]++;
else
cp_time[CP_IDLE]++;
}
}
/* 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);
ru->ru_idrss += pgtok(vm->vm_dsize);
ru->ru_isrss += pgtok(vm->vm_ssize);
rss = pgtok(vmspace_resident_count(vm));
if (ru->ru_maxrss < rss)
ru->ru_maxrss = rss;
CTR4(KTR_SCHED, "statclock: %p(%s) prio %d stathz %d",
td, td->td_name, td->td_priority, (stathz)?stathz:hz);
thread_lock_flags(td, MTX_QUIET);
sched_clock(td);
thread_unlock(td);
}
void
profclock(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, 1);
}
#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)++;
}
}
}
#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 panicking.
*/
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);
#if defined(KDB) && !defined(KDB_UNATTENDED)
kdb_backtrace();
kdb_enter(KDB_WHY_WATCHDOG, "watchdog timeout");
#else
panic("watchdog timeout");
#endif
}
#endif /* SW_WATCHDOG */
