/*-
* Copyright (c) 2000, 2004, 2006, 2007, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*-
* 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
*/
/*
* Clock handling routines.
*
* This code is written to operate with two timers that run independently of
* each other. The main clock, running hz times per second, is used to keep
* track of real time. 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.)
*/
int stathz;
int profhz;
int profsrc;
int schedhz;
int profprocs;
static int hardclock_ticks;
static int hardscheddiv; /* hard => sched divider (used if schedhz == 0) */
static int psdiv; /* prof => stat divider */
int psratio; /* ratio: prof / stat */
/* If there's nothing needed right now, stop here. */
if (__predict_true(atomic_load_relaxed(&C->needed) == 0))
return;
/*
* If we're not the primary core of a package, we're probably
* driven by the same clock as the primary core, so don't
* bother.
*/
if (ci != ci->ci_package1st)
return;
/* Take a sample and enter it into the pool. */
rnd_add_uint32(&C->source, 0);
/*
* On the primary CPU, count down. Using an atomic decrement
* here isn't really necessary -- on every platform we care
* about, stores to unsigned int are atomic, and the only other
* memory operation that could happen here is for another CPU
* to store a higher value for needed. But using an atomic
* decrement avoids giving the impression of data races, and is
* unlikely to hurt because only one CPU will ever be writing
* to the location.
*/
if (CPU_IS_PRIMARY(curcpu())) {
unsigned needed __diagused;
/*
* The real-time timer, interrupting hz times per second.
*/
void
hardclock(struct clockframe *frame)
{
struct lwp *l;
struct cpu_info *ci;
clockrnd_sample(&hardclockrnd);
ci = curcpu();
l = ci->ci_onproc;
ptimer_tick(l, CLKF_USERMODE(frame));
/*
* If no separate statistics clock is available, run it from here.
*/
if (stathz == 0)
statclock(frame);
/*
* If no separate schedclock is provided, call it here
* at about 16 Hz.
*/
if (schedhz == 0) {
if ((int)(--ci->ci_schedstate.spc_schedticks) <= 0) {
schedclock(l);
ci->ci_schedstate.spc_schedticks = hardscheddiv;
}
}
if ((--ci->ci_schedstate.spc_ticks) <= 0)
sched_tick(ci);
if (CPU_IS_PRIMARY(ci)) {
atomic_store_relaxed(&hardclock_ticks,
atomic_load_relaxed(&hardclock_ticks) + 1);
tc_ticktock();
}
/*
* Make sure the CPUs and timecounter are making progress.
*/
heartbeat();
/*
* 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)
{
KASSERT(mutex_owned(&p->p_stmutex));
if ((p->p_stflag & PST_PROFIL) == 0) {
p->p_stflag |= PST_PROFIL;
/*
* This is only necessary if using the clock as the
* profiling source.
*/
if (++profprocs == 1 && stathz != 0)
psdiv = psratio;
}
}
/*
* Stop profiling on a process.
*/
void
stopprofclock(struct proc *p)
{
KASSERT(mutex_owned(&p->p_stmutex));
if (p->p_stflag & PST_PROFIL) {
p->p_stflag &= ~PST_PROFIL;
/*
* This is only necessary if using the clock as the
* profiling source.
*/
if (--profprocs == 0 && stathz != 0)
psdiv = 1;
}
}
/*
* Statistics clock. Grab profile sample, and if divider reaches 0,
* do process and kernel statistics.
*/
void
statclock(struct clockframe *frame)
{
#ifdef GPROF
struct gmonparam *g;
intptr_t i;
#endif
struct cpu_info *ci = curcpu();
struct schedstate_percpu *spc = &ci->ci_schedstate;
struct proc *p;
struct lwp *l;
if (stathz)
clockrnd_sample(&statclockrnd);
/*
* Notice changes in divisor frequency, and adjust clock
* frequency accordingly.
*/
if (spc->spc_psdiv != psdiv) {
spc->spc_psdiv = psdiv;
spc->spc_pscnt = psdiv;
if (psdiv == 1) {
setstatclockrate(stathz);
} else {
setstatclockrate(profhz);
}
}
l = ci->ci_onproc;
if ((l->l_flag & LW_IDLE) != 0) {
/*
* don't account idle lwps as swapper.
*/
p = NULL;
} else {
p = l->l_proc;
mutex_spin_enter(&p->p_stmutex);
}
if (CLKF_USERMODE(frame)) {
KASSERT(p != NULL);
if ((p->p_stflag & PST_PROFIL) && profsrc == PROFSRC_CLOCK)
addupc_intr(l, CLKF_PC(frame));
if (--spc->spc_pscnt > 0) {
mutex_spin_exit(&p->p_stmutex);
return;
}
/*
* Came from user mode; CPU was in user state.
* If this process is being profiled record the tick.
*/
p->p_uticks++;
if (p->p_nice > NZERO)
spc->spc_cp_time[CP_NICE]++;
else
spc->spc_cp_time[CP_USER]++;
} else {
#ifdef GPROF
/*
* Kernel statistics are just like addupc_intr, only easier.
*/
#if defined(MULTIPROCESSOR) && !defined(_RUMPKERNEL)
g = curcpu()->ci_gmon;
if (g != NULL &&
profsrc == PROFSRC_CLOCK && g->state == GMON_PROF_ON) {
#else
g = &_gmonparam;
if (profsrc == PROFSRC_CLOCK && g->state == GMON_PROF_ON) {
#endif
i = CLKF_PC(frame) - g->lowpc;
if (i < g->textsize) {
i /= HISTFRACTION * sizeof(*g->kcount);
g->kcount[i]++;
}
}
#endif
#ifdef LWP_PC
if (p != NULL && profsrc == PROFSRC_CLOCK &&
(p->p_stflag & PST_PROFIL)) {
addupc_intr(l, LWP_PC(l));
}
#endif
if (--spc->spc_pscnt > 0) {
if (p != NULL)
mutex_spin_exit(&p->p_stmutex);
return;
}
/*
* 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 (CLKF_INTR(frame) || (curlwp->l_pflag & LP_INTR) != 0) {
if (p != NULL) {
p->p_iticks++;
}
spc->spc_cp_time[CP_INTR]++;
} else if (p != NULL) {
p->p_sticks++;
spc->spc_cp_time[CP_SYS]++;
} else {
spc->spc_cp_time[CP_IDLE]++;
}
}
spc->spc_pscnt = psdiv;
if (p != NULL) {
atomic_inc_uint(&l->l_cpticks);
mutex_spin_exit(&p->p_stmutex);
}
/*
* sysctl helper routine for kern.clockrate. Assembles a struct on
* the fly to be returned to the caller.
*/
static int
sysctl_kern_clockrate(SYSCTLFN_ARGS)
{
struct clockinfo clkinfo;
struct sysctlnode node;
