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5b1a8eb397
freebsd-nq/sys/kern/kern_resource.c
Poul-Henning Kamp 5b1a8eb397 Modify the way we account for CPU time spent (step 1) 
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.

For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines.  (The main reason for this first milestone commit is
to verify that hypothesis.)

On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark.  On more modern hardware no change
in performance is seen.
2006-02-07 21:22:02 +00:00

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26 KiB
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/*-
* 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_resource.c 8.5 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/refcount.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/sx.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/time.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
#define UIHASH(uid) (&uihashtbl[(uid) & uihash])
static struct mtx uihashtbl_mtx;
static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
static u_long uihash; /* size of hash table - 1 */
static void calcru1(struct proc *p, struct rusage_ext *ruxp,
struct timeval *up, struct timeval *sp);
static int donice(struct thread *td, struct proc *chgp, int n);
static struct uidinfo *uilookup(uid_t uid);
/*
* Resource controls and accounting.
*/
#ifndef _SYS_SYSPROTO_H_
struct getpriority_args {
int which;
int who;
};
#endif
/*
* MPSAFE
*/
int
getpriority(td, uap)
struct thread *td;
register struct getpriority_args *uap;
{
struct proc *p;
struct pgrp *pg;
int error, low;
error = 0;
low = PRIO_MAX + 1;
switch (uap->which) {
case PRIO_PROCESS:
if (uap->who == 0)
low = td->td_proc->p_nice;
else {
p = pfind(uap->who);
if (p == NULL)
break;
if (p_cansee(td, p) == 0)
low = p->p_nice;
PROC_UNLOCK(p);
}
break;
case PRIO_PGRP:
sx_slock(&proctree_lock);
if (uap->who == 0) {
pg = td->td_proc->p_pgrp;
PGRP_LOCK(pg);
} else {
pg = pgfind(uap->who);
if (pg == NULL) {
sx_sunlock(&proctree_lock);
break;
}
}
sx_sunlock(&proctree_lock);
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (!p_cansee(td, p)) {
if (p->p_nice < low)
low = p->p_nice;
}
PROC_UNLOCK(p);
}
PGRP_UNLOCK(pg);
break;
case PRIO_USER:
if (uap->who == 0)
uap->who = td->td_ucred->cr_uid;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
PROC_LOCK(p);
if (!p_cansee(td, p) &&
p->p_ucred->cr_uid == uap->who) {
if (p->p_nice < low)
low = p->p_nice;
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
break;
default:
error = EINVAL;
break;
}
if (low == PRIO_MAX + 1 && error == 0)
error = ESRCH;
td->td_retval[0] = low;
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct setpriority_args {
int which;
int who;
int prio;
};
#endif
/*
* MPSAFE
*/
int
setpriority(td, uap)
struct thread *td;
struct setpriority_args *uap;
{
struct proc *curp, *p;
struct pgrp *pg;
int found = 0, error = 0;
curp = td->td_proc;
switch (uap->which) {
case PRIO_PROCESS:
if (uap->who == 0) {
PROC_LOCK(curp);
error = donice(td, curp, uap->prio);
PROC_UNLOCK(curp);
} else {
p = pfind(uap->who);
if (p == 0)
break;
if (p_cansee(td, p) == 0)
error = donice(td, p, uap->prio);
PROC_UNLOCK(p);
}
found++;
break;
case PRIO_PGRP:
sx_slock(&proctree_lock);
if (uap->who == 0) {
pg = curp->p_pgrp;
PGRP_LOCK(pg);
} else {
pg = pgfind(uap->who);
if (pg == NULL) {
sx_sunlock(&proctree_lock);
break;
}
}
sx_sunlock(&proctree_lock);
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (!p_cansee(td, p)) {
error = donice(td, p, uap->prio);
found++;
}
PROC_UNLOCK(p);
}
PGRP_UNLOCK(pg);
break;
case PRIO_USER:
if (uap->who == 0)
uap->who = td->td_ucred->cr_uid;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_ucred->cr_uid == uap->who &&
!p_cansee(td, p)) {
error = donice(td, p, uap->prio);
found++;
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
break;
default:
error = EINVAL;
break;
}
if (found == 0 && error == 0)
error = ESRCH;
return (error);
}
/*
* Set "nice" for a (whole) process.
*/
static int
donice(struct thread *td, struct proc *p, int n)
{
int error;
PROC_LOCK_ASSERT(p, MA_OWNED);
if ((error = p_cansched(td, p)))
return (error);
if (n > PRIO_MAX)
n = PRIO_MAX;
if (n < PRIO_MIN)
n = PRIO_MIN;
if (n < p->p_nice && suser(td) != 0)
return (EACCES);
mtx_lock_spin(&sched_lock);
sched_nice(p, n);
mtx_unlock_spin(&sched_lock);
return (0);
}
/*
* Set realtime priority.
*
* MPSAFE
*/
#ifndef _SYS_SYSPROTO_H_
struct rtprio_args {
int function;
pid_t pid;
struct rtprio *rtp;
};
#endif
int
rtprio(td, uap)
struct thread *td; /* curthread */
register struct rtprio_args *uap;
{
struct proc *curp;
struct proc *p;
struct ksegrp *kg;
struct rtprio rtp;
int cierror, error;
/* Perform copyin before acquiring locks if needed. */
if (uap->function == RTP_SET)
cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
else
cierror = 0;
curp = td->td_proc;
if (uap->pid == 0) {
p = curp;
PROC_LOCK(p);
} else {
p = pfind(uap->pid);
if (p == NULL)
return (ESRCH);
}
switch (uap->function) {
case RTP_LOOKUP:
if ((error = p_cansee(td, p)))
break;
mtx_lock_spin(&sched_lock);
/*
* Return OUR priority if no pid specified,
* or if one is, report the highest priority
* in the process. There isn't much more you can do as
* there is only room to return a single priority.
* XXXKSE: maybe need a new interface to report
* priorities of multiple system scope threads.
* Note: specifying our own pid is not the same
* as leaving it zero.
*/
if (uap->pid == 0) {
pri_to_rtp(td->td_ksegrp, &rtp);
} else {
struct rtprio rtp2;
rtp.type = RTP_PRIO_IDLE;
rtp.prio = RTP_PRIO_MAX;
FOREACH_KSEGRP_IN_PROC(p, kg) {
pri_to_rtp(kg, &rtp2);
if (rtp2.type < rtp.type ||
(rtp2.type == rtp.type &&
rtp2.prio < rtp.prio)) {
rtp.type = rtp2.type;
rtp.prio = rtp2.prio;
}
}
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
case RTP_SET:
if ((error = p_cansched(td, p)) || (error = cierror))
break;
/* Disallow setting rtprio in most cases if not superuser. */
if (suser(td) != 0) {
/* can't set someone else's */
if (uap->pid) {
error = EPERM;
break;
}
/* can't set realtime priority */
/*
* Realtime priority has to be restricted for reasons which should be
* obvious. However, for idle priority, there is a potential for
* system deadlock if an idleprio process gains a lock on a resource
* that other processes need (and the idleprio process can't run
* due to a CPU-bound normal process). Fix me! XXX
*/
#if 0
if (RTP_PRIO_IS_REALTIME(rtp.type)) {
#else
if (rtp.type != RTP_PRIO_NORMAL) {
#endif
error = EPERM;
break;
}
}
/*
* If we are setting our own priority, set just our
* KSEGRP but if we are doing another process,
* do all the groups on that process. If we
* specify our own pid we do the latter.
*/
mtx_lock_spin(&sched_lock);
if (uap->pid == 0) {
error = rtp_to_pri(&rtp, td->td_ksegrp);
} else {
FOREACH_KSEGRP_IN_PROC(p, kg) {
if ((error = rtp_to_pri(&rtp, kg)) != 0) {
break;
}
}
}
mtx_unlock_spin(&sched_lock);
break;
default:
error = EINVAL;
break;
}
PROC_UNLOCK(p);
return (error);
}
int
rtp_to_pri(struct rtprio *rtp, struct ksegrp *kg)
{
mtx_assert(&sched_lock, MA_OWNED);
if (rtp->prio > RTP_PRIO_MAX)
return (EINVAL);
switch (RTP_PRIO_BASE(rtp->type)) {
case RTP_PRIO_REALTIME:
kg->kg_user_pri = PRI_MIN_REALTIME + rtp->prio;
break;
case RTP_PRIO_NORMAL:
kg->kg_user_pri = PRI_MIN_TIMESHARE + rtp->prio;
break;
case RTP_PRIO_IDLE:
kg->kg_user_pri = PRI_MIN_IDLE + rtp->prio;
break;
default:
return (EINVAL);
}
sched_class(kg, rtp->type);
if (curthread->td_ksegrp == kg) {
sched_prio(curthread, kg->kg_user_pri); /* XXX dubious */
}
return (0);
}
void
pri_to_rtp(struct ksegrp *kg, struct rtprio *rtp)
{
mtx_assert(&sched_lock, MA_OWNED);
switch (PRI_BASE(kg->kg_pri_class)) {
case PRI_REALTIME:
rtp->prio = kg->kg_user_pri - PRI_MIN_REALTIME;
break;
case PRI_TIMESHARE:
rtp->prio = kg->kg_user_pri - PRI_MIN_TIMESHARE;
break;
case PRI_IDLE:
rtp->prio = kg->kg_user_pri - PRI_MIN_IDLE;
break;
default:
break;
}
rtp->type = kg->kg_pri_class;
}
#if defined(COMPAT_43)
#ifndef _SYS_SYSPROTO_H_
struct osetrlimit_args {
u_int which;
struct orlimit *rlp;
};
#endif
/*
* MPSAFE
*/
int
osetrlimit(td, uap)
struct thread *td;
register struct osetrlimit_args *uap;
{
struct orlimit olim;
struct rlimit lim;
int error;
if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
return (error);
lim.rlim_cur = olim.rlim_cur;
lim.rlim_max = olim.rlim_max;
error = kern_setrlimit(td, uap->which, &lim);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ogetrlimit_args {
u_int which;
struct orlimit *rlp;
};
#endif
/*
* MPSAFE
*/
int
ogetrlimit(td, uap)
struct thread *td;
register struct ogetrlimit_args *uap;
{
struct orlimit olim;
struct rlimit rl;
struct proc *p;
int error;
if (uap->which >= RLIM_NLIMITS)
return (EINVAL);
p = td->td_proc;
PROC_LOCK(p);
lim_rlimit(p, uap->which, &rl);
PROC_UNLOCK(p);
/*
* XXX would be more correct to convert only RLIM_INFINITY to the
* old RLIM_INFINITY and fail with EOVERFLOW for other larger
* values. Most 64->32 and 32->16 conversions, including not
* unimportant ones of uids are even more broken than what we
* do here (they blindly truncate). We don't do this correctly
* here since we have little experience with EOVERFLOW yet.
* Elsewhere, getuid() can't fail...
*/
olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
error = copyout(&olim, uap->rlp, sizeof(olim));
return (error);
}
#endif /* COMPAT_43 */
#ifndef _SYS_SYSPROTO_H_
struct __setrlimit_args {
u_int which;
struct rlimit *rlp;
};
#endif
/*
* MPSAFE
*/
int
setrlimit(td, uap)
struct thread *td;
register struct __setrlimit_args *uap;
{
struct rlimit alim;
int error;
if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
return (error);
error = kern_setrlimit(td, uap->which, &alim);
return (error);
}
int
kern_setrlimit(td, which, limp)
struct thread *td;
u_int which;
struct rlimit *limp;
{
struct plimit *newlim, *oldlim;
struct proc *p;
register struct rlimit *alimp;
rlim_t oldssiz;
int error;
if (which >= RLIM_NLIMITS)
return (EINVAL);
/*
* Preserve historical bugs by treating negative limits as unsigned.
*/
if (limp->rlim_cur < 0)
limp->rlim_cur = RLIM_INFINITY;
if (limp->rlim_max < 0)
limp->rlim_max = RLIM_INFINITY;
oldssiz = 0;
p = td->td_proc;
newlim = lim_alloc();
PROC_LOCK(p);
oldlim = p->p_limit;
alimp = &oldlim->pl_rlimit[which];
if (limp->rlim_cur > alimp->rlim_max ||
limp->rlim_max > alimp->rlim_max)
if ((error = suser_cred(td->td_ucred, SUSER_ALLOWJAIL))) {
PROC_UNLOCK(p);
lim_free(newlim);
return (error);
}
if (limp->rlim_cur > limp->rlim_max)
limp->rlim_cur = limp->rlim_max;
lim_copy(newlim, oldlim);
alimp = &newlim->pl_rlimit[which];
switch (which) {
case RLIMIT_CPU:
mtx_lock_spin(&sched_lock);
p->p_cpulimit = limp->rlim_cur;
mtx_unlock_spin(&sched_lock);
break;
case RLIMIT_DATA:
if (limp->rlim_cur > maxdsiz)
limp->rlim_cur = maxdsiz;
if (limp->rlim_max > maxdsiz)
limp->rlim_max = maxdsiz;
break;
case RLIMIT_STACK:
if (limp->rlim_cur > maxssiz)
limp->rlim_cur = maxssiz;
if (limp->rlim_max > maxssiz)
limp->rlim_max = maxssiz;
oldssiz = alimp->rlim_cur;
break;
case RLIMIT_NOFILE:
if (limp->rlim_cur > maxfilesperproc)
limp->rlim_cur = maxfilesperproc;
if (limp->rlim_max > maxfilesperproc)
limp->rlim_max = maxfilesperproc;
break;
case RLIMIT_NPROC:
if (limp->rlim_cur > maxprocperuid)
limp->rlim_cur = maxprocperuid;
if (limp->rlim_max > maxprocperuid)
limp->rlim_max = maxprocperuid;
if (limp->rlim_cur < 1)
limp->rlim_cur = 1;
if (limp->rlim_max < 1)
limp->rlim_max = 1;
break;
}
*alimp = *limp;
p->p_limit = newlim;
PROC_UNLOCK(p);
lim_free(oldlim);
if (which == RLIMIT_STACK) {
/*
* Stack is allocated to the max at exec time with only
* "rlim_cur" bytes accessible. If stack limit is going
* up make more accessible, if going down make inaccessible.
*/
if (limp->rlim_cur != oldssiz) {
vm_offset_t addr;
vm_size_t size;
vm_prot_t prot;
if (limp->rlim_cur > oldssiz) {
prot = p->p_sysent->sv_stackprot;
size = limp->rlim_cur - oldssiz;
addr = p->p_sysent->sv_usrstack -
limp->rlim_cur;
} else {
prot = VM_PROT_NONE;
size = oldssiz - limp->rlim_cur;
addr = p->p_sysent->sv_usrstack - oldssiz;
}
addr = trunc_page(addr);
size = round_page(size);
(void)vm_map_protect(&p->p_vmspace->vm_map,
addr, addr + size, prot, FALSE);
}
}
/*
* The data size limit may need to be changed to a value
* that makes sense for the 32 bit binary.
*/
if (p->p_sysent->sv_fixlimits != NULL)
p->p_sysent->sv_fixlimits(p);
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct __getrlimit_args {
u_int which;
struct rlimit *rlp;
};
#endif
/*
* MPSAFE
*/
/* ARGSUSED */
int
getrlimit(td, uap)
struct thread *td;
register struct __getrlimit_args *uap;
{
struct rlimit rlim;
struct proc *p;
int error;
if (uap->which >= RLIM_NLIMITS)
return (EINVAL);
p = td->td_proc;
PROC_LOCK(p);
lim_rlimit(p, uap->which, &rlim);
PROC_UNLOCK(p);
error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
return (error);
}
/*
* Transform the running time and tick information in proc p into user,
* system, and interrupt time usage.
*/
void
calcru(p, up, sp)
struct proc *p;
struct timeval *up;
struct timeval *sp;
{
uint64_t bt;
struct rusage_ext rux;
struct thread *td;
int bt_valid;
PROC_LOCK_ASSERT(p, MA_OWNED);
mtx_assert(&sched_lock, MA_NOTOWNED);
bt_valid = 0;
bt = 0;
mtx_lock_spin(&sched_lock);
rux = p->p_rux;
FOREACH_THREAD_IN_PROC(p, td) {
if (TD_IS_RUNNING(td)) {
/*
* Adjust for the current time slice. This is
* actually fairly important since the error here is
* on the order of a time quantum which is much
* greater than the precision of binuptime().
*/
KASSERT(td->td_oncpu != NOCPU,
("%s: running thread has no CPU", __func__));
if (!bt_valid) {
bt = cpu_ticks();
bt_valid = 1;
}
/*
* XXX: Doesn't this mean that this quantum will
* XXX: get counted twice if calcru() is called
* XXX: from SIGINFO ?
*/
rux.rux_runtime +=
(bt - pcpu_find(td->td_oncpu)->pc_switchtime);
}
}
mtx_unlock_spin(&sched_lock);
calcru1(p, &rux, up, sp);
p->p_rux.rux_uu = rux.rux_uu;
p->p_rux.rux_su = rux.rux_su;
p->p_rux.rux_iu = rux.rux_iu;
}
void
calccru(p, up, sp)
struct proc *p;
struct timeval *up;
struct timeval *sp;
{
PROC_LOCK_ASSERT(p, MA_OWNED);
calcru1(p, &p->p_crux, up, sp);
}
static void
calcru1(p, ruxp, up, sp)
struct proc *p;
struct rusage_ext *ruxp;
struct timeval *up;
struct timeval *sp;
{
/* {user, system, interrupt, total} {ticks, usec}; previous tu: */
u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
ut = ruxp->rux_uticks;
st = ruxp->rux_sticks;
it = ruxp->rux_iticks;
tt = ut + st + it;
if (tt == 0) {
st = 1;
tt = 1;
}
tu = (ruxp->rux_runtime * 1000000LL) / cpu_tickrate();
ptu = ruxp->rux_uu + ruxp->rux_su + ruxp->rux_iu;
if (tu < ptu) {
printf(
"calcru: runtime went backwards from %ju usec to %ju usec for pid %d (%s)\n",
(uintmax_t)ptu, (uintmax_t)tu, p->p_pid, p->p_comm);
tu = ptu;
}
if ((int64_t)tu < 0) {
printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
(intmax_t)tu, p->p_pid, p->p_comm);
tu = ptu;
}
/* Subdivide tu. */
uu = (tu * ut) / tt;
su = (tu * st) / tt;
iu = tu - uu - su;
/* Enforce monotonicity. */
if (uu < ruxp->rux_uu || su < ruxp->rux_su || iu < ruxp->rux_iu) {
if (uu < ruxp->rux_uu)
uu = ruxp->rux_uu;
else if (uu + ruxp->rux_su + ruxp->rux_iu > tu)
uu = tu - ruxp->rux_su - ruxp->rux_iu;
if (st == 0)
su = ruxp->rux_su;
else {
su = ((tu - uu) * st) / (st + it);
if (su < ruxp->rux_su)
su = ruxp->rux_su;
else if (uu + su + ruxp->rux_iu > tu)
su = tu - uu - ruxp->rux_iu;
}
KASSERT(uu + su + ruxp->rux_iu <= tu,
("calcru: monotonisation botch 1"));
iu = tu - uu - su;
KASSERT(iu >= ruxp->rux_iu,
("calcru: monotonisation botch 2"));
}
ruxp->rux_uu = uu;
ruxp->rux_su = su;
ruxp->rux_iu = iu;
up->tv_sec = uu / 1000000;
up->tv_usec = uu % 1000000;
sp->tv_sec = su / 1000000;
sp->tv_usec = su % 1000000;
}
#ifndef _SYS_SYSPROTO_H_
struct getrusage_args {
int who;
struct rusage *rusage;
};
#endif
/*
* MPSAFE
*/
int
getrusage(td, uap)
register struct thread *td;
register struct getrusage_args *uap;
{
struct rusage ru;
int error;
error = kern_getrusage(td, uap->who, &ru);
if (error == 0)
error = copyout(&ru, uap->rusage, sizeof(struct rusage));
return (error);
}
int
kern_getrusage(td, who, rup)
struct thread *td;
int who;
struct rusage *rup;
{
struct proc *p;
p = td->td_proc;
PROC_LOCK(p);
switch (who) {
case RUSAGE_SELF:
*rup = p->p_stats->p_ru;
calcru(p, &rup->ru_utime, &rup->ru_stime);
break;
case RUSAGE_CHILDREN:
*rup = p->p_stats->p_cru;
calccru(p, &rup->ru_utime, &rup->ru_stime);
break;
default:
PROC_UNLOCK(p);
return (EINVAL);
}
PROC_UNLOCK(p);
return (0);
}
void
ruadd(ru, rux, ru2, rux2)
struct rusage *ru;
struct rusage_ext *rux;
struct rusage *ru2;
struct rusage_ext *rux2;
{
register long *ip, *ip2;
register int i;
rux->rux_runtime += rux2->rux_runtime;
rux->rux_uticks += rux2->rux_uticks;
rux->rux_sticks += rux2->rux_sticks;
rux->rux_iticks += rux2->rux_iticks;
rux->rux_uu += rux2->rux_uu;
rux->rux_su += rux2->rux_su;
rux->rux_iu += rux2->rux_iu;
if (ru->ru_maxrss < ru2->ru_maxrss)
ru->ru_maxrss = ru2->ru_maxrss;
ip = &ru->ru_first;
ip2 = &ru2->ru_first;
for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
*ip++ += *ip2++;
}
/*
* Allocate a new resource limits structure and initialize its
* reference count and mutex pointer.
*/
struct plimit *
lim_alloc()
{
struct plimit *limp;
limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
refcount_init(&limp->pl_refcnt, 1);
return (limp);
}
struct plimit *
lim_hold(limp)
struct plimit *limp;
{
refcount_acquire(&limp->pl_refcnt);
return (limp);
}
void
lim_free(limp)
struct plimit *limp;
{
KASSERT(limp->pl_refcnt > 0, ("plimit refcnt underflow"));
if (refcount_release(&limp->pl_refcnt))
free((void *)limp, M_PLIMIT);
}
/*
* Make a copy of the plimit structure.
* We share these structures copy-on-write after fork.
*/
void
lim_copy(dst, src)
struct plimit *dst, *src;
{
KASSERT(dst->pl_refcnt == 1, ("lim_copy to shared limit"));
bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
}
/*
* Return the hard limit for a particular system resource. The
* which parameter specifies the index into the rlimit array.
*/
rlim_t
lim_max(struct proc *p, int which)
{
struct rlimit rl;
lim_rlimit(p, which, &rl);
return (rl.rlim_max);
}
/*
* Return the current (soft) limit for a particular system resource.
* The which parameter which specifies the index into the rlimit array
*/
rlim_t
lim_cur(struct proc *p, int which)
{
struct rlimit rl;
lim_rlimit(p, which, &rl);
return (rl.rlim_cur);
}
/*
* Return a copy of the entire rlimit structure for the system limit
* specified by 'which' in the rlimit structure pointed to by 'rlp'.
*/
void
lim_rlimit(struct proc *p, int which, struct rlimit *rlp)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
KASSERT(which >= 0 && which < RLIM_NLIMITS,
("request for invalid resource limit"));
*rlp = p->p_limit->pl_rlimit[which];
}
/*
* Find the uidinfo structure for a uid. This structure is used to
* track the total resource consumption (process count, socket buffer
* size, etc.) for the uid and impose limits.
*/
void
uihashinit()
{
uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
mtx_init(&uihashtbl_mtx, "uidinfo hash", NULL, MTX_DEF);
}
/*
* Look up a uidinfo struct for the parameter uid.
* uihashtbl_mtx must be locked.
*/
static struct uidinfo *
uilookup(uid)
uid_t uid;
{
struct uihashhead *uipp;
struct uidinfo *uip;
mtx_assert(&uihashtbl_mtx, MA_OWNED);
uipp = UIHASH(uid);
LIST_FOREACH(uip, uipp, ui_hash)
if (uip->ui_uid == uid)
break;
return (uip);
}
/*
* Find or allocate a struct uidinfo for a particular uid.
* Increase refcount on uidinfo struct returned.
* uifree() should be called on a struct uidinfo when released.
*/
struct uidinfo *
uifind(uid)
uid_t uid;
{
struct uidinfo *old_uip, *uip;
mtx_lock(&uihashtbl_mtx);
uip = uilookup(uid);
if (uip == NULL) {
mtx_unlock(&uihashtbl_mtx);
uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
mtx_lock(&uihashtbl_mtx);
/*
* There's a chance someone created our uidinfo while we
* were in malloc and not holding the lock, so we have to
* make sure we don't insert a duplicate uidinfo.
*/
if ((old_uip = uilookup(uid)) != NULL) {
/* Someone else beat us to it. */
free(uip, M_UIDINFO);
uip = old_uip;
} else {
uip->ui_mtxp = mtx_pool_alloc(mtxpool_sleep);
uip->ui_uid = uid;
LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
}
}
uihold(uip);
mtx_unlock(&uihashtbl_mtx);
return (uip);
}
/*
* Place another refcount on a uidinfo struct.
*/
void
uihold(uip)
struct uidinfo *uip;
{
UIDINFO_LOCK(uip);
uip->ui_ref++;
UIDINFO_UNLOCK(uip);
}
/*-
* Since uidinfo structs have a long lifetime, we use an
* opportunistic refcounting scheme to avoid locking the lookup hash
* for each release.
*
* If the refcount hits 0, we need to free the structure,
* which means we need to lock the hash.
* Optimal case:
* After locking the struct and lowering the refcount, if we find
* that we don't need to free, simply unlock and return.
* Suboptimal case:
* If refcount lowering results in need to free, bump the count
* back up, loose the lock and aquire the locks in the proper
* order to try again.
*/
void
uifree(uip)
struct uidinfo *uip;
{
/* Prepare for optimal case. */
UIDINFO_LOCK(uip);
if (--uip->ui_ref != 0) {
UIDINFO_UNLOCK(uip);
return;
}
/* Prepare for suboptimal case. */
uip->ui_ref++;
UIDINFO_UNLOCK(uip);
mtx_lock(&uihashtbl_mtx);
UIDINFO_LOCK(uip);
/*
* We must subtract one from the count again because we backed out
* our initial subtraction before dropping the lock.
* Since another thread may have added a reference after we dropped the
* initial lock we have to test for zero again.
*/
if (--uip->ui_ref == 0) {
LIST_REMOVE(uip, ui_hash);
mtx_unlock(&uihashtbl_mtx);
if (uip->ui_sbsize != 0)
printf("freeing uidinfo: uid = %d, sbsize = %jd\n",
uip->ui_uid, (intmax_t)uip->ui_sbsize);
if (uip->ui_proccnt != 0)
printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
uip->ui_uid, uip->ui_proccnt);
UIDINFO_UNLOCK(uip);
FREE(uip, M_UIDINFO);
return;
}
mtx_unlock(&uihashtbl_mtx);
UIDINFO_UNLOCK(uip);
}
/*
* Change the count associated with number of processes
* a given user is using. When 'max' is 0, don't enforce a limit
*/
int
chgproccnt(uip, diff, max)
struct uidinfo *uip;
int diff;
int max;
{
UIDINFO_LOCK(uip);
/* Don't allow them to exceed max, but allow subtraction. */
if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
UIDINFO_UNLOCK(uip);
return (0);
}
uip->ui_proccnt += diff;
if (uip->ui_proccnt < 0)
printf("negative proccnt for uid = %d\n", uip->ui_uid);
UIDINFO_UNLOCK(uip);
return (1);
}
/*
* Change the total socket buffer size a user has used.
*/
int
chgsbsize(uip, hiwat, to, max)
struct uidinfo *uip;
u_int *hiwat;
u_int to;
rlim_t max;
{
rlim_t new;
UIDINFO_LOCK(uip);
new = uip->ui_sbsize + to - *hiwat;
/* Don't allow them to exceed max, but allow subtraction. */
if (to > *hiwat && new > max) {
UIDINFO_UNLOCK(uip);
return (0);
}
uip->ui_sbsize = new;
UIDINFO_UNLOCK(uip);
*hiwat = to;
if (new < 0)
printf("negative sbsize for uid = %d\n", uip->ui_uid);
return (1);
}
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