Index: head/sys/kern/kern_resource.c =================================================================== --- head/sys/kern/kern_resource.c (revision 339186) +++ head/sys/kern/kern_resource.c (revision 339187) @@ -1,1452 +1,1449 @@ /*- * 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_resource.c 8.5 (Berkeley) 1/21/94 */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures"); static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures"); #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) static struct rwlock uihashtbl_lock; 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); static void ruxagg_locked(struct rusage_ext *rux, struct thread *td); /* * Resource controls and accounting. */ #ifndef _SYS_SYSPROTO_H_ struct getpriority_args { int which; int who; }; #endif int sys_getpriority(struct thread *td, 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->p_state == PRS_NORMAL && p_cansee(td, p) == 0) { 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); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NORMAL && p_cansee(td, p) == 0 && 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 int sys_setpriority(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 == NULL) break; error = p_cansee(td, p); if (error == 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->p_state == PRS_NORMAL && p_cansee(td, p) == 0) { 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_state == PRS_NORMAL && p->p_ucred->cr_uid == uap->who && p_cansee(td, p) == 0) { 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 && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0) return (EACCES); sched_nice(p, n); return (0); } static int unprivileged_idprio; SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW, &unprivileged_idprio, 0, "Allow non-root users to set an idle priority"); /* * Set realtime priority for LWP. */ #ifndef _SYS_SYSPROTO_H_ struct rtprio_thread_args { int function; lwpid_t lwpid; struct rtprio *rtp; }; #endif int sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap) { struct proc *p; struct rtprio rtp; struct thread *td1; 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; if (uap->lwpid == 0 || uap->lwpid == td->td_tid) { p = td->td_proc; td1 = td; PROC_LOCK(p); } else { /* Only look up thread in current process */ td1 = tdfind(uap->lwpid, curproc->p_pid); if (td1 == NULL) return (ESRCH); p = td1->td_proc; } switch (uap->function) { case RTP_LOOKUP: if ((error = p_cansee(td, p))) break; pri_to_rtp(td1, &rtp); 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. */ /* * Realtime priority has to be restricted for reasons which * should be obvious. However, for idleprio processes, 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 * * This problem is not only related to idleprio process. * A user level program can obtain a file lock and hold it * indefinitely. Additionally, without idleprio processes it is * still conceivable that a program with low priority will never * get to run. In short, allowing this feature might make it * easier to lock a resource indefinitely, but it is not the * only thing that makes it possible. */ if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME || (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE && unprivileged_idprio == 0)) { error = priv_check(td, PRIV_SCHED_RTPRIO); if (error) break; } error = rtp_to_pri(&rtp, td1); break; default: error = EINVAL; break; } PROC_UNLOCK(p); return (error); } /* * Set realtime priority. */ #ifndef _SYS_SYSPROTO_H_ struct rtprio_args { int function; pid_t pid; struct rtprio *rtp; }; #endif int sys_rtprio(struct thread *td, struct rtprio_args *uap) { struct proc *p; struct thread *tdp; 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; if (uap->pid == 0) { p = td->td_proc; 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; /* * 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. * Note: specifying our own pid is not the same * as leaving it zero. */ if (uap->pid == 0) { pri_to_rtp(td, &rtp); } else { struct rtprio rtp2; rtp.type = RTP_PRIO_IDLE; rtp.prio = RTP_PRIO_MAX; FOREACH_THREAD_IN_PROC(p, tdp) { pri_to_rtp(tdp, &rtp2); if (rtp2.type < rtp.type || (rtp2.type == rtp.type && rtp2.prio < rtp.prio)) { rtp.type = rtp2.type; rtp.prio = rtp2.prio; } } } 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. * See the comment in sys_rtprio_thread about idprio * threads holding a lock. */ if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME || (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE && !unprivileged_idprio)) { error = priv_check(td, PRIV_SCHED_RTPRIO); if (error) break; } /* * If we are setting our own priority, set just our * thread but if we are doing another process, * do all the threads on that process. If we * specify our own pid we do the latter. */ if (uap->pid == 0) { error = rtp_to_pri(&rtp, td); } else { FOREACH_THREAD_IN_PROC(p, td) { if ((error = rtp_to_pri(&rtp, td)) != 0) break; } } break; default: error = EINVAL; break; } PROC_UNLOCK(p); return (error); } int rtp_to_pri(struct rtprio *rtp, struct thread *td) { u_char newpri, oldclass, oldpri; switch (RTP_PRIO_BASE(rtp->type)) { case RTP_PRIO_REALTIME: if (rtp->prio > RTP_PRIO_MAX) return (EINVAL); newpri = PRI_MIN_REALTIME + rtp->prio; break; case RTP_PRIO_NORMAL: if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) return (EINVAL); newpri = PRI_MIN_TIMESHARE + rtp->prio; break; case RTP_PRIO_IDLE: if (rtp->prio > RTP_PRIO_MAX) return (EINVAL); newpri = PRI_MIN_IDLE + rtp->prio; break; default: return (EINVAL); } thread_lock(td); oldclass = td->td_pri_class; sched_class(td, rtp->type); /* XXX fix */ oldpri = td->td_user_pri; sched_user_prio(td, newpri); if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL || td->td_pri_class != RTP_PRIO_NORMAL)) sched_prio(td, td->td_user_pri); if (TD_ON_UPILOCK(td) && oldpri != newpri) { critical_enter(); thread_unlock(td); umtx_pi_adjust(td, oldpri); critical_exit(); } else thread_unlock(td); return (0); } void pri_to_rtp(struct thread *td, struct rtprio *rtp) { thread_lock(td); switch (PRI_BASE(td->td_pri_class)) { case PRI_REALTIME: rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME; break; case PRI_TIMESHARE: rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE; break; case PRI_IDLE: rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE; break; default: break; } rtp->type = td->td_pri_class; thread_unlock(td); } #if defined(COMPAT_43) #ifndef _SYS_SYSPROTO_H_ struct osetrlimit_args { u_int which; struct orlimit *rlp; }; #endif int osetrlimit(struct thread *td, 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 int ogetrlimit(struct thread *td, struct ogetrlimit_args *uap) { struct orlimit olim; struct rlimit rl; int error; if (uap->which >= RLIM_NLIMITS) return (EINVAL); lim_rlimit(td, uap->which, &rl); /* * 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 int sys_setrlimit(struct thread *td, 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); } static void lim_cb(void *arg) { struct rlimit rlim; struct thread *td; struct proc *p; p = arg; PROC_LOCK_ASSERT(p, MA_OWNED); /* * Check if the process exceeds its cpu resource allocation. If * it reaches the max, arrange to kill the process in ast(). */ if (p->p_cpulimit == RLIM_INFINITY) return; PROC_STATLOCK(p); FOREACH_THREAD_IN_PROC(p, td) { ruxagg(p, td); } PROC_STATUNLOCK(p); if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) { lim_rlimit_proc(p, RLIMIT_CPU, &rlim); if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) { killproc(p, "exceeded maximum CPU limit"); } else { if (p->p_cpulimit < rlim.rlim_max) p->p_cpulimit += 5; kern_psignal(p, SIGXCPU); } } if ((p->p_flag & P_WEXIT) == 0) callout_reset_sbt(&p->p_limco, SBT_1S, 0, lim_cb, p, C_PREL(1)); } int kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp) { return (kern_proc_setrlimit(td, td->td_proc, which, limp)); } int kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which, struct rlimit *limp) { struct plimit *newlim, *oldlim; struct rlimit *alimp; struct rlimit 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.rlim_cur = 0; 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 = priv_check(td, PRIV_PROC_SETRLIMIT))) { 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: if (limp->rlim_cur != RLIM_INFINITY && p->p_cpulimit == RLIM_INFINITY) callout_reset_sbt(&p->p_limco, SBT_1S, 0, lim_cb, p, C_PREL(1)); p->p_cpulimit = limp->rlim_cur; 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; if (p->p_sysent->sv_fixlimit != NULL) p->p_sysent->sv_fixlimit(&oldssiz, RLIMIT_STACK); 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; } if (p->p_sysent->sv_fixlimit != NULL) p->p_sysent->sv_fixlimit(limp, which); *alimp = *limp; p->p_limit = newlim; PROC_UPDATE_COW(p); PROC_UNLOCK(p); lim_free(oldlim); if (which == RLIMIT_STACK && /* * Skip calls from exec_new_vmspace(), done when stack is * not mapped yet. */ (td != curthread || (p->p_flag & P_INEXEC) == 0)) { /* * 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.rlim_cur) { vm_offset_t addr; vm_size_t size; vm_prot_t prot; if (limp->rlim_cur > oldssiz.rlim_cur) { prot = p->p_sysent->sv_stackprot; size = limp->rlim_cur - oldssiz.rlim_cur; addr = p->p_sysent->sv_usrstack - limp->rlim_cur; } else { prot = VM_PROT_NONE; size = oldssiz.rlim_cur - limp->rlim_cur; addr = p->p_sysent->sv_usrstack - oldssiz.rlim_cur; } addr = trunc_page(addr); size = round_page(size); (void)vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot, FALSE); } } return (0); } #ifndef _SYS_SYSPROTO_H_ struct __getrlimit_args { u_int which; struct rlimit *rlp; }; #endif /* ARGSUSED */ int sys_getrlimit(struct thread *td, struct __getrlimit_args *uap) { struct rlimit rlim; int error; if (uap->which >= RLIM_NLIMITS) return (EINVAL); lim_rlimit(td, uap->which, &rlim); error = copyout(&rlim, uap->rlp, sizeof(struct rlimit)); return (error); } /* * Transform the running time and tick information for children of proc p * into user and system time usage. */ void calccru(struct proc *p, struct timeval *up, struct timeval *sp) { PROC_LOCK_ASSERT(p, MA_OWNED); calcru1(p, &p->p_crux, up, sp); } /* * Transform the running time and tick information in proc p into user * and system time usage. If appropriate, include the current time slice * on this CPU. */ void calcru(struct proc *p, struct timeval *up, struct timeval *sp) { struct thread *td; uint64_t runtime, u; PROC_LOCK_ASSERT(p, MA_OWNED); PROC_STATLOCK_ASSERT(p, MA_OWNED); /* * If we are getting stats for the current process, then add in the * stats that this thread has accumulated in its current time slice. * We reset the thread and CPU state as if we had performed a context * switch right here. */ td = curthread; if (td->td_proc == p) { u = cpu_ticks(); runtime = u - PCPU_GET(switchtime); td->td_runtime += runtime; td->td_incruntime += runtime; PCPU_SET(switchtime, u); } /* Make sure the per-thread stats are current. */ FOREACH_THREAD_IN_PROC(p, td) { if (td->td_incruntime == 0) continue; ruxagg(p, td); } calcru1(p, &p->p_rux, up, sp); } /* Collect resource usage for a single thread. */ void rufetchtd(struct thread *td, struct rusage *ru) { struct proc *p; uint64_t runtime, u; p = td->td_proc; PROC_STATLOCK_ASSERT(p, MA_OWNED); THREAD_LOCK_ASSERT(td, MA_OWNED); /* * If we are getting stats for the current thread, then add in the * stats that this thread has accumulated in its current time slice. * We reset the thread and CPU state as if we had performed a context * switch right here. */ if (td == curthread) { u = cpu_ticks(); runtime = u - PCPU_GET(switchtime); td->td_runtime += runtime; td->td_incruntime += runtime; PCPU_SET(switchtime, u); } ruxagg(p, td); *ru = td->td_ru; calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime); } static void calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up, struct timeval *sp) { /* {user, system, interrupt, total} {ticks, usec}: */ uint64_t ut, uu, st, su, it, tt, tu; ut = ruxp->rux_uticks; st = ruxp->rux_sticks; it = ruxp->rux_iticks; tt = ut + st + it; if (tt == 0) { /* Avoid divide by zero */ st = 1; tt = 1; } tu = cputick2usec(ruxp->rux_runtime); if ((int64_t)tu < 0) { /* XXX: this should be an assert /phk */ printf("calcru: negative runtime of %jd usec for pid %d (%s)\n", (intmax_t)tu, p->p_pid, p->p_comm); tu = ruxp->rux_tu; } if (tu >= ruxp->rux_tu) { /* * The normal case, time increased. * Enforce monotonicity of bucketed numbers. */ uu = (tu * ut) / tt; if (uu < ruxp->rux_uu) uu = ruxp->rux_uu; su = (tu * st) / tt; if (su < ruxp->rux_su) su = ruxp->rux_su; } else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) { /* * When we calibrate the cputicker, it is not uncommon to * see the presumably fixed frequency increase slightly over * time as a result of thermal stabilization and NTP * discipline (of the reference clock). We therefore ignore * a bit of backwards slop because we expect to catch up * shortly. We use a 3 microsecond limit to catch low * counts and a 1% limit for high counts. */ uu = ruxp->rux_uu; su = ruxp->rux_su; tu = ruxp->rux_tu; } else { /* tu < ruxp->rux_tu */ /* * What happened here was likely that a laptop, which ran at * a reduced clock frequency at boot, kicked into high gear. * The wisdom of spamming this message in that case is * dubious, but it might also be indicative of something * serious, so lets keep it and hope laptops can be made * more truthful about their CPU speed via ACPI. */ printf("calcru: runtime went backwards from %ju usec " "to %ju usec for pid %d (%s)\n", (uintmax_t)ruxp->rux_tu, (uintmax_t)tu, p->p_pid, p->p_comm); uu = (tu * ut) / tt; su = (tu * st) / tt; } ruxp->rux_uu = uu; ruxp->rux_su = su; ruxp->rux_tu = tu; 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 int sys_getrusage(struct thread *td, 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(struct thread *td, int who, struct rusage *rup) { struct proc *p; int error; error = 0; p = td->td_proc; PROC_LOCK(p); switch (who) { case RUSAGE_SELF: rufetchcalc(p, rup, &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; case RUSAGE_THREAD: PROC_STATLOCK(p); thread_lock(td); rufetchtd(td, rup); thread_unlock(td); PROC_STATUNLOCK(p); break; default: error = EINVAL; } PROC_UNLOCK(p); return (error); } void rucollect(struct rusage *ru, struct rusage *ru2) { long *ip, *ip2; int i; 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++; } void ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2, struct rusage_ext *rux2) { 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_tu += rux2->rux_tu; rucollect(ru, ru2); } /* * Aggregate tick counts into the proc's rusage_ext. */ static void ruxagg_locked(struct rusage_ext *rux, struct thread *td) { THREAD_LOCK_ASSERT(td, MA_OWNED); PROC_STATLOCK_ASSERT(td->td_proc, MA_OWNED); rux->rux_runtime += td->td_incruntime; rux->rux_uticks += td->td_uticks; rux->rux_sticks += td->td_sticks; rux->rux_iticks += td->td_iticks; } void ruxagg(struct proc *p, struct thread *td) { thread_lock(td); ruxagg_locked(&p->p_rux, td); ruxagg_locked(&td->td_rux, td); td->td_incruntime = 0; td->td_uticks = 0; td->td_iticks = 0; td->td_sticks = 0; thread_unlock(td); } /* * Update the rusage_ext structure and fetch a valid aggregate rusage * for proc p if storage for one is supplied. */ void rufetch(struct proc *p, struct rusage *ru) { struct thread *td; PROC_STATLOCK_ASSERT(p, MA_OWNED); *ru = p->p_ru; if (p->p_numthreads > 0) { FOREACH_THREAD_IN_PROC(p, td) { ruxagg(p, td); rucollect(ru, &td->td_ru); } } } /* * Atomically perform a rufetch and a calcru together. * Consumers, can safely assume the calcru is executed only once * rufetch is completed. */ void rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up, struct timeval *sp) { PROC_STATLOCK(p); rufetch(p, ru); calcru(p, up, sp); PROC_STATUNLOCK(p); } /* * 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(struct plimit *limp) { refcount_acquire(&limp->pl_refcnt); return (limp); } void lim_fork(struct proc *p1, struct proc *p2) { PROC_LOCK_ASSERT(p1, MA_OWNED); PROC_LOCK_ASSERT(p2, MA_OWNED); p2->p_limit = lim_hold(p1->p_limit); callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0); if (p1->p_cpulimit != RLIM_INFINITY) callout_reset_sbt(&p2->p_limco, SBT_1S, 0, lim_cb, p2, C_PREL(1)); } void lim_free(struct plimit *limp) { 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(struct plimit *dst, struct plimit *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 thread *td, int which) { struct rlimit rl; lim_rlimit(td, which, &rl); return (rl.rlim_max); } rlim_t lim_max_proc(struct proc *p, int which) { struct rlimit rl; lim_rlimit_proc(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 thread *td, int which) { struct rlimit rl; lim_rlimit(td, which, &rl); return (rl.rlim_cur); } rlim_t lim_cur_proc(struct proc *p, int which) { struct rlimit rl; lim_rlimit_proc(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 thread *td, int which, struct rlimit *rlp) { struct proc *p = td->td_proc; MPASS(td == curthread); KASSERT(which >= 0 && which < RLIM_NLIMITS, ("request for invalid resource limit")); *rlp = td->td_limit->pl_rlimit[which]; if (p->p_sysent->sv_fixlimit != NULL) p->p_sysent->sv_fixlimit(rlp, which); } void lim_rlimit_proc(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]; if (p->p_sysent->sv_fixlimit != NULL) p->p_sysent->sv_fixlimit(rlp, which); } void uihashinit() { uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash); rw_init(&uihashtbl_lock, "uidinfo hash"); } /* * Look up a uidinfo struct for the parameter uid. * uihashtbl_lock must be locked. * Increase refcount on uidinfo struct returned. */ static struct uidinfo * uilookup(uid_t uid) { struct uihashhead *uipp; struct uidinfo *uip; rw_assert(&uihashtbl_lock, RA_LOCKED); uipp = UIHASH(uid); LIST_FOREACH(uip, uipp, ui_hash) if (uip->ui_uid == uid) { uihold(uip); break; } return (uip); } /* * Find or allocate a struct uidinfo for a particular uid. * Returns with uidinfo struct referenced. * uifree() should be called on a struct uidinfo when released. */ struct uidinfo * uifind(uid_t uid) { struct uidinfo *new_uip, *uip; struct ucred *cred; cred = curthread->td_ucred; if (cred->cr_uidinfo->ui_uid == uid) { uip = cred->cr_uidinfo; uihold(uip); return (uip); } else if (cred->cr_ruidinfo->ui_uid == uid) { uip = cred->cr_ruidinfo; uihold(uip); return (uip); } rw_rlock(&uihashtbl_lock); uip = uilookup(uid); rw_runlock(&uihashtbl_lock); if (uip != NULL) return (uip); new_uip = malloc(sizeof(*new_uip), M_UIDINFO, M_WAITOK | M_ZERO); racct_create(&new_uip->ui_racct); refcount_init(&new_uip->ui_ref, 1); new_uip->ui_uid = uid; - mtx_init(&new_uip->ui_vmsize_mtx, "ui_vmsize", NULL, MTX_DEF); rw_wlock(&uihashtbl_lock); /* * 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 ((uip = uilookup(uid)) == NULL) { LIST_INSERT_HEAD(UIHASH(uid), new_uip, ui_hash); rw_wunlock(&uihashtbl_lock); uip = new_uip; } else { rw_wunlock(&uihashtbl_lock); racct_destroy(&new_uip->ui_racct); - mtx_destroy(&new_uip->ui_vmsize_mtx); free(new_uip, M_UIDINFO); } return (uip); } /* * Place another refcount on a uidinfo struct. */ void uihold(struct uidinfo *uip) { refcount_acquire(&uip->ui_ref); } /*- * 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, lose the lock and acquire the locks in the proper * order to try again. */ void uifree(struct uidinfo *uip) { int old; /* Prepare for optimal case. */ old = uip->ui_ref; if (old > 1 && atomic_cmpset_int(&uip->ui_ref, old, old - 1)) return; /* Prepare for suboptimal case. */ rw_wlock(&uihashtbl_lock); if (refcount_release(&uip->ui_ref) == 0) { rw_wunlock(&uihashtbl_lock); return; } racct_destroy(&uip->ui_racct); LIST_REMOVE(uip, ui_hash); rw_wunlock(&uihashtbl_lock); if (uip->ui_sbsize != 0) printf("freeing uidinfo: uid = %d, sbsize = %ld\n", uip->ui_uid, uip->ui_sbsize); if (uip->ui_proccnt != 0) printf("freeing uidinfo: uid = %d, proccnt = %ld\n", uip->ui_uid, uip->ui_proccnt); if (uip->ui_vmsize != 0) printf("freeing uidinfo: uid = %d, swapuse = %lld\n", uip->ui_uid, (unsigned long long)uip->ui_vmsize); - mtx_destroy(&uip->ui_vmsize_mtx); free(uip, M_UIDINFO); } #ifdef RACCT void ui_racct_foreach(void (*callback)(struct racct *racct, void *arg2, void *arg3), void (*pre)(void), void (*post)(void), void *arg2, void *arg3) { struct uidinfo *uip; struct uihashhead *uih; rw_rlock(&uihashtbl_lock); if (pre != NULL) (pre)(); for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) { LIST_FOREACH(uip, uih, ui_hash) { (callback)(uip->ui_racct, arg2, arg3); } } if (post != NULL) (post)(); rw_runlock(&uihashtbl_lock); } #endif static inline int chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char *name) { long new; /* Don't allow them to exceed max, but allow subtraction. */ new = atomic_fetchadd_long(limit, (long)diff) + diff; if (diff > 0 && max != 0) { if (new < 0 || new > max) { atomic_subtract_long(limit, (long)diff); return (0); } } else if (new < 0) printf("negative %s for uid = %d\n", name, uip->ui_uid); return (1); } /* * Change the count associated with number of processes * a given user is using. When 'max' is 0, don't enforce a limit */ int chgproccnt(struct uidinfo *uip, int diff, rlim_t max) { return (chglimit(uip, &uip->ui_proccnt, diff, max, "proccnt")); } /* * Change the total socket buffer size a user has used. */ int chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t max) { int diff, rv; diff = to - *hiwat; if (diff > 0 && max == 0) { rv = 0; } else { rv = chglimit(uip, &uip->ui_sbsize, diff, max, "sbsize"); if (rv != 0) *hiwat = to; } return (rv); } /* * Change the count associated with number of pseudo-terminals * a given user is using. When 'max' is 0, don't enforce a limit */ int chgptscnt(struct uidinfo *uip, int diff, rlim_t max) { return (chglimit(uip, &uip->ui_ptscnt, diff, max, "ptscnt")); } int chgkqcnt(struct uidinfo *uip, int diff, rlim_t max) { return (chglimit(uip, &uip->ui_kqcnt, diff, max, "kqcnt")); } int chgumtxcnt(struct uidinfo *uip, int diff, rlim_t max) { return (chglimit(uip, &uip->ui_umtxcnt, diff, max, "umtxcnt")); } Index: head/sys/sys/resourcevar.h =================================================================== --- head/sys/sys/resourcevar.h (revision 339186) +++ head/sys/sys/resourcevar.h (revision 339187) @@ -1,166 +1,164 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * 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. * * @(#)resourcevar.h 8.4 (Berkeley) 1/9/95 * $FreeBSD$ */ #ifndef _SYS_RESOURCEVAR_H_ #define _SYS_RESOURCEVAR_H_ #include #include #ifdef _KERNEL #include #include #endif /* * Kernel per-process accounting / statistics * (not necessarily resident except when running). * * Locking key: * b - created at fork, never changes * c - locked by proc mtx * k - only accessed by curthread * w - locked by proc itim lock * w2 - locked by proc prof lock */ struct pstats { #define pstat_startzero p_cru struct rusage p_cru; /* Stats for reaped children. */ struct itimerval p_timer[3]; /* (w) Virtual-time timers. */ #define pstat_endzero pstat_startcopy #define pstat_startcopy p_prof struct uprof { /* Profile arguments. */ caddr_t pr_base; /* (c + w2) Buffer base. */ u_long pr_size; /* (c + w2) Buffer size. */ u_long pr_off; /* (c + w2) PC offset. */ u_long pr_scale; /* (c + w2) PC scaling. */ } p_prof; #define pstat_endcopy p_start struct timeval p_start; /* (b) Starting time. */ }; #ifdef _KERNEL /* * Kernel shareable process resource limits. Because this structure * is moderately large but changes infrequently, it is normally * shared copy-on-write after forks. */ struct plimit { struct rlimit pl_rlimit[RLIM_NLIMITS]; int pl_refcnt; /* number of references */ }; struct racct; /*- * Per uid resource consumption. This structure is used to track * the total resource consumption (process count, socket buffer size, * etc) for the uid and impose limits. * * Locking guide: * (a) Constant from inception * (b) Lockless, updated using atomics * (c) Locked by global uihashtbl_lock - * (d) Locked by the ui_vmsize_mtx */ struct uidinfo { LIST_ENTRY(uidinfo) ui_hash; /* (c) hash chain of uidinfos */ - struct mtx ui_vmsize_mtx; - vm_ooffset_t ui_vmsize; /* (d) swap reservation by uid */ + u_long ui_vmsize; /* (b) pages of swap reservation by uid */ long ui_sbsize; /* (b) socket buffer space consumed */ long ui_proccnt; /* (b) number of processes */ long ui_ptscnt; /* (b) number of pseudo-terminals */ long ui_kqcnt; /* (b) number of kqueues */ long ui_umtxcnt; /* (b) number of shared umtxs */ uid_t ui_uid; /* (a) uid */ u_int ui_ref; /* (b) reference count */ #ifdef RACCT struct racct *ui_racct; /* (a) resource accounting */ #endif }; #define UIDINFO_VMSIZE_LOCK(ui) mtx_lock(&((ui)->ui_vmsize_mtx)) #define UIDINFO_VMSIZE_UNLOCK(ui) mtx_unlock(&((ui)->ui_vmsize_mtx)) struct proc; struct rusage_ext; struct thread; void addupc_intr(struct thread *td, uintfptr_t pc, u_int ticks); void addupc_task(struct thread *td, uintfptr_t pc, u_int ticks); void calccru(struct proc *p, struct timeval *up, struct timeval *sp); void calcru(struct proc *p, struct timeval *up, struct timeval *sp); int chgkqcnt(struct uidinfo *uip, int diff, rlim_t max); int chgproccnt(struct uidinfo *uip, int diff, rlim_t maxval); int chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t maxval); int chgptscnt(struct uidinfo *uip, int diff, rlim_t maxval); int chgumtxcnt(struct uidinfo *uip, int diff, rlim_t maxval); int kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which, struct rlimit *limp); struct plimit *lim_alloc(void); void lim_copy(struct plimit *dst, struct plimit *src); rlim_t lim_cur(struct thread *td, int which); rlim_t lim_cur_proc(struct proc *p, int which); void lim_fork(struct proc *p1, struct proc *p2); void lim_free(struct plimit *limp); struct plimit *lim_hold(struct plimit *limp); rlim_t lim_max(struct thread *td, int which); rlim_t lim_max_proc(struct proc *p, int which); void lim_rlimit(struct thread *td, int which, struct rlimit *rlp); void lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp); void ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2, struct rusage_ext *rux2); void rucollect(struct rusage *ru, struct rusage *ru2); void rufetch(struct proc *p, struct rusage *ru); void rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up, struct timeval *sp); void rufetchtd(struct thread *td, struct rusage *ru); void ruxagg(struct proc *p, struct thread *td); struct uidinfo *uifind(uid_t uid); void uifree(struct uidinfo *uip); void uihashinit(void); void uihold(struct uidinfo *uip); #ifdef RACCT void ui_racct_foreach(void (*callback)(struct racct *racct, void *arg2, void *arg3), void (*pre)(void), void (*post)(void), void *arg2, void *arg3); #endif #endif /* _KERNEL */ #endif /* !_SYS_RESOURCEVAR_H_ */ Index: head/sys/vm/swap_pager.c =================================================================== --- head/sys/vm/swap_pager.c (revision 339186) +++ head/sys/vm/swap_pager.c (revision 339187) @@ -1,2896 +1,2905 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (c) 1998 Matthew Dillon, * Copyright (c) 1994 John S. Dyson * Copyright (c) 1990 University of Utah. * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 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. * * New Swap System * Matthew Dillon * * Radix Bitmap 'blists'. * * - The new swapper uses the new radix bitmap code. This should scale * to arbitrarily small or arbitrarily large swap spaces and an almost * arbitrary degree of fragmentation. * * Features: * * - on the fly reallocation of swap during putpages. The new system * does not try to keep previously allocated swap blocks for dirty * pages. * * - on the fly deallocation of swap * * - No more garbage collection required. Unnecessarily allocated swap * blocks only exist for dirty vm_page_t's now and these are already * cycled (in a high-load system) by the pager. We also do on-the-fly * removal of invalidated swap blocks when a page is destroyed * or renamed. * * from: Utah $Hdr: swap_pager.c 1.4 91/04/30$ * * @(#)swap_pager.c 8.9 (Berkeley) 3/21/94 * @(#)vm_swap.c 8.5 (Berkeley) 2/17/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_swap.h" #include "opt_vm.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * MAX_PAGEOUT_CLUSTER must be a power of 2 between 1 and 64. * The 64-page limit is due to the radix code (kern/subr_blist.c). */ #ifndef MAX_PAGEOUT_CLUSTER #define MAX_PAGEOUT_CLUSTER 32 #endif #if !defined(SWB_NPAGES) #define SWB_NPAGES MAX_PAGEOUT_CLUSTER #endif #define SWAP_META_PAGES PCTRIE_COUNT /* * A swblk structure maps each page index within a * SWAP_META_PAGES-aligned and sized range to the address of an * on-disk swap block (or SWAPBLK_NONE). The collection of these * mappings for an entire vm object is implemented as a pc-trie. */ struct swblk { vm_pindex_t p; daddr_t d[SWAP_META_PAGES]; }; static MALLOC_DEFINE(M_VMPGDATA, "vm_pgdata", "swap pager private data"); static struct mtx sw_dev_mtx; static TAILQ_HEAD(, swdevt) swtailq = TAILQ_HEAD_INITIALIZER(swtailq); static struct swdevt *swdevhd; /* Allocate from here next */ static int nswapdev; /* Number of swap devices */ int swap_pager_avail; static struct sx swdev_syscall_lock; /* serialize swap(on|off) */ -static vm_ooffset_t swap_total; -SYSCTL_QUAD(_vm, OID_AUTO, swap_total, CTLFLAG_RD, &swap_total, 0, - "Total amount of available swap storage."); -static vm_ooffset_t swap_reserved; -SYSCTL_QUAD(_vm, OID_AUTO, swap_reserved, CTLFLAG_RD, &swap_reserved, 0, +static u_long swap_reserved; +static u_long swap_total; +static int sysctl_page_shift(SYSCTL_HANDLER_ARGS); +SYSCTL_PROC(_vm, OID_AUTO, swap_reserved, CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE, + &swap_reserved, 0, sysctl_page_shift, "A", "Amount of swap storage needed to back all allocated anonymous memory."); +SYSCTL_PROC(_vm, OID_AUTO, swap_total, CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE, + &swap_total, 0, sysctl_page_shift, "A", + "Total amount of available swap storage."); + static int overcommit = 0; SYSCTL_INT(_vm, VM_OVERCOMMIT, overcommit, CTLFLAG_RW, &overcommit, 0, "Configure virtual memory overcommit behavior. See tuning(7) " "for details."); static unsigned long swzone; SYSCTL_ULONG(_vm, OID_AUTO, swzone, CTLFLAG_RD, &swzone, 0, "Actual size of swap metadata zone"); static unsigned long swap_maxpages; SYSCTL_ULONG(_vm, OID_AUTO, swap_maxpages, CTLFLAG_RD, &swap_maxpages, 0, "Maximum amount of swap supported"); /* bits from overcommit */ #define SWAP_RESERVE_FORCE_ON (1 << 0) #define SWAP_RESERVE_RLIMIT_ON (1 << 1) #define SWAP_RESERVE_ALLOW_NONWIRED (1 << 2) +static int +sysctl_page_shift(SYSCTL_HANDLER_ARGS) +{ + uint64_t newval; + u_long value = *(u_long *)arg1; + + newval = ((uint64_t)value) << PAGE_SHIFT; + return (sysctl_handle_64(oidp, &newval, 0, req)); +} + int swap_reserve(vm_ooffset_t incr) { return (swap_reserve_by_cred(incr, curthread->td_ucred)); } int swap_reserve_by_cred(vm_ooffset_t incr, struct ucred *cred) { - vm_ooffset_t r, s; + u_long r, s, prev, pincr; int res, error; static int curfail; static struct timeval lastfail; struct uidinfo *uip; uip = cred->cr_ruidinfo; - if (incr & PAGE_MASK) - panic("swap_reserve: & PAGE_MASK"); + KASSERT((incr & PAGE_MASK) == 0, ("%s: incr: %ju & PAGE_MASK", __func__, + (uintmax_t)incr)); #ifdef RACCT if (racct_enable) { PROC_LOCK(curproc); error = racct_add(curproc, RACCT_SWAP, incr); PROC_UNLOCK(curproc); if (error != 0) return (0); } #endif + pincr = atop(incr); res = 0; - mtx_lock(&sw_dev_mtx); - r = swap_reserved + incr; + prev = atomic_fetchadd_long(&swap_reserved, pincr); + r = prev + pincr; if (overcommit & SWAP_RESERVE_ALLOW_NONWIRED) { s = vm_cnt.v_page_count - vm_cnt.v_free_reserved - vm_wire_count(); - s *= PAGE_SIZE; } else s = 0; s += swap_total; if ((overcommit & SWAP_RESERVE_FORCE_ON) == 0 || r <= s || (error = priv_check(curthread, PRIV_VM_SWAP_NOQUOTA)) == 0) { res = 1; - swap_reserved = r; + } else { + prev = atomic_fetchadd_long(&swap_reserved, -pincr); + if (prev < pincr) + panic("swap_reserved < incr on overcommit fail"); } - mtx_unlock(&sw_dev_mtx); - if (res) { - UIDINFO_VMSIZE_LOCK(uip); + prev = atomic_fetchadd_long(&uip->ui_vmsize, pincr); if ((overcommit & SWAP_RESERVE_RLIMIT_ON) != 0 && - uip->ui_vmsize + incr > lim_cur(curthread, RLIMIT_SWAP) && - priv_check(curthread, PRIV_VM_SWAP_NORLIMIT)) + prev + pincr > lim_cur(curthread, RLIMIT_SWAP) && + priv_check(curthread, PRIV_VM_SWAP_NORLIMIT)) { res = 0; - else - uip->ui_vmsize += incr; - UIDINFO_VMSIZE_UNLOCK(uip); - if (!res) { - mtx_lock(&sw_dev_mtx); - swap_reserved -= incr; - mtx_unlock(&sw_dev_mtx); + prev = atomic_fetchadd_long(&uip->ui_vmsize, -pincr); + if (prev < pincr) + panic("uip->ui_vmsize < incr on overcommit fail"); } } if (!res && ppsratecheck(&lastfail, &curfail, 1)) { printf("uid %d, pid %d: swap reservation for %jd bytes failed\n", uip->ui_uid, curproc->p_pid, incr); } #ifdef RACCT - if (!res) { + if (racct_enable && !res) { PROC_LOCK(curproc); racct_sub(curproc, RACCT_SWAP, incr); PROC_UNLOCK(curproc); } #endif return (res); } void swap_reserve_force(vm_ooffset_t incr) { struct uidinfo *uip; + u_long pincr; - mtx_lock(&sw_dev_mtx); - swap_reserved += incr; - mtx_unlock(&sw_dev_mtx); + KASSERT((incr & PAGE_MASK) == 0, ("%s: incr: %ju & PAGE_MASK", __func__, + (uintmax_t)incr)); -#ifdef RACCT PROC_LOCK(curproc); - racct_add_force(curproc, RACCT_SWAP, incr); - PROC_UNLOCK(curproc); +#ifdef RACCT + if (racct_enable) + racct_add_force(curproc, RACCT_SWAP, incr); #endif - - uip = curthread->td_ucred->cr_ruidinfo; - PROC_LOCK(curproc); - UIDINFO_VMSIZE_LOCK(uip); - uip->ui_vmsize += incr; - UIDINFO_VMSIZE_UNLOCK(uip); + pincr = atop(incr); + atomic_add_long(&swap_reserved, pincr); + uip = curproc->p_ucred->cr_ruidinfo; + atomic_add_long(&uip->ui_vmsize, pincr); PROC_UNLOCK(curproc); } void swap_release(vm_ooffset_t decr) { struct ucred *cred; PROC_LOCK(curproc); - cred = curthread->td_ucred; + cred = curproc->p_ucred; swap_release_by_cred(decr, cred); PROC_UNLOCK(curproc); } void swap_release_by_cred(vm_ooffset_t decr, struct ucred *cred) { + u_long prev, pdecr; struct uidinfo *uip; uip = cred->cr_ruidinfo; - if (decr & PAGE_MASK) - panic("swap_release: & PAGE_MASK"); + KASSERT((decr & PAGE_MASK) == 0, ("%s: decr: %ju & PAGE_MASK", __func__, + (uintmax_t)decr)); - mtx_lock(&sw_dev_mtx); - if (swap_reserved < decr) + pdecr = atop(decr); + prev = atomic_fetchadd_long(&swap_reserved, -pdecr); + if (prev < pdecr) panic("swap_reserved < decr"); - swap_reserved -= decr; - mtx_unlock(&sw_dev_mtx); - UIDINFO_VMSIZE_LOCK(uip); - if (uip->ui_vmsize < decr) + prev = atomic_fetchadd_long(&uip->ui_vmsize, -pdecr); + if (prev < pdecr) printf("negative vmsize for uid = %d\n", uip->ui_uid); - uip->ui_vmsize -= decr; - UIDINFO_VMSIZE_UNLOCK(uip); - - racct_sub_cred(cred, RACCT_SWAP, decr); +#ifdef RACCT + if (racct_enable) + racct_sub_cred(cred, RACCT_SWAP, decr); +#endif } #define SWM_POP 0x01 /* pop out */ static int swap_pager_full = 2; /* swap space exhaustion (task killing) */ static int swap_pager_almost_full = 1; /* swap space exhaustion (w/hysteresis)*/ static int nsw_rcount; /* free read buffers */ static int nsw_wcount_sync; /* limit write buffers / synchronous */ static int nsw_wcount_async; /* limit write buffers / asynchronous */ static int nsw_wcount_async_max;/* assigned maximum */ static int nsw_cluster_max; /* maximum VOP I/O allowed */ static int sysctl_swap_async_max(SYSCTL_HANDLER_ARGS); SYSCTL_PROC(_vm, OID_AUTO, swap_async_max, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0, sysctl_swap_async_max, "I", "Maximum running async swap ops"); static int sysctl_swap_fragmentation(SYSCTL_HANDLER_ARGS); SYSCTL_PROC(_vm, OID_AUTO, swap_fragmentation, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_swap_fragmentation, "A", "Swap Fragmentation Info"); static struct sx sw_alloc_sx; /* * "named" and "unnamed" anon region objects. Try to reduce the overhead * of searching a named list by hashing it just a little. */ #define NOBJLISTS 8 #define NOBJLIST(handle) \ (&swap_pager_object_list[((int)(intptr_t)handle >> 4) & (NOBJLISTS-1)]) static struct pagerlst swap_pager_object_list[NOBJLISTS]; static uma_zone_t swblk_zone; static uma_zone_t swpctrie_zone; /* * pagerops for OBJT_SWAP - "swap pager". Some ops are also global procedure * calls hooked from other parts of the VM system and do not appear here. * (see vm/swap_pager.h). */ static vm_object_t swap_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t offset, struct ucred *); static void swap_pager_dealloc(vm_object_t object); static int swap_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); static int swap_pager_getpages_async(vm_object_t, vm_page_t *, int, int *, int *, pgo_getpages_iodone_t, void *); static void swap_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *); static boolean_t swap_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, int *after); static void swap_pager_init(void); static void swap_pager_unswapped(vm_page_t); static void swap_pager_swapoff(struct swdevt *sp); struct pagerops swappagerops = { .pgo_init = swap_pager_init, /* early system initialization of pager */ .pgo_alloc = swap_pager_alloc, /* allocate an OBJT_SWAP object */ .pgo_dealloc = swap_pager_dealloc, /* deallocate an OBJT_SWAP object */ .pgo_getpages = swap_pager_getpages, /* pagein */ .pgo_getpages_async = swap_pager_getpages_async, /* pagein (async) */ .pgo_putpages = swap_pager_putpages, /* pageout */ .pgo_haspage = swap_pager_haspage, /* get backing store status for page */ .pgo_pageunswapped = swap_pager_unswapped, /* remove swap related to page */ }; /* * swap_*() routines are externally accessible. swp_*() routines are * internal. */ static int nswap_lowat = 128; /* in pages, swap_pager_almost_full warn */ static int nswap_hiwat = 512; /* in pages, swap_pager_almost_full warn */ SYSCTL_INT(_vm, OID_AUTO, dmmax, CTLFLAG_RD, &nsw_cluster_max, 0, "Maximum size of a swap block in pages"); static void swp_sizecheck(void); static void swp_pager_async_iodone(struct buf *bp); static bool swp_pager_swblk_empty(struct swblk *sb, int start, int limit); static int swapongeom(struct vnode *); static int swaponvp(struct thread *, struct vnode *, u_long); static int swapoff_one(struct swdevt *sp, struct ucred *cred); /* * Swap bitmap functions */ static void swp_pager_freeswapspace(daddr_t blk, daddr_t npages); static daddr_t swp_pager_getswapspace(int npages); /* * Metadata functions */ static daddr_t swp_pager_meta_build(vm_object_t, vm_pindex_t, daddr_t); static void swp_pager_meta_free(vm_object_t, vm_pindex_t, vm_pindex_t); static void swp_pager_meta_free_all(vm_object_t); static daddr_t swp_pager_meta_ctl(vm_object_t, vm_pindex_t, int); static void swp_pager_init_freerange(daddr_t *start, daddr_t *num) { *start = SWAPBLK_NONE; *num = 0; } static void swp_pager_update_freerange(daddr_t *start, daddr_t *num, daddr_t addr) { if (*start + *num == addr) { (*num)++; } else { swp_pager_freeswapspace(*start, *num); *start = addr; *num = 1; } } static void * swblk_trie_alloc(struct pctrie *ptree) { return (uma_zalloc(swpctrie_zone, M_NOWAIT | (curproc == pageproc ? M_USE_RESERVE : 0))); } static void swblk_trie_free(struct pctrie *ptree, void *node) { uma_zfree(swpctrie_zone, node); } PCTRIE_DEFINE(SWAP, swblk, p, swblk_trie_alloc, swblk_trie_free); /* * SWP_SIZECHECK() - update swap_pager_full indication * * update the swap_pager_almost_full indication and warn when we are * about to run out of swap space, using lowat/hiwat hysteresis. * * Clear swap_pager_full ( task killing ) indication when lowat is met. * * No restrictions on call * This routine may not block. */ static void swp_sizecheck(void) { if (swap_pager_avail < nswap_lowat) { if (swap_pager_almost_full == 0) { printf("swap_pager: out of swap space\n"); swap_pager_almost_full = 1; } } else { swap_pager_full = 0; if (swap_pager_avail > nswap_hiwat) swap_pager_almost_full = 0; } } /* * SWAP_PAGER_INIT() - initialize the swap pager! * * Expected to be started from system init. NOTE: This code is run * before much else so be careful what you depend on. Most of the VM * system has yet to be initialized at this point. */ static void swap_pager_init(void) { /* * Initialize object lists */ int i; for (i = 0; i < NOBJLISTS; ++i) TAILQ_INIT(&swap_pager_object_list[i]); mtx_init(&sw_dev_mtx, "swapdev", NULL, MTX_DEF); sx_init(&sw_alloc_sx, "swspsx"); sx_init(&swdev_syscall_lock, "swsysc"); } /* * SWAP_PAGER_SWAP_INIT() - swap pager initialization from pageout process * * Expected to be started from pageout process once, prior to entering * its main loop. */ void swap_pager_swap_init(void) { unsigned long n, n2; /* * Number of in-transit swap bp operations. Don't * exhaust the pbufs completely. Make sure we * initialize workable values (0 will work for hysteresis * but it isn't very efficient). * * The nsw_cluster_max is constrained by the bp->b_pages[] * array (MAXPHYS/PAGE_SIZE) and our locally defined * MAX_PAGEOUT_CLUSTER. Also be aware that swap ops are * constrained by the swap device interleave stripe size. * * Currently we hardwire nsw_wcount_async to 4. This limit is * designed to prevent other I/O from having high latencies due to * our pageout I/O. The value 4 works well for one or two active swap * devices but is probably a little low if you have more. Even so, * a higher value would probably generate only a limited improvement * with three or four active swap devices since the system does not * typically have to pageout at extreme bandwidths. We will want * at least 2 per swap devices, and 4 is a pretty good value if you * have one NFS swap device due to the command/ack latency over NFS. * So it all works out pretty well. */ nsw_cluster_max = min((MAXPHYS/PAGE_SIZE), MAX_PAGEOUT_CLUSTER); mtx_lock(&pbuf_mtx); nsw_rcount = (nswbuf + 1) / 2; nsw_wcount_sync = (nswbuf + 3) / 4; nsw_wcount_async = 4; nsw_wcount_async_max = nsw_wcount_async; mtx_unlock(&pbuf_mtx); /* * Initialize our zone, guessing on the number we need based * on the number of pages in the system. */ n = vm_cnt.v_page_count / 2; if (maxswzone && n > maxswzone / sizeof(struct swblk)) n = maxswzone / sizeof(struct swblk); swpctrie_zone = uma_zcreate("swpctrie", pctrie_node_size(), NULL, NULL, pctrie_zone_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM); if (swpctrie_zone == NULL) panic("failed to create swap pctrie zone."); swblk_zone = uma_zcreate("swblk", sizeof(struct swblk), NULL, NULL, NULL, NULL, _Alignof(struct swblk) - 1, UMA_ZONE_VM); if (swblk_zone == NULL) panic("failed to create swap blk zone."); n2 = n; do { if (uma_zone_reserve_kva(swblk_zone, n)) break; /* * if the allocation failed, try a zone two thirds the * size of the previous attempt. */ n -= ((n + 2) / 3); } while (n > 0); /* * Often uma_zone_reserve_kva() cannot reserve exactly the * requested size. Account for the difference when * calculating swap_maxpages. */ n = uma_zone_get_max(swblk_zone); if (n < n2) printf("Swap blk zone entries reduced from %lu to %lu.\n", n2, n); swap_maxpages = n * SWAP_META_PAGES; swzone = n * sizeof(struct swblk); if (!uma_zone_reserve_kva(swpctrie_zone, n)) printf("Cannot reserve swap pctrie zone, " "reduce kern.maxswzone.\n"); } static vm_object_t swap_pager_alloc_init(void *handle, struct ucred *cred, vm_ooffset_t size, vm_ooffset_t offset) { vm_object_t object; if (cred != NULL) { if (!swap_reserve_by_cred(size, cred)) return (NULL); crhold(cred); } /* * The un_pager.swp.swp_blks trie is initialized by * vm_object_allocate() to ensure the correct order of * visibility to other threads. */ object = vm_object_allocate(OBJT_SWAP, OFF_TO_IDX(offset + PAGE_MASK + size)); object->handle = handle; if (cred != NULL) { object->cred = cred; object->charge = size; } return (object); } /* * SWAP_PAGER_ALLOC() - allocate a new OBJT_SWAP VM object and instantiate * its metadata structures. * * This routine is called from the mmap and fork code to create a new * OBJT_SWAP object. * * This routine must ensure that no live duplicate is created for * the named object request, which is protected against by * holding the sw_alloc_sx lock in case handle != NULL. */ static vm_object_t swap_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t offset, struct ucred *cred) { vm_object_t object; if (handle != NULL) { /* * Reference existing named region or allocate new one. There * should not be a race here against swp_pager_meta_build() * as called from vm_page_remove() in regards to the lookup * of the handle. */ sx_xlock(&sw_alloc_sx); object = vm_pager_object_lookup(NOBJLIST(handle), handle); if (object == NULL) { object = swap_pager_alloc_init(handle, cred, size, offset); if (object != NULL) { TAILQ_INSERT_TAIL(NOBJLIST(object->handle), object, pager_object_list); } } sx_xunlock(&sw_alloc_sx); } else { object = swap_pager_alloc_init(handle, cred, size, offset); } return (object); } /* * SWAP_PAGER_DEALLOC() - remove swap metadata from object * * The swap backing for the object is destroyed. The code is * designed such that we can reinstantiate it later, but this * routine is typically called only when the entire object is * about to be destroyed. * * The object must be locked. */ static void swap_pager_dealloc(vm_object_t object) { VM_OBJECT_ASSERT_WLOCKED(object); KASSERT((object->flags & OBJ_DEAD) != 0, ("dealloc of reachable obj")); /* * Remove from list right away so lookups will fail if we block for * pageout completion. */ if (object->handle != NULL) { VM_OBJECT_WUNLOCK(object); sx_xlock(&sw_alloc_sx); TAILQ_REMOVE(NOBJLIST(object->handle), object, pager_object_list); sx_xunlock(&sw_alloc_sx); VM_OBJECT_WLOCK(object); } vm_object_pip_wait(object, "swpdea"); /* * Free all remaining metadata. We only bother to free it from * the swap meta data. We do not attempt to free swapblk's still * associated with vm_page_t's for this object. We do not care * if paging is still in progress on some objects. */ swp_pager_meta_free_all(object); object->handle = NULL; object->type = OBJT_DEAD; } /************************************************************************ * SWAP PAGER BITMAP ROUTINES * ************************************************************************/ /* * SWP_PAGER_GETSWAPSPACE() - allocate raw swap space * * Allocate swap for the requested number of pages. The starting * swap block number (a page index) is returned or SWAPBLK_NONE * if the allocation failed. * * Also has the side effect of advising that somebody made a mistake * when they configured swap and didn't configure enough. * * This routine may not sleep. * * We allocate in round-robin fashion from the configured devices. */ static daddr_t swp_pager_getswapspace(int npages) { daddr_t blk; struct swdevt *sp; int i; blk = SWAPBLK_NONE; mtx_lock(&sw_dev_mtx); sp = swdevhd; for (i = 0; i < nswapdev; i++) { if (sp == NULL) sp = TAILQ_FIRST(&swtailq); if (!(sp->sw_flags & SW_CLOSING)) { blk = blist_alloc(sp->sw_blist, npages); if (blk != SWAPBLK_NONE) { blk += sp->sw_first; sp->sw_used += npages; swap_pager_avail -= npages; swp_sizecheck(); swdevhd = TAILQ_NEXT(sp, sw_list); goto done; } } sp = TAILQ_NEXT(sp, sw_list); } if (swap_pager_full != 2) { printf("swap_pager_getswapspace(%d): failed\n", npages); swap_pager_full = 2; swap_pager_almost_full = 1; } swdevhd = NULL; done: mtx_unlock(&sw_dev_mtx); return (blk); } static int swp_pager_isondev(daddr_t blk, struct swdevt *sp) { return (blk >= sp->sw_first && blk < sp->sw_end); } static void swp_pager_strategy(struct buf *bp) { struct swdevt *sp; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (bp->b_blkno >= sp->sw_first && bp->b_blkno < sp->sw_end) { mtx_unlock(&sw_dev_mtx); if ((sp->sw_flags & SW_UNMAPPED) != 0 && unmapped_buf_allowed) { bp->b_data = unmapped_buf; bp->b_offset = 0; } else { pmap_qenter((vm_offset_t)bp->b_data, &bp->b_pages[0], bp->b_bcount / PAGE_SIZE); } sp->sw_strategy(bp, sp); return; } } panic("Swapdev not found"); } /* * SWP_PAGER_FREESWAPSPACE() - free raw swap space * * This routine returns the specified swap blocks back to the bitmap. * * This routine may not sleep. */ static void swp_pager_freeswapspace(daddr_t blk, daddr_t npages) { struct swdevt *sp; if (npages == 0) return; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (blk >= sp->sw_first && blk < sp->sw_end) { sp->sw_used -= npages; /* * If we are attempting to stop swapping on * this device, we don't want to mark any * blocks free lest they be reused. */ if ((sp->sw_flags & SW_CLOSING) == 0) { blist_free(sp->sw_blist, blk - sp->sw_first, npages); swap_pager_avail += npages; swp_sizecheck(); } mtx_unlock(&sw_dev_mtx); return; } } panic("Swapdev not found"); } /* * SYSCTL_SWAP_FRAGMENTATION() - produce raw swap space stats */ static int sysctl_swap_fragmentation(SYSCTL_HANDLER_ARGS) { struct sbuf sbuf; struct swdevt *sp; const char *devname; int error; error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); sbuf_new_for_sysctl(&sbuf, NULL, 128, req); mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (vn_isdisk(sp->sw_vp, NULL)) devname = devtoname(sp->sw_vp->v_rdev); else devname = "[file]"; sbuf_printf(&sbuf, "\nFree space on device %s:\n", devname); blist_stats(sp->sw_blist, &sbuf); } mtx_unlock(&sw_dev_mtx); error = sbuf_finish(&sbuf); sbuf_delete(&sbuf); return (error); } /* * SWAP_PAGER_FREESPACE() - frees swap blocks associated with a page * range within an object. * * This is a globally accessible routine. * * This routine removes swapblk assignments from swap metadata. * * The external callers of this routine typically have already destroyed * or renamed vm_page_t's associated with this range in the object so * we should be ok. * * The object must be locked. */ void swap_pager_freespace(vm_object_t object, vm_pindex_t start, vm_size_t size) { swp_pager_meta_free(object, start, size); } /* * SWAP_PAGER_RESERVE() - reserve swap blocks in object * * Assigns swap blocks to the specified range within the object. The * swap blocks are not zeroed. Any previous swap assignment is destroyed. * * Returns 0 on success, -1 on failure. */ int swap_pager_reserve(vm_object_t object, vm_pindex_t start, vm_size_t size) { int n = 0; daddr_t blk = SWAPBLK_NONE; vm_pindex_t beg = start; /* save start index */ daddr_t addr, n_free, s_free; swp_pager_init_freerange(&s_free, &n_free); VM_OBJECT_WLOCK(object); while (size) { if (n == 0) { n = BLIST_MAX_ALLOC; while ((blk = swp_pager_getswapspace(n)) == SWAPBLK_NONE) { n >>= 1; if (n == 0) { swp_pager_meta_free(object, beg, start - beg); VM_OBJECT_WUNLOCK(object); return (-1); } } } addr = swp_pager_meta_build(object, start, blk); if (addr != SWAPBLK_NONE) swp_pager_update_freerange(&s_free, &n_free, addr); --size; ++start; ++blk; --n; } swp_pager_freeswapspace(s_free, n_free); swp_pager_meta_free(object, start, n); VM_OBJECT_WUNLOCK(object); return (0); } /* * SWAP_PAGER_COPY() - copy blocks from source pager to destination pager * and destroy the source. * * Copy any valid swapblks from the source to the destination. In * cases where both the source and destination have a valid swapblk, * we keep the destination's. * * This routine is allowed to sleep. It may sleep allocating metadata * indirectly through swp_pager_meta_build() or if paging is still in * progress on the source. * * The source object contains no vm_page_t's (which is just as well) * * The source object is of type OBJT_SWAP. * * The source and destination objects must be locked. * Both object locks may temporarily be released. */ void swap_pager_copy(vm_object_t srcobject, vm_object_t dstobject, vm_pindex_t offset, int destroysource) { vm_pindex_t i; daddr_t dstaddr, n_free, s_free, srcaddr; VM_OBJECT_ASSERT_WLOCKED(srcobject); VM_OBJECT_ASSERT_WLOCKED(dstobject); /* * If destroysource is set, we remove the source object from the * swap_pager internal queue now. */ if (destroysource && srcobject->handle != NULL) { vm_object_pip_add(srcobject, 1); VM_OBJECT_WUNLOCK(srcobject); vm_object_pip_add(dstobject, 1); VM_OBJECT_WUNLOCK(dstobject); sx_xlock(&sw_alloc_sx); TAILQ_REMOVE(NOBJLIST(srcobject->handle), srcobject, pager_object_list); sx_xunlock(&sw_alloc_sx); VM_OBJECT_WLOCK(dstobject); vm_object_pip_wakeup(dstobject); VM_OBJECT_WLOCK(srcobject); vm_object_pip_wakeup(srcobject); } /* * Transfer source to destination. */ swp_pager_init_freerange(&s_free, &n_free); for (i = 0; i < dstobject->size; ++i) { srcaddr = swp_pager_meta_ctl(srcobject, i + offset, SWM_POP); if (srcaddr == SWAPBLK_NONE) continue; dstaddr = swp_pager_meta_ctl(dstobject, i, 0); if (dstaddr != SWAPBLK_NONE) { /* * Destination has valid swapblk or it is represented * by a resident page. We destroy the source block. */ swp_pager_update_freerange(&s_free, &n_free, srcaddr); continue; } /* * Destination has no swapblk and is not resident, * copy source. * * swp_pager_meta_build() can sleep. */ vm_object_pip_add(srcobject, 1); VM_OBJECT_WUNLOCK(srcobject); vm_object_pip_add(dstobject, 1); dstaddr = swp_pager_meta_build(dstobject, i, srcaddr); KASSERT(dstaddr == SWAPBLK_NONE, ("Unexpected destination swapblk")); vm_object_pip_wakeup(dstobject); VM_OBJECT_WLOCK(srcobject); vm_object_pip_wakeup(srcobject); } swp_pager_freeswapspace(s_free, n_free); /* * Free left over swap blocks in source. * * We have to revert the type to OBJT_DEFAULT so we do not accidentally * double-remove the object from the swap queues. */ if (destroysource) { swp_pager_meta_free_all(srcobject); /* * Reverting the type is not necessary, the caller is going * to destroy srcobject directly, but I'm doing it here * for consistency since we've removed the object from its * queues. */ srcobject->type = OBJT_DEFAULT; } } /* * SWAP_PAGER_HASPAGE() - determine if we have good backing store for * the requested page. * * We determine whether good backing store exists for the requested * page and return TRUE if it does, FALSE if it doesn't. * * If TRUE, we also try to determine how much valid, contiguous backing * store exists before and after the requested page. */ static boolean_t swap_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, int *after) { daddr_t blk, blk0; int i; VM_OBJECT_ASSERT_LOCKED(object); /* * do we have good backing store at the requested index ? */ blk0 = swp_pager_meta_ctl(object, pindex, 0); if (blk0 == SWAPBLK_NONE) { if (before) *before = 0; if (after) *after = 0; return (FALSE); } /* * find backwards-looking contiguous good backing store */ if (before != NULL) { for (i = 1; i < SWB_NPAGES; i++) { if (i > pindex) break; blk = swp_pager_meta_ctl(object, pindex - i, 0); if (blk != blk0 - i) break; } *before = i - 1; } /* * find forward-looking contiguous good backing store */ if (after != NULL) { for (i = 1; i < SWB_NPAGES; i++) { blk = swp_pager_meta_ctl(object, pindex + i, 0); if (blk != blk0 + i) break; } *after = i - 1; } return (TRUE); } /* * SWAP_PAGER_PAGE_UNSWAPPED() - remove swap backing store related to page * * This removes any associated swap backing store, whether valid or * not, from the page. * * This routine is typically called when a page is made dirty, at * which point any associated swap can be freed. MADV_FREE also * calls us in a special-case situation * * NOTE!!! If the page is clean and the swap was valid, the caller * should make the page dirty before calling this routine. This routine * does NOT change the m->dirty status of the page. Also: MADV_FREE * depends on it. * * This routine may not sleep. * * The object containing the page must be locked. */ static void swap_pager_unswapped(vm_page_t m) { daddr_t srcaddr; srcaddr = swp_pager_meta_ctl(m->object, m->pindex, SWM_POP); if (srcaddr != SWAPBLK_NONE) swp_pager_freeswapspace(srcaddr, 1); } /* * swap_pager_getpages() - bring pages in from swap * * Attempt to page in the pages in array "ma" of length "count". The * caller may optionally specify that additional pages preceding and * succeeding the specified range be paged in. The number of such pages * is returned in the "rbehind" and "rahead" parameters, and they will * be in the inactive queue upon return. * * The pages in "ma" must be busied and will remain busied upon return. */ static int swap_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, int *rahead) { struct buf *bp; vm_page_t bm, mpred, msucc, p; vm_pindex_t pindex; daddr_t blk; int i, maxahead, maxbehind, reqcount; reqcount = count; /* * Determine the final number of read-behind pages and * allocate them BEFORE releasing the object lock. Otherwise, * there can be a problematic race with vm_object_split(). * Specifically, vm_object_split() might first transfer pages * that precede ma[0] in the current object to a new object, * and then this function incorrectly recreates those pages as * read-behind pages in the current object. */ if (!swap_pager_haspage(object, ma[0]->pindex, &maxbehind, &maxahead)) return (VM_PAGER_FAIL); /* * Clip the readahead and readbehind ranges to exclude resident pages. */ if (rahead != NULL) { KASSERT(reqcount - 1 <= maxahead, ("page count %d extends beyond swap block", reqcount)); *rahead = imin(*rahead, maxahead - (reqcount - 1)); pindex = ma[reqcount - 1]->pindex; msucc = TAILQ_NEXT(ma[reqcount - 1], listq); if (msucc != NULL && msucc->pindex - pindex - 1 < *rahead) *rahead = msucc->pindex - pindex - 1; } if (rbehind != NULL) { *rbehind = imin(*rbehind, maxbehind); pindex = ma[0]->pindex; mpred = TAILQ_PREV(ma[0], pglist, listq); if (mpred != NULL && pindex - mpred->pindex - 1 < *rbehind) *rbehind = pindex - mpred->pindex - 1; } bm = ma[0]; for (i = 0; i < count; i++) ma[i]->oflags |= VPO_SWAPINPROG; /* * Allocate readahead and readbehind pages. */ if (rbehind != NULL) { for (i = 1; i <= *rbehind; i++) { p = vm_page_alloc(object, ma[0]->pindex - i, VM_ALLOC_NORMAL); if (p == NULL) break; p->oflags |= VPO_SWAPINPROG; bm = p; } *rbehind = i - 1; } if (rahead != NULL) { for (i = 0; i < *rahead; i++) { p = vm_page_alloc(object, ma[reqcount - 1]->pindex + i + 1, VM_ALLOC_NORMAL); if (p == NULL) break; p->oflags |= VPO_SWAPINPROG; } *rahead = i; } if (rbehind != NULL) count += *rbehind; if (rahead != NULL) count += *rahead; vm_object_pip_add(object, count); pindex = bm->pindex; blk = swp_pager_meta_ctl(object, pindex, 0); KASSERT(blk != SWAPBLK_NONE, ("no swap blocking containing %p(%jx)", object, (uintmax_t)pindex)); VM_OBJECT_WUNLOCK(object); bp = getpbuf(&nsw_rcount); /* Pages cannot leave the object while busy. */ for (i = 0, p = bm; i < count; i++, p = TAILQ_NEXT(p, listq)) { MPASS(p->pindex == bm->pindex + i); bp->b_pages[i] = p; } bp->b_flags |= B_PAGING; bp->b_iocmd = BIO_READ; bp->b_iodone = swp_pager_async_iodone; bp->b_rcred = crhold(thread0.td_ucred); bp->b_wcred = crhold(thread0.td_ucred); bp->b_blkno = blk; bp->b_bcount = PAGE_SIZE * count; bp->b_bufsize = PAGE_SIZE * count; bp->b_npages = count; bp->b_pgbefore = rbehind != NULL ? *rbehind : 0; bp->b_pgafter = rahead != NULL ? *rahead : 0; VM_CNT_INC(v_swapin); VM_CNT_ADD(v_swappgsin, count); /* * perform the I/O. NOTE!!! bp cannot be considered valid after * this point because we automatically release it on completion. * Instead, we look at the one page we are interested in which we * still hold a lock on even through the I/O completion. * * The other pages in our ma[] array are also released on completion, * so we cannot assume they are valid anymore either. * * NOTE: b_blkno is destroyed by the call to swapdev_strategy */ BUF_KERNPROC(bp); swp_pager_strategy(bp); /* * Wait for the pages we want to complete. VPO_SWAPINPROG is always * cleared on completion. If an I/O error occurs, SWAPBLK_NONE * is set in the metadata for each page in the request. */ VM_OBJECT_WLOCK(object); while ((ma[0]->oflags & VPO_SWAPINPROG) != 0) { ma[0]->oflags |= VPO_SWAPSLEEP; VM_CNT_INC(v_intrans); if (VM_OBJECT_SLEEP(object, &object->paging_in_progress, PSWP, "swread", hz * 20)) { printf( "swap_pager: indefinite wait buffer: bufobj: %p, blkno: %jd, size: %ld\n", bp->b_bufobj, (intmax_t)bp->b_blkno, bp->b_bcount); } } /* * If we had an unrecoverable read error pages will not be valid. */ for (i = 0; i < reqcount; i++) if (ma[i]->valid != VM_PAGE_BITS_ALL) return (VM_PAGER_ERROR); return (VM_PAGER_OK); /* * A final note: in a low swap situation, we cannot deallocate swap * and mark a page dirty here because the caller is likely to mark * the page clean when we return, causing the page to possibly revert * to all-zero's later. */ } /* * swap_pager_getpages_async(): * * Right now this is emulation of asynchronous operation on top of * swap_pager_getpages(). */ static int swap_pager_getpages_async(vm_object_t object, vm_page_t *ma, int count, int *rbehind, int *rahead, pgo_getpages_iodone_t iodone, void *arg) { int r, error; r = swap_pager_getpages(object, ma, count, rbehind, rahead); VM_OBJECT_WUNLOCK(object); switch (r) { case VM_PAGER_OK: error = 0; break; case VM_PAGER_ERROR: error = EIO; break; case VM_PAGER_FAIL: error = EINVAL; break; default: panic("unhandled swap_pager_getpages() error %d", r); } (iodone)(arg, ma, count, error); VM_OBJECT_WLOCK(object); return (r); } /* * swap_pager_putpages: * * Assign swap (if necessary) and initiate I/O on the specified pages. * * We support both OBJT_DEFAULT and OBJT_SWAP objects. DEFAULT objects * are automatically converted to SWAP objects. * * In a low memory situation we may block in VOP_STRATEGY(), but the new * vm_page reservation system coupled with properly written VFS devices * should ensure that no low-memory deadlock occurs. This is an area * which needs work. * * The parent has N vm_object_pip_add() references prior to * calling us and will remove references for rtvals[] that are * not set to VM_PAGER_PEND. We need to remove the rest on I/O * completion. * * The parent has soft-busy'd the pages it passes us and will unbusy * those whos rtvals[] entry is not set to VM_PAGER_PEND on return. * We need to unbusy the rest on I/O completion. */ static void swap_pager_putpages(vm_object_t object, vm_page_t *ma, int count, int flags, int *rtvals) { int i, n; boolean_t sync; daddr_t addr, n_free, s_free; swp_pager_init_freerange(&s_free, &n_free); if (count && ma[0]->object != object) { panic("swap_pager_putpages: object mismatch %p/%p", object, ma[0]->object ); } /* * Step 1 * * Turn object into OBJT_SWAP * check for bogus sysops * force sync if not pageout process */ if (object->type != OBJT_SWAP) { addr = swp_pager_meta_build(object, 0, SWAPBLK_NONE); KASSERT(addr == SWAPBLK_NONE, ("unexpected object swap block")); } VM_OBJECT_WUNLOCK(object); n = 0; if (curproc != pageproc) sync = TRUE; else sync = (flags & VM_PAGER_PUT_SYNC) != 0; /* * Step 2 * * Assign swap blocks and issue I/O. We reallocate swap on the fly. * The page is left dirty until the pageout operation completes * successfully. */ for (i = 0; i < count; i += n) { int j; struct buf *bp; daddr_t blk; /* * Maximum I/O size is limited by a number of factors. */ n = min(BLIST_MAX_ALLOC, count - i); n = min(n, nsw_cluster_max); /* * Get biggest block of swap we can. If we fail, fall * back and try to allocate a smaller block. Don't go * overboard trying to allocate space if it would overly * fragment swap. */ while ( (blk = swp_pager_getswapspace(n)) == SWAPBLK_NONE && n > 4 ) { n >>= 1; } if (blk == SWAPBLK_NONE) { for (j = 0; j < n; ++j) rtvals[i+j] = VM_PAGER_FAIL; continue; } /* * All I/O parameters have been satisfied, build the I/O * request and assign the swap space. */ if (sync == TRUE) { bp = getpbuf(&nsw_wcount_sync); } else { bp = getpbuf(&nsw_wcount_async); bp->b_flags = B_ASYNC; } bp->b_flags |= B_PAGING; bp->b_iocmd = BIO_WRITE; bp->b_rcred = crhold(thread0.td_ucred); bp->b_wcred = crhold(thread0.td_ucred); bp->b_bcount = PAGE_SIZE * n; bp->b_bufsize = PAGE_SIZE * n; bp->b_blkno = blk; VM_OBJECT_WLOCK(object); for (j = 0; j < n; ++j) { vm_page_t mreq = ma[i+j]; addr = swp_pager_meta_build(mreq->object, mreq->pindex, blk + j); if (addr != SWAPBLK_NONE) swp_pager_update_freerange(&s_free, &n_free, addr); MPASS(mreq->dirty == VM_PAGE_BITS_ALL); mreq->oflags |= VPO_SWAPINPROG; bp->b_pages[j] = mreq; } VM_OBJECT_WUNLOCK(object); bp->b_npages = n; /* * Must set dirty range for NFS to work. */ bp->b_dirtyoff = 0; bp->b_dirtyend = bp->b_bcount; VM_CNT_INC(v_swapout); VM_CNT_ADD(v_swappgsout, bp->b_npages); /* * We unconditionally set rtvals[] to VM_PAGER_PEND so that we * can call the async completion routine at the end of a * synchronous I/O operation. Otherwise, our caller would * perform duplicate unbusy and wakeup operations on the page * and object, respectively. */ for (j = 0; j < n; j++) rtvals[i + j] = VM_PAGER_PEND; /* * asynchronous * * NOTE: b_blkno is destroyed by the call to swapdev_strategy */ if (sync == FALSE) { bp->b_iodone = swp_pager_async_iodone; BUF_KERNPROC(bp); swp_pager_strategy(bp); continue; } /* * synchronous * * NOTE: b_blkno is destroyed by the call to swapdev_strategy */ bp->b_iodone = bdone; swp_pager_strategy(bp); /* * Wait for the sync I/O to complete. */ bwait(bp, PVM, "swwrt"); /* * Now that we are through with the bp, we can call the * normal async completion, which frees everything up. */ swp_pager_async_iodone(bp); } VM_OBJECT_WLOCK(object); swp_pager_freeswapspace(s_free, n_free); } /* * swp_pager_async_iodone: * * Completion routine for asynchronous reads and writes from/to swap. * Also called manually by synchronous code to finish up a bp. * * This routine may not sleep. */ static void swp_pager_async_iodone(struct buf *bp) { int i; vm_object_t object = NULL; /* * report error */ if (bp->b_ioflags & BIO_ERROR) { printf( "swap_pager: I/O error - %s failed; blkno %ld," "size %ld, error %d\n", ((bp->b_iocmd == BIO_READ) ? "pagein" : "pageout"), (long)bp->b_blkno, (long)bp->b_bcount, bp->b_error ); } /* * remove the mapping for kernel virtual */ if (buf_mapped(bp)) pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages); else bp->b_data = bp->b_kvabase; if (bp->b_npages) { object = bp->b_pages[0]->object; VM_OBJECT_WLOCK(object); } /* * cleanup pages. If an error occurs writing to swap, we are in * very serious trouble. If it happens to be a disk error, though, * we may be able to recover by reassigning the swap later on. So * in this case we remove the m->swapblk assignment for the page * but do not free it in the rlist. The errornous block(s) are thus * never reallocated as swap. Redirty the page and continue. */ for (i = 0; i < bp->b_npages; ++i) { vm_page_t m = bp->b_pages[i]; m->oflags &= ~VPO_SWAPINPROG; if (m->oflags & VPO_SWAPSLEEP) { m->oflags &= ~VPO_SWAPSLEEP; wakeup(&object->paging_in_progress); } if (bp->b_ioflags & BIO_ERROR) { /* * If an error occurs I'd love to throw the swapblk * away without freeing it back to swapspace, so it * can never be used again. But I can't from an * interrupt. */ if (bp->b_iocmd == BIO_READ) { /* * NOTE: for reads, m->dirty will probably * be overridden by the original caller of * getpages so don't play cute tricks here. */ m->valid = 0; } else { /* * If a write error occurs, reactivate page * so it doesn't clog the inactive list, * then finish the I/O. */ MPASS(m->dirty == VM_PAGE_BITS_ALL); vm_page_lock(m); vm_page_activate(m); vm_page_unlock(m); vm_page_sunbusy(m); } } else if (bp->b_iocmd == BIO_READ) { /* * NOTE: for reads, m->dirty will probably be * overridden by the original caller of getpages so * we cannot set them in order to free the underlying * swap in a low-swap situation. I don't think we'd * want to do that anyway, but it was an optimization * that existed in the old swapper for a time before * it got ripped out due to precisely this problem. */ KASSERT(!pmap_page_is_mapped(m), ("swp_pager_async_iodone: page %p is mapped", m)); KASSERT(m->dirty == 0, ("swp_pager_async_iodone: page %p is dirty", m)); m->valid = VM_PAGE_BITS_ALL; if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter) vm_page_readahead_finish(m); } else { /* * For write success, clear the dirty * status, then finish the I/O ( which decrements the * busy count and possibly wakes waiter's up ). * A page is only written to swap after a period of * inactivity. Therefore, we do not expect it to be * reused. */ KASSERT(!pmap_page_is_write_mapped(m), ("swp_pager_async_iodone: page %p is not write" " protected", m)); vm_page_undirty(m); vm_page_lock(m); vm_page_deactivate_noreuse(m); vm_page_unlock(m); vm_page_sunbusy(m); } } /* * adjust pip. NOTE: the original parent may still have its own * pip refs on the object. */ if (object != NULL) { vm_object_pip_wakeupn(object, bp->b_npages); VM_OBJECT_WUNLOCK(object); } /* * swapdev_strategy() manually sets b_vp and b_bufobj before calling * bstrategy(). Set them back to NULL now we're done with it, or we'll * trigger a KASSERT in relpbuf(). */ if (bp->b_vp) { bp->b_vp = NULL; bp->b_bufobj = NULL; } /* * release the physical I/O buffer */ relpbuf( bp, ((bp->b_iocmd == BIO_READ) ? &nsw_rcount : ((bp->b_flags & B_ASYNC) ? &nsw_wcount_async : &nsw_wcount_sync ) ) ); } int swap_pager_nswapdev(void) { return (nswapdev); } /* * SWP_PAGER_FORCE_PAGEIN() - force a swap block to be paged in * * This routine dissociates the page at the given index within an object * from its backing store, paging it in if it does not reside in memory. * If the page is paged in, it is marked dirty and placed in the laundry * queue. The page is marked dirty because it no longer has backing * store. It is placed in the laundry queue because it has not been * accessed recently. Otherwise, it would already reside in memory. * * We also attempt to swap in all other pages in the swap block. * However, we only guarantee that the one at the specified index is * paged in. * * XXX - The code to page the whole block in doesn't work, so we * revert to the one-by-one behavior for now. Sigh. */ static inline void swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex) { vm_page_t m; vm_object_pip_add(object, 1); m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL); if (m->valid == VM_PAGE_BITS_ALL) { vm_object_pip_wakeup(object); vm_page_dirty(m); #ifdef INVARIANTS vm_page_lock(m); if (m->wire_count == 0 && m->queue == PQ_NONE) panic("page %p is neither wired nor queued", m); vm_page_unlock(m); #endif vm_page_xunbusy(m); vm_pager_page_unswapped(m); return; } if (swap_pager_getpages(object, &m, 1, NULL, NULL) != VM_PAGER_OK) panic("swap_pager_force_pagein: read from swap failed");/*XXX*/ vm_object_pip_wakeup(object); vm_page_dirty(m); vm_page_lock(m); vm_page_launder(m); vm_page_unlock(m); vm_page_xunbusy(m); vm_pager_page_unswapped(m); } /* * swap_pager_swapoff: * * Page in all of the pages that have been paged out to the * given device. The corresponding blocks in the bitmap must be * marked as allocated and the device must be flagged SW_CLOSING. * There may be no processes swapped out to the device. * * This routine may block. */ static void swap_pager_swapoff(struct swdevt *sp) { struct swblk *sb; vm_object_t object; vm_pindex_t pi; int i, retries; sx_assert(&swdev_syscall_lock, SA_XLOCKED); retries = 0; full_rescan: mtx_lock(&vm_object_list_mtx); TAILQ_FOREACH(object, &vm_object_list, object_list) { if (object->type != OBJT_SWAP) continue; mtx_unlock(&vm_object_list_mtx); /* Depends on type-stability. */ VM_OBJECT_WLOCK(object); /* * Dead objects are eventually terminated on their own. */ if ((object->flags & OBJ_DEAD) != 0) goto next_obj; /* * Sync with fences placed after pctrie * initialization. We must not access pctrie below * unless we checked that our object is swap and not * dead. */ atomic_thread_fence_acq(); if (object->type != OBJT_SWAP) goto next_obj; for (pi = 0; (sb = SWAP_PCTRIE_LOOKUP_GE( &object->un_pager.swp.swp_blks, pi)) != NULL; ) { pi = sb->p + SWAP_META_PAGES; for (i = 0; i < SWAP_META_PAGES; i++) { if (sb->d[i] == SWAPBLK_NONE) continue; if (swp_pager_isondev(sb->d[i], sp)) swp_pager_force_pagein(object, sb->p + i); } } next_obj: VM_OBJECT_WUNLOCK(object); mtx_lock(&vm_object_list_mtx); } mtx_unlock(&vm_object_list_mtx); if (sp->sw_used) { /* * Objects may be locked or paging to the device being * removed, so we will miss their pages and need to * make another pass. We have marked this device as * SW_CLOSING, so the activity should finish soon. */ retries++; if (retries > 100) { panic("swapoff: failed to locate %d swap blocks", sp->sw_used); } pause("swpoff", hz / 20); goto full_rescan; } EVENTHANDLER_INVOKE(swapoff, sp); } /************************************************************************ * SWAP META DATA * ************************************************************************ * * These routines manipulate the swap metadata stored in the * OBJT_SWAP object. * * Swap metadata is implemented with a global hash and not directly * linked into the object. Instead the object simply contains * appropriate tracking counters. */ /* * SWP_PAGER_SWBLK_EMPTY() - is a range of blocks free? */ static bool swp_pager_swblk_empty(struct swblk *sb, int start, int limit) { int i; MPASS(0 <= start && start <= limit && limit <= SWAP_META_PAGES); for (i = start; i < limit; i++) { if (sb->d[i] != SWAPBLK_NONE) return (false); } return (true); } /* * SWP_PAGER_META_BUILD() - add swap block to swap meta data for object * * We first convert the object to a swap object if it is a default * object. * * The specified swapblk is added to the object's swap metadata. If * the swapblk is not valid, it is freed instead. Any previously * assigned swapblk is returned. */ static daddr_t swp_pager_meta_build(vm_object_t object, vm_pindex_t pindex, daddr_t swapblk) { static volatile int swblk_zone_exhausted, swpctrie_zone_exhausted; struct swblk *sb, *sb1; vm_pindex_t modpi, rdpi; daddr_t prev_swapblk; int error, i; VM_OBJECT_ASSERT_WLOCKED(object); /* * Convert default object to swap object if necessary */ if (object->type != OBJT_SWAP) { pctrie_init(&object->un_pager.swp.swp_blks); /* * Ensure that swap_pager_swapoff()'s iteration over * object_list does not see a garbage pctrie. */ atomic_thread_fence_rel(); object->type = OBJT_SWAP; KASSERT(object->handle == NULL, ("default pager with handle")); } rdpi = rounddown(pindex, SWAP_META_PAGES); sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks, rdpi); if (sb == NULL) { if (swapblk == SWAPBLK_NONE) return (SWAPBLK_NONE); for (;;) { sb = uma_zalloc(swblk_zone, M_NOWAIT | (curproc == pageproc ? M_USE_RESERVE : 0)); if (sb != NULL) { sb->p = rdpi; for (i = 0; i < SWAP_META_PAGES; i++) sb->d[i] = SWAPBLK_NONE; if (atomic_cmpset_int(&swblk_zone_exhausted, 1, 0)) printf("swblk zone ok\n"); break; } VM_OBJECT_WUNLOCK(object); if (uma_zone_exhausted(swblk_zone)) { if (atomic_cmpset_int(&swblk_zone_exhausted, 0, 1)) printf("swap blk zone exhausted, " "increase kern.maxswzone\n"); vm_pageout_oom(VM_OOM_SWAPZ); pause("swzonxb", 10); } else uma_zwait(swblk_zone); VM_OBJECT_WLOCK(object); sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks, rdpi); if (sb != NULL) /* * Somebody swapped out a nearby page, * allocating swblk at the rdpi index, * while we dropped the object lock. */ goto allocated; } for (;;) { error = SWAP_PCTRIE_INSERT( &object->un_pager.swp.swp_blks, sb); if (error == 0) { if (atomic_cmpset_int(&swpctrie_zone_exhausted, 1, 0)) printf("swpctrie zone ok\n"); break; } VM_OBJECT_WUNLOCK(object); if (uma_zone_exhausted(swpctrie_zone)) { if (atomic_cmpset_int(&swpctrie_zone_exhausted, 0, 1)) printf("swap pctrie zone exhausted, " "increase kern.maxswzone\n"); vm_pageout_oom(VM_OOM_SWAPZ); pause("swzonxp", 10); } else uma_zwait(swpctrie_zone); VM_OBJECT_WLOCK(object); sb1 = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks, rdpi); if (sb1 != NULL) { uma_zfree(swblk_zone, sb); sb = sb1; goto allocated; } } } allocated: MPASS(sb->p == rdpi); modpi = pindex % SWAP_META_PAGES; /* Return prior contents of metadata. */ prev_swapblk = sb->d[modpi]; /* Enter block into metadata. */ sb->d[modpi] = swapblk; /* * Free the swblk if we end up with the empty page run. */ if (swapblk == SWAPBLK_NONE && swp_pager_swblk_empty(sb, 0, SWAP_META_PAGES)) { SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, rdpi); uma_zfree(swblk_zone, sb); } return (prev_swapblk); } /* * SWP_PAGER_META_FREE() - free a range of blocks in the object's swap metadata * * The requested range of blocks is freed, with any associated swap * returned to the swap bitmap. * * This routine will free swap metadata structures as they are cleaned * out. This routine does *NOT* operate on swap metadata associated * with resident pages. */ static void swp_pager_meta_free(vm_object_t object, vm_pindex_t pindex, vm_pindex_t count) { struct swblk *sb; daddr_t n_free, s_free; vm_pindex_t last; int i, limit, start; VM_OBJECT_ASSERT_WLOCKED(object); if (object->type != OBJT_SWAP || count == 0) return; swp_pager_init_freerange(&s_free, &n_free); last = pindex + count; for (;;) { sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks, rounddown(pindex, SWAP_META_PAGES)); if (sb == NULL || sb->p >= last) break; start = pindex > sb->p ? pindex - sb->p : 0; limit = last - sb->p < SWAP_META_PAGES ? last - sb->p : SWAP_META_PAGES; for (i = start; i < limit; i++) { if (sb->d[i] == SWAPBLK_NONE) continue; swp_pager_update_freerange(&s_free, &n_free, sb->d[i]); sb->d[i] = SWAPBLK_NONE; } if (swp_pager_swblk_empty(sb, 0, start) && swp_pager_swblk_empty(sb, limit, SWAP_META_PAGES)) { SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, sb->p); uma_zfree(swblk_zone, sb); } pindex = sb->p + SWAP_META_PAGES; } swp_pager_freeswapspace(s_free, n_free); } /* * SWP_PAGER_META_FREE_ALL() - destroy all swap metadata associated with object * * This routine locates and destroys all swap metadata associated with * an object. */ static void swp_pager_meta_free_all(vm_object_t object) { struct swblk *sb; daddr_t n_free, s_free; vm_pindex_t pindex; int i; VM_OBJECT_ASSERT_WLOCKED(object); if (object->type != OBJT_SWAP) return; swp_pager_init_freerange(&s_free, &n_free); for (pindex = 0; (sb = SWAP_PCTRIE_LOOKUP_GE( &object->un_pager.swp.swp_blks, pindex)) != NULL;) { pindex = sb->p + SWAP_META_PAGES; for (i = 0; i < SWAP_META_PAGES; i++) { if (sb->d[i] == SWAPBLK_NONE) continue; swp_pager_update_freerange(&s_free, &n_free, sb->d[i]); } SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, sb->p); uma_zfree(swblk_zone, sb); } swp_pager_freeswapspace(s_free, n_free); } /* * SWP_PAGER_METACTL() - misc control of swap meta data. * * This routine is capable of looking up, or removing swapblk * assignments in the swap meta data. It returns the swapblk being * looked-up, popped, or SWAPBLK_NONE if the block was invalid. * * When acting on a busy resident page and paging is in progress, we * have to wait until paging is complete but otherwise can act on the * busy page. * * SWM_POP remove from meta data but do not free it */ static daddr_t swp_pager_meta_ctl(vm_object_t object, vm_pindex_t pindex, int flags) { struct swblk *sb; daddr_t r1; if ((flags & SWM_POP) != 0) VM_OBJECT_ASSERT_WLOCKED(object); else VM_OBJECT_ASSERT_LOCKED(object); /* * The meta data only exists if the object is OBJT_SWAP * and even then might not be allocated yet. */ if (object->type != OBJT_SWAP) return (SWAPBLK_NONE); sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks, rounddown(pindex, SWAP_META_PAGES)); if (sb == NULL) return (SWAPBLK_NONE); r1 = sb->d[pindex % SWAP_META_PAGES]; if (r1 == SWAPBLK_NONE) return (SWAPBLK_NONE); if ((flags & SWM_POP) != 0) { sb->d[pindex % SWAP_META_PAGES] = SWAPBLK_NONE; if (swp_pager_swblk_empty(sb, 0, SWAP_META_PAGES)) { SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, rounddown(pindex, SWAP_META_PAGES)); uma_zfree(swblk_zone, sb); } } return (r1); } /* * Returns the least page index which is greater than or equal to the * parameter pindex and for which there is a swap block allocated. * Returns object's size if the object's type is not swap or if there * are no allocated swap blocks for the object after the requested * pindex. */ vm_pindex_t swap_pager_find_least(vm_object_t object, vm_pindex_t pindex) { struct swblk *sb; int i; VM_OBJECT_ASSERT_LOCKED(object); if (object->type != OBJT_SWAP) return (object->size); sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks, rounddown(pindex, SWAP_META_PAGES)); if (sb == NULL) return (object->size); if (sb->p < pindex) { for (i = pindex % SWAP_META_PAGES; i < SWAP_META_PAGES; i++) { if (sb->d[i] != SWAPBLK_NONE) return (sb->p + i); } sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks, roundup(pindex, SWAP_META_PAGES)); if (sb == NULL) return (object->size); } for (i = 0; i < SWAP_META_PAGES; i++) { if (sb->d[i] != SWAPBLK_NONE) return (sb->p + i); } /* * We get here if a swblk is present in the trie but it * doesn't map any blocks. */ MPASS(0); return (object->size); } /* * System call swapon(name) enables swapping on device name, * which must be in the swdevsw. Return EBUSY * if already swapping on this device. */ #ifndef _SYS_SYSPROTO_H_ struct swapon_args { char *name; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sys_swapon(struct thread *td, struct swapon_args *uap) { struct vattr attr; struct vnode *vp; struct nameidata nd; int error; error = priv_check(td, PRIV_SWAPON); if (error) return (error); sx_xlock(&swdev_syscall_lock); /* * Swap metadata may not fit in the KVM if we have physical * memory of >1GB. */ if (swblk_zone == NULL) { error = ENOMEM; goto done; } NDINIT(&nd, LOOKUP, ISOPEN | FOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->name, td); error = namei(&nd); if (error) goto done; NDFREE(&nd, NDF_ONLY_PNBUF); vp = nd.ni_vp; if (vn_isdisk(vp, &error)) { error = swapongeom(vp); } else if (vp->v_type == VREG && (vp->v_mount->mnt_vfc->vfc_flags & VFCF_NETWORK) != 0 && (error = VOP_GETATTR(vp, &attr, td->td_ucred)) == 0) { /* * Allow direct swapping to NFS regular files in the same * way that nfs_mountroot() sets up diskless swapping. */ error = swaponvp(td, vp, attr.va_size / DEV_BSIZE); } if (error) vrele(vp); done: sx_xunlock(&swdev_syscall_lock); return (error); } /* * Check that the total amount of swap currently configured does not * exceed half the theoretical maximum. If it does, print a warning * message. */ static void swapon_check_swzone(void) { unsigned long maxpages, npages; - npages = swap_total / PAGE_SIZE; + npages = swap_total; /* absolute maximum we can handle assuming 100% efficiency */ maxpages = uma_zone_get_max(swblk_zone) * SWAP_META_PAGES; /* recommend using no more than half that amount */ if (npages > maxpages / 2) { printf("warning: total configured swap (%lu pages) " "exceeds maximum recommended amount (%lu pages).\n", npages, maxpages / 2); printf("warning: increase kern.maxswzone " "or reduce amount of swap.\n"); } } static void swaponsomething(struct vnode *vp, void *id, u_long nblks, sw_strategy_t *strategy, sw_close_t *close, dev_t dev, int flags) { struct swdevt *sp, *tsp; swblk_t dvbase; u_long mblocks; /* * nblks is in DEV_BSIZE'd chunks, convert to PAGE_SIZE'd chunks. * First chop nblks off to page-align it, then convert. * * sw->sw_nblks is in page-sized chunks now too. */ nblks &= ~(ctodb(1) - 1); nblks = dbtoc(nblks); /* * If we go beyond this, we get overflows in the radix * tree bitmap code. */ mblocks = 0x40000000 / BLIST_META_RADIX; if (nblks > mblocks) { printf( "WARNING: reducing swap size to maximum of %luMB per unit\n", mblocks / 1024 / 1024 * PAGE_SIZE); nblks = mblocks; } sp = malloc(sizeof *sp, M_VMPGDATA, M_WAITOK | M_ZERO); sp->sw_vp = vp; sp->sw_id = id; sp->sw_dev = dev; sp->sw_flags = 0; sp->sw_nblks = nblks; sp->sw_used = 0; sp->sw_strategy = strategy; sp->sw_close = close; sp->sw_flags = flags; sp->sw_blist = blist_create(nblks, M_WAITOK); /* * Do not free the first two block in order to avoid overwriting * any bsd label at the front of the partition */ blist_free(sp->sw_blist, 2, nblks - 2); dvbase = 0; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(tsp, &swtailq, sw_list) { if (tsp->sw_end >= dvbase) { /* * We put one uncovered page between the devices * in order to definitively prevent any cross-device * I/O requests */ dvbase = tsp->sw_end + 1; } } sp->sw_first = dvbase; sp->sw_end = dvbase + nblks; TAILQ_INSERT_TAIL(&swtailq, sp, sw_list); nswapdev++; swap_pager_avail += nblks - 2; - swap_total += (vm_ooffset_t)nblks * PAGE_SIZE; + swap_total += nblks; swapon_check_swzone(); swp_sizecheck(); mtx_unlock(&sw_dev_mtx); EVENTHANDLER_INVOKE(swapon, sp); } /* * SYSCALL: swapoff(devname) * * Disable swapping on the given device. * * XXX: Badly designed system call: it should use a device index * rather than filename as specification. We keep sw_vp around * only to make this work. */ #ifndef _SYS_SYSPROTO_H_ struct swapoff_args { char *name; }; #endif /* * MPSAFE */ /* ARGSUSED */ int sys_swapoff(struct thread *td, struct swapoff_args *uap) { struct vnode *vp; struct nameidata nd; struct swdevt *sp; int error; error = priv_check(td, PRIV_SWAPOFF); if (error) return (error); sx_xlock(&swdev_syscall_lock); NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->name, td); error = namei(&nd); if (error) goto done; NDFREE(&nd, NDF_ONLY_PNBUF); vp = nd.ni_vp; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (sp->sw_vp == vp) break; } mtx_unlock(&sw_dev_mtx); if (sp == NULL) { error = EINVAL; goto done; } error = swapoff_one(sp, td->td_ucred); done: sx_xunlock(&swdev_syscall_lock); return (error); } static int swapoff_one(struct swdevt *sp, struct ucred *cred) { u_long nblks; #ifdef MAC int error; #endif sx_assert(&swdev_syscall_lock, SA_XLOCKED); #ifdef MAC (void) vn_lock(sp->sw_vp, LK_EXCLUSIVE | LK_RETRY); error = mac_system_check_swapoff(cred, sp->sw_vp); (void) VOP_UNLOCK(sp->sw_vp, 0); if (error != 0) return (error); #endif nblks = sp->sw_nblks; /* * We can turn off this swap device safely only if the * available virtual memory in the system will fit the amount * of data we will have to page back in, plus an epsilon so * the system doesn't become critically low on swap space. */ if (vm_free_count() + swap_pager_avail < nblks + nswap_lowat) return (ENOMEM); /* * Prevent further allocations on this device. */ mtx_lock(&sw_dev_mtx); sp->sw_flags |= SW_CLOSING; swap_pager_avail -= blist_fill(sp->sw_blist, 0, nblks); - swap_total -= (vm_ooffset_t)nblks * PAGE_SIZE; + swap_total -= nblks; mtx_unlock(&sw_dev_mtx); /* * Page in the contents of the device and close it. */ swap_pager_swapoff(sp); sp->sw_close(curthread, sp); mtx_lock(&sw_dev_mtx); sp->sw_id = NULL; TAILQ_REMOVE(&swtailq, sp, sw_list); nswapdev--; if (nswapdev == 0) { swap_pager_full = 2; swap_pager_almost_full = 1; } if (swdevhd == sp) swdevhd = NULL; mtx_unlock(&sw_dev_mtx); blist_destroy(sp->sw_blist); free(sp, M_VMPGDATA); return (0); } void swapoff_all(void) { struct swdevt *sp, *spt; const char *devname; int error; sx_xlock(&swdev_syscall_lock); mtx_lock(&sw_dev_mtx); TAILQ_FOREACH_SAFE(sp, &swtailq, sw_list, spt) { mtx_unlock(&sw_dev_mtx); if (vn_isdisk(sp->sw_vp, NULL)) devname = devtoname(sp->sw_vp->v_rdev); else devname = "[file]"; error = swapoff_one(sp, thread0.td_ucred); if (error != 0) { printf("Cannot remove swap device %s (error=%d), " "skipping.\n", devname, error); } else if (bootverbose) { printf("Swap device %s removed.\n", devname); } mtx_lock(&sw_dev_mtx); } mtx_unlock(&sw_dev_mtx); sx_xunlock(&swdev_syscall_lock); } void swap_pager_status(int *total, int *used) { struct swdevt *sp; *total = 0; *used = 0; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { *total += sp->sw_nblks; *used += sp->sw_used; } mtx_unlock(&sw_dev_mtx); } int swap_dev_info(int name, struct xswdev *xs, char *devname, size_t len) { struct swdevt *sp; const char *tmp_devname; int error, n; n = 0; error = ENOENT; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (n != name) { n++; continue; } xs->xsw_version = XSWDEV_VERSION; xs->xsw_dev = sp->sw_dev; xs->xsw_flags = sp->sw_flags; xs->xsw_nblks = sp->sw_nblks; xs->xsw_used = sp->sw_used; if (devname != NULL) { if (vn_isdisk(sp->sw_vp, NULL)) tmp_devname = devtoname(sp->sw_vp->v_rdev); else tmp_devname = "[file]"; strncpy(devname, tmp_devname, len); } error = 0; break; } mtx_unlock(&sw_dev_mtx); return (error); } #if defined(COMPAT_FREEBSD11) #define XSWDEV_VERSION_11 1 struct xswdev11 { u_int xsw_version; uint32_t xsw_dev; int xsw_flags; int xsw_nblks; int xsw_used; }; #endif static int sysctl_vm_swap_info(SYSCTL_HANDLER_ARGS) { struct xswdev xs; #if defined(COMPAT_FREEBSD11) struct xswdev11 xs11; #endif int error; if (arg2 != 1) /* name length */ return (EINVAL); error = swap_dev_info(*(int *)arg1, &xs, NULL, 0); if (error != 0) return (error); #if defined(COMPAT_FREEBSD11) if (req->oldlen == sizeof(xs11)) { xs11.xsw_version = XSWDEV_VERSION_11; xs11.xsw_dev = xs.xsw_dev; /* truncation */ xs11.xsw_flags = xs.xsw_flags; xs11.xsw_nblks = xs.xsw_nblks; xs11.xsw_used = xs.xsw_used; error = SYSCTL_OUT(req, &xs11, sizeof(xs11)); } else #endif error = SYSCTL_OUT(req, &xs, sizeof(xs)); return (error); } SYSCTL_INT(_vm, OID_AUTO, nswapdev, CTLFLAG_RD, &nswapdev, 0, "Number of swap devices"); SYSCTL_NODE(_vm, OID_AUTO, swap_info, CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_vm_swap_info, "Swap statistics by device"); /* * Count the approximate swap usage in pages for a vmspace. The * shadowed or not yet copied on write swap blocks are not accounted. * The map must be locked. */ long vmspace_swap_count(struct vmspace *vmspace) { vm_map_t map; vm_map_entry_t cur; vm_object_t object; struct swblk *sb; vm_pindex_t e, pi; long count; int i; map = &vmspace->vm_map; count = 0; for (cur = map->header.next; cur != &map->header; cur = cur->next) { if ((cur->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) continue; object = cur->object.vm_object; if (object == NULL || object->type != OBJT_SWAP) continue; VM_OBJECT_RLOCK(object); if (object->type != OBJT_SWAP) goto unlock; pi = OFF_TO_IDX(cur->offset); e = pi + OFF_TO_IDX(cur->end - cur->start); for (;; pi = sb->p + SWAP_META_PAGES) { sb = SWAP_PCTRIE_LOOKUP_GE( &object->un_pager.swp.swp_blks, pi); if (sb == NULL || sb->p >= e) break; for (i = 0; i < SWAP_META_PAGES; i++) { if (sb->p + i < e && sb->d[i] != SWAPBLK_NONE) count++; } } unlock: VM_OBJECT_RUNLOCK(object); } return (count); } /* * GEOM backend * * Swapping onto disk devices. * */ static g_orphan_t swapgeom_orphan; static struct g_class g_swap_class = { .name = "SWAP", .version = G_VERSION, .orphan = swapgeom_orphan, }; DECLARE_GEOM_CLASS(g_swap_class, g_class); static void swapgeom_close_ev(void *arg, int flags) { struct g_consumer *cp; cp = arg; g_access(cp, -1, -1, 0); g_detach(cp); g_destroy_consumer(cp); } /* * Add a reference to the g_consumer for an inflight transaction. */ static void swapgeom_acquire(struct g_consumer *cp) { mtx_assert(&sw_dev_mtx, MA_OWNED); cp->index++; } /* * Remove a reference from the g_consumer. Post a close event if all * references go away, since the function might be called from the * biodone context. */ static void swapgeom_release(struct g_consumer *cp, struct swdevt *sp) { mtx_assert(&sw_dev_mtx, MA_OWNED); cp->index--; if (cp->index == 0) { if (g_post_event(swapgeom_close_ev, cp, M_NOWAIT, NULL) == 0) sp->sw_id = NULL; } } static void swapgeom_done(struct bio *bp2) { struct swdevt *sp; struct buf *bp; struct g_consumer *cp; bp = bp2->bio_caller2; cp = bp2->bio_from; bp->b_ioflags = bp2->bio_flags; if (bp2->bio_error) bp->b_ioflags |= BIO_ERROR; bp->b_resid = bp->b_bcount - bp2->bio_completed; bp->b_error = bp2->bio_error; bufdone(bp); sp = bp2->bio_caller1; mtx_lock(&sw_dev_mtx); swapgeom_release(cp, sp); mtx_unlock(&sw_dev_mtx); g_destroy_bio(bp2); } static void swapgeom_strategy(struct buf *bp, struct swdevt *sp) { struct bio *bio; struct g_consumer *cp; mtx_lock(&sw_dev_mtx); cp = sp->sw_id; if (cp == NULL) { mtx_unlock(&sw_dev_mtx); bp->b_error = ENXIO; bp->b_ioflags |= BIO_ERROR; bufdone(bp); return; } swapgeom_acquire(cp); mtx_unlock(&sw_dev_mtx); if (bp->b_iocmd == BIO_WRITE) bio = g_new_bio(); else bio = g_alloc_bio(); if (bio == NULL) { mtx_lock(&sw_dev_mtx); swapgeom_release(cp, sp); mtx_unlock(&sw_dev_mtx); bp->b_error = ENOMEM; bp->b_ioflags |= BIO_ERROR; bufdone(bp); return; } bio->bio_caller1 = sp; bio->bio_caller2 = bp; bio->bio_cmd = bp->b_iocmd; bio->bio_offset = (bp->b_blkno - sp->sw_first) * PAGE_SIZE; bio->bio_length = bp->b_bcount; bio->bio_done = swapgeom_done; if (!buf_mapped(bp)) { bio->bio_ma = bp->b_pages; bio->bio_data = unmapped_buf; bio->bio_ma_offset = (vm_offset_t)bp->b_offset & PAGE_MASK; bio->bio_ma_n = bp->b_npages; bio->bio_flags |= BIO_UNMAPPED; } else { bio->bio_data = bp->b_data; bio->bio_ma = NULL; } g_io_request(bio, cp); return; } static void swapgeom_orphan(struct g_consumer *cp) { struct swdevt *sp; int destroy; mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (sp->sw_id == cp) { sp->sw_flags |= SW_CLOSING; break; } } /* * Drop reference we were created with. Do directly since we're in a * special context where we don't have to queue the call to * swapgeom_close_ev(). */ cp->index--; destroy = ((sp != NULL) && (cp->index == 0)); if (destroy) sp->sw_id = NULL; mtx_unlock(&sw_dev_mtx); if (destroy) swapgeom_close_ev(cp, 0); } static void swapgeom_close(struct thread *td, struct swdevt *sw) { struct g_consumer *cp; mtx_lock(&sw_dev_mtx); cp = sw->sw_id; sw->sw_id = NULL; mtx_unlock(&sw_dev_mtx); /* * swapgeom_close() may be called from the biodone context, * where we cannot perform topology changes. Delegate the * work to the events thread. */ if (cp != NULL) g_waitfor_event(swapgeom_close_ev, cp, M_WAITOK, NULL); } static int swapongeom_locked(struct cdev *dev, struct vnode *vp) { struct g_provider *pp; struct g_consumer *cp; static struct g_geom *gp; struct swdevt *sp; u_long nblks; int error; pp = g_dev_getprovider(dev); if (pp == NULL) return (ENODEV); mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { cp = sp->sw_id; if (cp != NULL && cp->provider == pp) { mtx_unlock(&sw_dev_mtx); return (EBUSY); } } mtx_unlock(&sw_dev_mtx); if (gp == NULL) gp = g_new_geomf(&g_swap_class, "swap"); cp = g_new_consumer(gp); cp->index = 1; /* Number of active I/Os, plus one for being active. */ cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE; g_attach(cp, pp); /* * XXX: Every time you think you can improve the margin for * footshooting, somebody depends on the ability to do so: * savecore(8) wants to write to our swapdev so we cannot * set an exclusive count :-( */ error = g_access(cp, 1, 1, 0); if (error != 0) { g_detach(cp); g_destroy_consumer(cp); return (error); } nblks = pp->mediasize / DEV_BSIZE; swaponsomething(vp, cp, nblks, swapgeom_strategy, swapgeom_close, dev2udev(dev), (pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 ? SW_UNMAPPED : 0); return (0); } static int swapongeom(struct vnode *vp) { int error; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (vp->v_type != VCHR || (vp->v_iflag & VI_DOOMED) != 0) { error = ENOENT; } else { g_topology_lock(); error = swapongeom_locked(vp->v_rdev, vp); g_topology_unlock(); } VOP_UNLOCK(vp, 0); return (error); } /* * VNODE backend * * This is used mainly for network filesystem (read: probably only tested * with NFS) swapfiles. * */ static void swapdev_strategy(struct buf *bp, struct swdevt *sp) { struct vnode *vp2; bp->b_blkno = ctodb(bp->b_blkno - sp->sw_first); vp2 = sp->sw_id; vhold(vp2); if (bp->b_iocmd == BIO_WRITE) { if (bp->b_bufobj) bufobj_wdrop(bp->b_bufobj); bufobj_wref(&vp2->v_bufobj); } if (bp->b_bufobj != &vp2->v_bufobj) bp->b_bufobj = &vp2->v_bufobj; bp->b_vp = vp2; bp->b_iooffset = dbtob(bp->b_blkno); bstrategy(bp); return; } static void swapdev_close(struct thread *td, struct swdevt *sp) { VOP_CLOSE(sp->sw_vp, FREAD | FWRITE, td->td_ucred, td); vrele(sp->sw_vp); } static int swaponvp(struct thread *td, struct vnode *vp, u_long nblks) { struct swdevt *sp; int error; if (nblks == 0) return (ENXIO); mtx_lock(&sw_dev_mtx); TAILQ_FOREACH(sp, &swtailq, sw_list) { if (sp->sw_id == vp) { mtx_unlock(&sw_dev_mtx); return (EBUSY); } } mtx_unlock(&sw_dev_mtx); (void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); #ifdef MAC error = mac_system_check_swapon(td->td_ucred, vp); if (error == 0) #endif error = VOP_OPEN(vp, FREAD | FWRITE, td->td_ucred, td, NULL); (void) VOP_UNLOCK(vp, 0); if (error) return (error); swaponsomething(vp, vp, nblks, swapdev_strategy, swapdev_close, NODEV, 0); return (0); } static int sysctl_swap_async_max(SYSCTL_HANDLER_ARGS) { int error, new, n; new = nsw_wcount_async_max; error = sysctl_handle_int(oidp, &new, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (new > nswbuf / 2 || new < 1) return (EINVAL); mtx_lock(&pbuf_mtx); while (nsw_wcount_async_max != new) { /* * Adjust difference. If the current async count is too low, * we will need to sqeeze our update slowly in. Sleep with a * higher priority than getpbuf() to finish faster. */ n = new - nsw_wcount_async_max; if (nsw_wcount_async + n >= 0) { nsw_wcount_async += n; nsw_wcount_async_max += n; wakeup(&nsw_wcount_async); } else { nsw_wcount_async_max -= nsw_wcount_async; nsw_wcount_async = 0; msleep(&nsw_wcount_async, &pbuf_mtx, PSWP, "swpsysctl", 0); } } mtx_unlock(&pbuf_mtx); return (0); }