/* * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * 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. * * from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. * * $FreeBSD$ */ #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 extern int maxslp; /* * System initialization * * Note: proc0 from proc.h */ static void vm_init_limits(void *); SYSINIT(vm_limits, SI_SUB_VM_CONF, SI_ORDER_FIRST, vm_init_limits, &proc0) /* * THIS MUST BE THE LAST INITIALIZATION ITEM!!! * * Note: run scheduling should be divorced from the vm system. */ static void scheduler(void *); SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL) #ifndef NO_SWAPPING static void swapout(struct proc *); static void vm_proc_swapin(struct proc *p); static void vm_proc_swapout(struct proc *p); #endif /* * MPSAFE */ int kernacc(addr, len, rw) caddr_t addr; int len, rw; { boolean_t rv; vm_offset_t saddr, eaddr; vm_prot_t prot; KASSERT((rw & ~VM_PROT_ALL) == 0, ("illegal ``rw'' argument to kernacc (%x)\n", rw)); prot = rw; saddr = trunc_page((vm_offset_t)addr); eaddr = round_page((vm_offset_t)addr + len); rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); return (rv == TRUE); } /* * MPSAFE */ int useracc(addr, len, rw) caddr_t addr; int len, rw; { boolean_t rv; vm_prot_t prot; KASSERT((rw & ~VM_PROT_ALL) == 0, ("illegal ``rw'' argument to useracc (%x)\n", rw)); prot = rw; /* * XXX - check separately to disallow access to user area and user * page tables - they are in the map. * * XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once * only used (as an end address) in trap.c. Use it as an end address * here too. This bogusness has spread. I just fixed where it was * used as a max in vm_mmap.c. */ if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS || (vm_offset_t) addr + len < (vm_offset_t) addr) { return (FALSE); } rv = vm_map_check_protection(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), prot); return (rv == TRUE); } /* * MPSAFE */ void vslock(addr, len) caddr_t addr; u_int len; { vm_map_wire(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), FALSE); } /* * MPSAFE */ void vsunlock(addr, len) caddr_t addr; u_int len; { vm_map_unwire(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), FALSE); } /* * Create the U area for a new process. * This routine directly affects the fork perf for a process. */ void vm_proc_new(struct proc *p) { vm_page_t ma[UAREA_PAGES]; vm_object_t upobj; vm_offset_t up; vm_page_t m; u_int i; /* * Allocate object for the upage. */ upobj = vm_object_allocate(OBJT_DEFAULT, UAREA_PAGES); p->p_upages_obj = upobj; /* * Get a kernel virtual address for the U area for this process. */ up = kmem_alloc_nofault(kernel_map, UAREA_PAGES * PAGE_SIZE); if (up == 0) panic("vm_proc_new: upage allocation failed"); p->p_uarea = (struct user *)up; for (i = 0; i < UAREA_PAGES; i++) { /* * Get a uarea page. */ m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY | VM_ALLOC_WIRED); ma[i] = m; vm_page_wakeup(m); vm_page_flag_clear(m, PG_ZERO); m->valid = VM_PAGE_BITS_ALL; } /* * Enter the pages into the kernel address space. */ pmap_qenter(up, ma, UAREA_PAGES); } /* * Dispose the U area for a process that has exited. * This routine directly impacts the exit perf of a process. * XXX proc_zone is marked UMA_ZONE_NOFREE, so this should never be called. */ void vm_proc_dispose(struct proc *p) { vm_object_t upobj; vm_offset_t up; vm_page_t m; upobj = p->p_upages_obj; if (upobj->resident_page_count != UAREA_PAGES) panic("vm_proc_dispose: incorrect number of pages in upobj"); vm_page_lock_queues(); while ((m = TAILQ_FIRST(&upobj->memq)) != NULL) { vm_page_busy(m); vm_page_unwire(m, 0); vm_page_free(m); } vm_page_unlock_queues(); up = (vm_offset_t)p->p_uarea; pmap_qremove(up, UAREA_PAGES); kmem_free(kernel_map, up, UAREA_PAGES * PAGE_SIZE); vm_object_deallocate(upobj); } #ifndef NO_SWAPPING /* * Allow the U area for a process to be prejudicially paged out. */ void vm_proc_swapout(struct proc *p) { vm_object_t upobj; vm_offset_t up; vm_page_t m; upobj = p->p_upages_obj; if (upobj->resident_page_count != UAREA_PAGES) panic("vm_proc_dispose: incorrect number of pages in upobj"); vm_page_lock_queues(); TAILQ_FOREACH(m, &upobj->memq, listq) { vm_page_dirty(m); vm_page_unwire(m, 0); } vm_page_unlock_queues(); up = (vm_offset_t)p->p_uarea; pmap_qremove(up, UAREA_PAGES); } /* * Bring the U area for a specified process back in. */ void vm_proc_swapin(struct proc *p) { vm_page_t ma[UAREA_PAGES]; vm_object_t upobj; vm_offset_t up; vm_page_t m; int rv; int i; upobj = p->p_upages_obj; for (i = 0; i < UAREA_PAGES; i++) { m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY); if (m->valid != VM_PAGE_BITS_ALL) { rv = vm_pager_get_pages(upobj, &m, 1, 0); if (rv != VM_PAGER_OK) panic("vm_proc_swapin: cannot get upage"); } ma[i] = m; } if (upobj->resident_page_count != UAREA_PAGES) panic("vm_proc_swapin: lost pages from upobj"); vm_page_lock_queues(); TAILQ_FOREACH(m, &upobj->memq, listq) { m->valid = VM_PAGE_BITS_ALL; vm_page_wire(m); vm_page_wakeup(m); } vm_page_unlock_queues(); up = (vm_offset_t)p->p_uarea; pmap_qenter(up, ma, UAREA_PAGES); } #endif /* * Implement fork's actions on an address space. * Here we arrange for the address space to be copied or referenced, * allocate a user struct (pcb and kernel stack), then call the * machine-dependent layer to fill those in and make the new process * ready to run. The new process is set up so that it returns directly * to user mode to avoid stack copying and relocation problems. */ void vm_forkproc(td, p2, td2, flags) struct thread *td; struct proc *p2; struct thread *td2; int flags; { struct proc *p1 = td->td_proc; struct user *up; GIANT_REQUIRED; if ((flags & RFPROC) == 0) { /* * Divorce the memory, if it is shared, essentially * this changes shared memory amongst threads, into * COW locally. */ if ((flags & RFMEM) == 0) { if (p1->p_vmspace->vm_refcnt > 1) { vmspace_unshare(p1); } } cpu_fork(td, p2, td2, flags); return; } if (flags & RFMEM) { p2->p_vmspace = p1->p_vmspace; p1->p_vmspace->vm_refcnt++; } while (vm_page_count_severe()) { VM_WAIT; } if ((flags & RFMEM) == 0) { p2->p_vmspace = vmspace_fork(p1->p_vmspace); pmap_pinit2(vmspace_pmap(p2->p_vmspace)); if (p1->p_vmspace->vm_shm) shmfork(p1, p2); } /* XXXKSE this is unsatisfactory but should be adequate */ up = p2->p_uarea; /* * p_stats currently points at fields in the user struct * but not at &u, instead at p_addr. Copy parts of * p_stats; zero the rest of p_stats (statistics). * * If procsig->ps_refcnt is 1 and p2->p_sigacts is NULL we dont' need * to share sigacts, so we use the up->u_sigacts. */ p2->p_stats = &up->u_stats; if (p2->p_sigacts == NULL) { if (p2->p_procsig->ps_refcnt != 1) printf ("PID:%d NULL sigacts with refcnt not 1!\n",p2->p_pid); p2->p_sigacts = &up->u_sigacts; up->u_sigacts = *p1->p_sigacts; } bzero(&up->u_stats.pstat_startzero, (unsigned) ((caddr_t) &up->u_stats.pstat_endzero - (caddr_t) &up->u_stats.pstat_startzero)); bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy, ((caddr_t) &up->u_stats.pstat_endcopy - (caddr_t) &up->u_stats.pstat_startcopy)); /* * cpu_fork will copy and update the pcb, set up the kernel stack, * and make the child ready to run. */ cpu_fork(td, p2, td2, flags); } /* * Called after process has been wait(2)'ed apon and is being reaped. * The idea is to reclaim resources that we could not reclaim while * the process was still executing. */ void vm_waitproc(p) struct proc *p; { struct thread *td; GIANT_REQUIRED; cpu_wait(p); /* XXXKSE by here there should not be any threads left! */ FOREACH_THREAD_IN_PROC(p, td) { panic("vm_waitproc: Survivor thread!"); } vmspace_exitfree(p); /* and clean-out the vmspace */ } /* * Set default limits for VM system. * Called for proc 0, and then inherited by all others. * * XXX should probably act directly on proc0. */ static void vm_init_limits(udata) void *udata; { struct proc *p = udata; int rss_limit; /* * Set up the initial limits on process VM. Set the maximum resident * set size to be half of (reasonably) available memory. Since this * is a soft limit, it comes into effect only when the system is out * of memory - half of main memory helps to favor smaller processes, * and reduces thrashing of the object cache. */ p->p_rlimit[RLIMIT_STACK].rlim_cur = dflssiz; p->p_rlimit[RLIMIT_STACK].rlim_max = maxssiz; p->p_rlimit[RLIMIT_DATA].rlim_cur = dfldsiz; p->p_rlimit[RLIMIT_DATA].rlim_max = maxdsiz; /* limit the limit to no less than 2MB */ rss_limit = max(cnt.v_free_count, 512); p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit); p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY; } void faultin(p) struct proc *p; { GIANT_REQUIRED; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_assert(&sched_lock, MA_OWNED); #ifdef NO_SWAPPING if ((p->p_sflag & PS_INMEM) == 0) panic("faultin: proc swapped out with NO_SWAPPING!"); #else if ((p->p_sflag & PS_INMEM) == 0) { struct thread *td; ++p->p_lock; /* * If another process is swapping in this process, * just wait until it finishes. */ if (p->p_sflag & PS_SWAPPINGIN) { mtx_unlock_spin(&sched_lock); msleep(&p->p_sflag, &p->p_mtx, PVM, "faultin", 0); mtx_lock_spin(&sched_lock); --p->p_lock; return; } p->p_sflag |= PS_SWAPPINGIN; mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); vm_proc_swapin(p); FOREACH_THREAD_IN_PROC (p, td) pmap_swapin_thread(td); PROC_LOCK(p); mtx_lock_spin(&sched_lock); p->p_sflag &= ~PS_SWAPPINGIN; p->p_sflag |= PS_INMEM; FOREACH_THREAD_IN_PROC (p, td) if (td->td_state == TDS_SWAPPED) setrunqueue(td); wakeup(&p->p_sflag); /* undo the effect of setting SLOCK above */ --p->p_lock; } #endif } /* * This swapin algorithm attempts to swap-in processes only if there * is enough space for them. Of course, if a process waits for a long * time, it will be swapped in anyway. * * XXXKSE - process with the thread with highest priority counts.. * * Giant is still held at this point, to be released in tsleep. */ /* ARGSUSED*/ static void scheduler(dummy) void *dummy; { struct proc *p; struct thread *td; int pri; struct proc *pp; int ppri; mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED); /* GIANT_REQUIRED */ loop: if (vm_page_count_min()) { VM_WAIT; goto loop; } pp = NULL; ppri = INT_MIN; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { struct ksegrp *kg; if (p->p_sflag & (PS_INMEM | PS_SWAPPING | PS_SWAPPINGIN)) { continue; } mtx_lock_spin(&sched_lock); FOREACH_THREAD_IN_PROC(p, td) { /* * A runnable thread of a process swapped out is in * TDS_SWAPPED. */ if (td->td_state == TDS_SWAPPED) { kg = td->td_ksegrp; pri = p->p_swtime + kg->kg_slptime; if ((p->p_sflag & PS_SWAPINREQ) == 0) { pri -= kg->kg_nice * 8; } /* * if this ksegrp is higher priority * and there is enough space, then select * this process instead of the previous * selection. */ if (pri > ppri) { pp = p; ppri = pri; } } } mtx_unlock_spin(&sched_lock); } sx_sunlock(&allproc_lock); /* * Nothing to do, back to sleep. */ if ((p = pp) == NULL) { tsleep(&proc0, PVM, "sched", maxslp * hz / 2); goto loop; } PROC_LOCK(p); mtx_lock_spin(&sched_lock); /* * Another process may be bringing or may have already * brought this process in while we traverse all threads. * Or, this process may even be being swapped out again. */ if (p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) { mtx_unlock_spin(&sched_lock); PROC_UNLOCK(p); goto loop; } p->p_sflag &= ~PS_SWAPINREQ; /* * We would like to bring someone in. (only if there is space). * [What checks the space? ] */ faultin(p); PROC_UNLOCK(p); p->p_swtime = 0; mtx_unlock_spin(&sched_lock); goto loop; } #ifndef NO_SWAPPING /* * Swap_idle_threshold1 is the guaranteed swapped in time for a process */ static int swap_idle_threshold1 = 2; SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold1, CTLFLAG_RW, &swap_idle_threshold1, 0, ""); /* * Swap_idle_threshold2 is the time that a process can be idle before * it will be swapped out, if idle swapping is enabled. */ static int swap_idle_threshold2 = 10; SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold2, CTLFLAG_RW, &swap_idle_threshold2, 0, ""); /* * Swapout is driven by the pageout daemon. Very simple, we find eligible * procs and unwire their u-areas. We try to always "swap" at least one * process in case we need the room for a swapin. * If any procs have been sleeping/stopped for at least maxslp seconds, * they are swapped. Else, we swap the longest-sleeping or stopped process, * if any, otherwise the longest-resident process. */ void swapout_procs(action) int action; { struct proc *p; struct thread *td; struct ksegrp *kg; struct proc *outp, *outp2; int outpri, outpri2; int didswap = 0; GIANT_REQUIRED; outp = outp2 = NULL; outpri = outpri2 = INT_MIN; retry: sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { struct vmspace *vm; int minslptime = 100000; /* * Do not swapout a process that * is waiting for VM data * structures there is a possible * deadlock. Test this first as * this may block. * * Lock the map until swapout * finishes, or a thread of this * process may attempt to alter * the map. */ vm = p->p_vmspace; ++vm->vm_refcnt; if (!vm_map_trylock(&vm->vm_map)) goto nextproc1; PROC_LOCK(p); if (p->p_lock != 0 || (p->p_flag & (P_STOPPED_SNGL|P_TRACED|P_SYSTEM|P_WEXIT)) != 0) { goto nextproc2; } /* * only aiod changes vmspace, however it will be * skipped because of the if statement above checking * for P_SYSTEM */ mtx_lock_spin(&sched_lock); if ((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) != PS_INMEM) goto nextproc; switch (p->p_state) { default: /* Don't swap out processes in any sort * of 'special' state. */ goto nextproc; case PRS_NORMAL: /* * do not swapout a realtime process * Check all the thread groups.. */ FOREACH_KSEGRP_IN_PROC(p, kg) { if (PRI_IS_REALTIME(kg->kg_pri_class)) goto nextproc; /* * Guarantee swap_idle_threshold1 * time in memory. */ if (kg->kg_slptime < swap_idle_threshold1) goto nextproc; /* * Do not swapout a process if it is * waiting on a critical event of some * kind or there is a thread whose * pageable memory may be accessed. * * This could be refined to support * swapping out a thread. */ FOREACH_THREAD_IN_GROUP(kg, td) { if ((td->td_priority) < PSOCK || !thread_safetoswapout(td)) goto nextproc; } /* * If the system is under memory stress, * or if we are swapping * idle processes >= swap_idle_threshold2, * then swap the process out. */ if (((action & VM_SWAP_NORMAL) == 0) && (((action & VM_SWAP_IDLE) == 0) || (kg->kg_slptime < swap_idle_threshold2))) goto nextproc; if (minslptime > kg->kg_slptime) minslptime = kg->kg_slptime; } /* * If the process has been asleep for awhile and had * most of its pages taken away already, swap it out. */ if ((action & VM_SWAP_NORMAL) || ((action & VM_SWAP_IDLE) && (minslptime > swap_idle_threshold2))) { swapout(p); didswap++; /* * swapout() unlocks a proc lock. This is * ugly, but avoids superfluous lock. */ mtx_unlock_spin(&sched_lock); vm_map_unlock(&vm->vm_map); vmspace_free(vm); sx_sunlock(&allproc_lock); goto retry; } } nextproc: mtx_unlock_spin(&sched_lock); nextproc2: PROC_UNLOCK(p); vm_map_unlock(&vm->vm_map); nextproc1: vmspace_free(vm); continue; } sx_sunlock(&allproc_lock); /* * If we swapped something out, and another process needed memory, * then wakeup the sched process. */ if (didswap) wakeup(&proc0); } static void swapout(p) struct proc *p; { struct thread *td; PROC_LOCK_ASSERT(p, MA_OWNED); mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED); #if defined(SWAP_DEBUG) printf("swapping out %d\n", p->p_pid); #endif /* * The states of this process and its threads may have changed * by now. Assuming that there is only one pageout daemon thread, * this process should still be in memory. */ KASSERT((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) == PS_INMEM, ("swapout: lost a swapout race?")); #if defined(INVARIANTS) /* * Make sure that all threads are safe to be swapped out. * * Alternatively, we could swap out only safe threads. */ FOREACH_THREAD_IN_PROC(p, td) { KASSERT(thread_safetoswapout(td), ("swapout: there is a thread not safe for swapout")); } #endif /* INVARIANTS */ ++p->p_stats->p_ru.ru_nswap; /* * remember the process resident count */ p->p_vmspace->vm_swrss = vmspace_resident_count(p->p_vmspace); PROC_UNLOCK(p); FOREACH_THREAD_IN_PROC (p, td) if (td->td_state == TDS_RUNQ) { /* XXXKSE */ remrunqueue(td); /* XXXKSE */ td->td_state = TDS_SWAPPED; } p->p_sflag &= ~PS_INMEM; p->p_sflag |= PS_SWAPPING; mtx_unlock_spin(&sched_lock); vm_proc_swapout(p); FOREACH_THREAD_IN_PROC(p, td) pmap_swapout_thread(td); mtx_lock_spin(&sched_lock); p->p_sflag &= ~PS_SWAPPING; p->p_swtime = 0; } #endif /* !NO_SWAPPING */