e725dd5c1e
originally inspired by the Solaris vmem detailed in the proceedings of usenix 2001. The NetBSD version was heavily refactored for bugs and simplicity. - Use this resource allocator to allocate the buffer and transient maps. Buffer cache defrags are reduced by 25% when used by filesystems with mixed block sizes. Ultimately this may permit dynamic buffer cache sizing on low KVA machines. Discussed with: alc, kib, attilio Tested by: pho Sponsored by: EMC / Isilon Storage Division
2404 lines
63 KiB
C
2404 lines
63 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* The Mach Operating System project at Carnegie-Mellon University.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94
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*
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*
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* Copyright (c) 1987, 1990 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Authors: Avadis Tevanian, Jr., Michael Wayne Young
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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/*
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* Virtual memory object module.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_vm.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/mman.h>
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#include <sys/mount.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <sys/mutex.h>
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#include <sys/proc.h> /* for curproc, pageproc */
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#include <sys/socket.h>
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#include <sys/resourcevar.h>
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#include <sys/rwlock.h>
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#include <sys/vnode.h>
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#include <sys/vmmeter.h>
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#include <sys/sx.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_object.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pageout.h>
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#include <vm/vm_pager.h>
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#include <vm/swap_pager.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_radix.h>
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#include <vm/vm_reserv.h>
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#include <vm/uma.h>
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static int old_msync;
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SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0,
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"Use old (insecure) msync behavior");
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static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p,
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int pagerflags, int flags, boolean_t *clearobjflags,
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boolean_t *eio);
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static boolean_t vm_object_page_remove_write(vm_page_t p, int flags,
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boolean_t *clearobjflags);
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static void vm_object_qcollapse(vm_object_t object);
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static void vm_object_vndeallocate(vm_object_t object);
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/*
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* Virtual memory objects maintain the actual data
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* associated with allocated virtual memory. A given
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* page of memory exists within exactly one object.
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*
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* An object is only deallocated when all "references"
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* are given up. Only one "reference" to a given
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* region of an object should be writeable.
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*
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* Associated with each object is a list of all resident
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* memory pages belonging to that object; this list is
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* maintained by the "vm_page" module, and locked by the object's
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* lock.
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*
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* Each object also records a "pager" routine which is
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* used to retrieve (and store) pages to the proper backing
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* storage. In addition, objects may be backed by other
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* objects from which they were virtual-copied.
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*
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* The only items within the object structure which are
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* modified after time of creation are:
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* reference count locked by object's lock
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* pager routine locked by object's lock
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*
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*/
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struct object_q vm_object_list;
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struct mtx vm_object_list_mtx; /* lock for object list and count */
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struct vm_object kernel_object_store;
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struct vm_object kmem_object_store;
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static SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD, 0,
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"VM object stats");
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static long object_collapses;
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SYSCTL_LONG(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD,
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&object_collapses, 0, "VM object collapses");
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static long object_bypasses;
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SYSCTL_LONG(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD,
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&object_bypasses, 0, "VM object bypasses");
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static uma_zone_t obj_zone;
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static int vm_object_zinit(void *mem, int size, int flags);
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#ifdef INVARIANTS
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static void vm_object_zdtor(void *mem, int size, void *arg);
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static void
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vm_object_zdtor(void *mem, int size, void *arg)
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{
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vm_object_t object;
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object = (vm_object_t)mem;
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KASSERT(TAILQ_EMPTY(&object->memq),
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("object %p has resident pages in its memq", object));
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KASSERT(vm_radix_is_empty(&object->rtree),
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("object %p has resident pages in its trie", object));
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#if VM_NRESERVLEVEL > 0
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KASSERT(LIST_EMPTY(&object->rvq),
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("object %p has reservations",
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object));
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#endif
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KASSERT(vm_object_cache_is_empty(object),
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("object %p has cached pages",
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object));
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KASSERT(object->paging_in_progress == 0,
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("object %p paging_in_progress = %d",
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object, object->paging_in_progress));
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KASSERT(object->resident_page_count == 0,
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("object %p resident_page_count = %d",
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object, object->resident_page_count));
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KASSERT(object->shadow_count == 0,
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("object %p shadow_count = %d",
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object, object->shadow_count));
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}
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#endif
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static int
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vm_object_zinit(void *mem, int size, int flags)
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{
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vm_object_t object;
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object = (vm_object_t)mem;
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bzero(&object->lock, sizeof(object->lock));
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rw_init_flags(&object->lock, "vm object", RW_DUPOK);
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/* These are true for any object that has been freed */
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object->rtree.rt_root = 0;
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object->paging_in_progress = 0;
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object->resident_page_count = 0;
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object->shadow_count = 0;
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object->cache.rt_root = 0;
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return (0);
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}
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static void
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_vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object)
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{
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TAILQ_INIT(&object->memq);
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LIST_INIT(&object->shadow_head);
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object->type = type;
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switch (type) {
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case OBJT_DEAD:
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panic("_vm_object_allocate: can't create OBJT_DEAD");
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case OBJT_DEFAULT:
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case OBJT_SWAP:
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object->flags = OBJ_ONEMAPPING;
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break;
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case OBJT_DEVICE:
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case OBJT_SG:
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object->flags = OBJ_FICTITIOUS | OBJ_UNMANAGED;
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break;
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case OBJT_MGTDEVICE:
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object->flags = OBJ_FICTITIOUS;
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break;
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case OBJT_PHYS:
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object->flags = OBJ_UNMANAGED;
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break;
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case OBJT_VNODE:
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object->flags = 0;
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break;
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default:
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panic("_vm_object_allocate: type %d is undefined", type);
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}
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object->size = size;
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object->generation = 1;
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object->ref_count = 1;
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object->memattr = VM_MEMATTR_DEFAULT;
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object->cred = NULL;
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object->charge = 0;
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object->handle = NULL;
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object->backing_object = NULL;
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object->backing_object_offset = (vm_ooffset_t) 0;
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#if VM_NRESERVLEVEL > 0
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LIST_INIT(&object->rvq);
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#endif
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mtx_lock(&vm_object_list_mtx);
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TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
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mtx_unlock(&vm_object_list_mtx);
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}
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/*
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* vm_object_init:
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*
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* Initialize the VM objects module.
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*/
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void
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vm_object_init(void)
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{
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TAILQ_INIT(&vm_object_list);
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mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF);
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rw_init(&kernel_object->lock, "kernel vm object");
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_vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
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kernel_object);
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#if VM_NRESERVLEVEL > 0
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kernel_object->flags |= OBJ_COLORED;
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kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
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#endif
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rw_init(&kmem_object->lock, "kmem vm object");
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_vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
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kmem_object);
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#if VM_NRESERVLEVEL > 0
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kmem_object->flags |= OBJ_COLORED;
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kmem_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
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#endif
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/*
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* The lock portion of struct vm_object must be type stable due
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* to vm_pageout_fallback_object_lock locking a vm object
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* without holding any references to it.
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*/
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obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
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#ifdef INVARIANTS
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vm_object_zdtor,
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#else
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NULL,
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#endif
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vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE);
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vm_radix_init();
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}
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void
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vm_object_clear_flag(vm_object_t object, u_short bits)
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{
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VM_OBJECT_ASSERT_WLOCKED(object);
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object->flags &= ~bits;
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}
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|
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/*
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* Sets the default memory attribute for the specified object. Pages
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* that are allocated to this object are by default assigned this memory
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* attribute.
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*
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* Presently, this function must be called before any pages are allocated
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* to the object. In the future, this requirement may be relaxed for
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* "default" and "swap" objects.
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*/
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int
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vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr)
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{
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VM_OBJECT_ASSERT_WLOCKED(object);
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switch (object->type) {
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case OBJT_DEFAULT:
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case OBJT_DEVICE:
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case OBJT_MGTDEVICE:
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case OBJT_PHYS:
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case OBJT_SG:
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case OBJT_SWAP:
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case OBJT_VNODE:
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if (!TAILQ_EMPTY(&object->memq))
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return (KERN_FAILURE);
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break;
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case OBJT_DEAD:
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return (KERN_INVALID_ARGUMENT);
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default:
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panic("vm_object_set_memattr: object %p is of undefined type",
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object);
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}
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object->memattr = memattr;
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return (KERN_SUCCESS);
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}
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void
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vm_object_pip_add(vm_object_t object, short i)
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{
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VM_OBJECT_ASSERT_WLOCKED(object);
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object->paging_in_progress += i;
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}
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void
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vm_object_pip_subtract(vm_object_t object, short i)
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{
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VM_OBJECT_ASSERT_WLOCKED(object);
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object->paging_in_progress -= i;
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}
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void
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vm_object_pip_wakeup(vm_object_t object)
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{
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VM_OBJECT_ASSERT_WLOCKED(object);
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object->paging_in_progress--;
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if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
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vm_object_clear_flag(object, OBJ_PIPWNT);
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wakeup(object);
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}
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}
|
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|
|
void
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vm_object_pip_wakeupn(vm_object_t object, short i)
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{
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
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if (i)
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object->paging_in_progress -= i;
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if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
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vm_object_clear_flag(object, OBJ_PIPWNT);
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wakeup(object);
|
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}
|
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}
|
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|
|
void
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vm_object_pip_wait(vm_object_t object, char *waitid)
|
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{
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
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while (object->paging_in_progress) {
|
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object->flags |= OBJ_PIPWNT;
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VM_OBJECT_SLEEP(object, object, PVM, waitid, 0);
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}
|
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}
|
|
|
|
/*
|
|
* vm_object_allocate:
|
|
*
|
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* Returns a new object with the given size.
|
|
*/
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vm_object_t
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vm_object_allocate(objtype_t type, vm_pindex_t size)
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|
{
|
|
vm_object_t object;
|
|
|
|
object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK);
|
|
_vm_object_allocate(type, size, object);
|
|
return (object);
|
|
}
|
|
|
|
|
|
/*
|
|
* vm_object_reference:
|
|
*
|
|
* Gets another reference to the given object. Note: OBJ_DEAD
|
|
* objects can be referenced during final cleaning.
|
|
*/
|
|
void
|
|
vm_object_reference(vm_object_t object)
|
|
{
|
|
if (object == NULL)
|
|
return;
|
|
VM_OBJECT_WLOCK(object);
|
|
vm_object_reference_locked(object);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
}
|
|
|
|
/*
|
|
* vm_object_reference_locked:
|
|
*
|
|
* Gets another reference to the given object.
|
|
*
|
|
* The object must be locked.
|
|
*/
|
|
void
|
|
vm_object_reference_locked(vm_object_t object)
|
|
{
|
|
struct vnode *vp;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
object->ref_count++;
|
|
if (object->type == OBJT_VNODE) {
|
|
vp = object->handle;
|
|
vref(vp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Handle deallocating an object of type OBJT_VNODE.
|
|
*/
|
|
static void
|
|
vm_object_vndeallocate(vm_object_t object)
|
|
{
|
|
struct vnode *vp = (struct vnode *) object->handle;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
KASSERT(object->type == OBJT_VNODE,
|
|
("vm_object_vndeallocate: not a vnode object"));
|
|
KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
|
|
#ifdef INVARIANTS
|
|
if (object->ref_count == 0) {
|
|
vprint("vm_object_vndeallocate", vp);
|
|
panic("vm_object_vndeallocate: bad object reference count");
|
|
}
|
|
#endif
|
|
|
|
if (object->ref_count > 1) {
|
|
object->ref_count--;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
/* vrele may need the vnode lock. */
|
|
vrele(vp);
|
|
} else {
|
|
vhold(vp);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
|
|
vdrop(vp);
|
|
VM_OBJECT_WLOCK(object);
|
|
object->ref_count--;
|
|
if (object->type == OBJT_DEAD) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
VOP_UNLOCK(vp, 0);
|
|
} else {
|
|
if (object->ref_count == 0)
|
|
VOP_UNSET_TEXT(vp);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
vput(vp);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_object_deallocate:
|
|
*
|
|
* Release a reference to the specified object,
|
|
* gained either through a vm_object_allocate
|
|
* or a vm_object_reference call. When all references
|
|
* are gone, storage associated with this object
|
|
* may be relinquished.
|
|
*
|
|
* No object may be locked.
|
|
*/
|
|
void
|
|
vm_object_deallocate(vm_object_t object)
|
|
{
|
|
vm_object_t temp;
|
|
struct vnode *vp;
|
|
|
|
while (object != NULL) {
|
|
VM_OBJECT_WLOCK(object);
|
|
if (object->type == OBJT_VNODE) {
|
|
vm_object_vndeallocate(object);
|
|
return;
|
|
}
|
|
|
|
KASSERT(object->ref_count != 0,
|
|
("vm_object_deallocate: object deallocated too many times: %d", object->type));
|
|
|
|
/*
|
|
* If the reference count goes to 0 we start calling
|
|
* vm_object_terminate() on the object chain.
|
|
* A ref count of 1 may be a special case depending on the
|
|
* shadow count being 0 or 1.
|
|
*/
|
|
object->ref_count--;
|
|
if (object->ref_count > 1) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return;
|
|
} else if (object->ref_count == 1) {
|
|
if (object->type == OBJT_SWAP &&
|
|
(object->flags & OBJ_TMPFS) != 0) {
|
|
vp = object->un_pager.swp.swp_tmpfs;
|
|
vhold(vp);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
|
|
vdrop(vp);
|
|
VM_OBJECT_WLOCK(object);
|
|
if (object->type == OBJT_DEAD ||
|
|
object->ref_count != 1) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
VOP_UNLOCK(vp, 0);
|
|
return;
|
|
}
|
|
if ((object->flags & OBJ_TMPFS) != 0)
|
|
VOP_UNSET_TEXT(vp);
|
|
VOP_UNLOCK(vp, 0);
|
|
}
|
|
if (object->shadow_count == 0 &&
|
|
object->handle == NULL &&
|
|
(object->type == OBJT_DEFAULT ||
|
|
(object->type == OBJT_SWAP &&
|
|
(object->flags & OBJ_TMPFS) == 0))) {
|
|
vm_object_set_flag(object, OBJ_ONEMAPPING);
|
|
} else if ((object->shadow_count == 1) &&
|
|
(object->handle == NULL) &&
|
|
(object->type == OBJT_DEFAULT ||
|
|
object->type == OBJT_SWAP)) {
|
|
KASSERT((object->flags & OBJ_TMPFS) == 0,
|
|
("shadowed tmpfs v_object %p", object));
|
|
vm_object_t robject;
|
|
|
|
robject = LIST_FIRST(&object->shadow_head);
|
|
KASSERT(robject != NULL,
|
|
("vm_object_deallocate: ref_count: %d, shadow_count: %d",
|
|
object->ref_count,
|
|
object->shadow_count));
|
|
if (!VM_OBJECT_TRYWLOCK(robject)) {
|
|
/*
|
|
* Avoid a potential deadlock.
|
|
*/
|
|
object->ref_count++;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
/*
|
|
* More likely than not the thread
|
|
* holding robject's lock has lower
|
|
* priority than the current thread.
|
|
* Let the lower priority thread run.
|
|
*/
|
|
pause("vmo_de", 1);
|
|
continue;
|
|
}
|
|
/*
|
|
* Collapse object into its shadow unless its
|
|
* shadow is dead. In that case, object will
|
|
* be deallocated by the thread that is
|
|
* deallocating its shadow.
|
|
*/
|
|
if ((robject->flags & OBJ_DEAD) == 0 &&
|
|
(robject->handle == NULL) &&
|
|
(robject->type == OBJT_DEFAULT ||
|
|
robject->type == OBJT_SWAP)) {
|
|
|
|
robject->ref_count++;
|
|
retry:
|
|
if (robject->paging_in_progress) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
vm_object_pip_wait(robject,
|
|
"objde1");
|
|
temp = robject->backing_object;
|
|
if (object == temp) {
|
|
VM_OBJECT_WLOCK(object);
|
|
goto retry;
|
|
}
|
|
} else if (object->paging_in_progress) {
|
|
VM_OBJECT_WUNLOCK(robject);
|
|
object->flags |= OBJ_PIPWNT;
|
|
VM_OBJECT_SLEEP(object, object,
|
|
PDROP | PVM, "objde2", 0);
|
|
VM_OBJECT_WLOCK(robject);
|
|
temp = robject->backing_object;
|
|
if (object == temp) {
|
|
VM_OBJECT_WLOCK(object);
|
|
goto retry;
|
|
}
|
|
} else
|
|
VM_OBJECT_WUNLOCK(object);
|
|
|
|
if (robject->ref_count == 1) {
|
|
robject->ref_count--;
|
|
object = robject;
|
|
goto doterm;
|
|
}
|
|
object = robject;
|
|
vm_object_collapse(object);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
continue;
|
|
}
|
|
VM_OBJECT_WUNLOCK(robject);
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return;
|
|
}
|
|
doterm:
|
|
temp = object->backing_object;
|
|
if (temp != NULL) {
|
|
VM_OBJECT_WLOCK(temp);
|
|
LIST_REMOVE(object, shadow_list);
|
|
temp->shadow_count--;
|
|
VM_OBJECT_WUNLOCK(temp);
|
|
object->backing_object = NULL;
|
|
}
|
|
/*
|
|
* Don't double-terminate, we could be in a termination
|
|
* recursion due to the terminate having to sync data
|
|
* to disk.
|
|
*/
|
|
if ((object->flags & OBJ_DEAD) == 0)
|
|
vm_object_terminate(object);
|
|
else
|
|
VM_OBJECT_WUNLOCK(object);
|
|
object = temp;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_object_destroy removes the object from the global object list
|
|
* and frees the space for the object.
|
|
*/
|
|
void
|
|
vm_object_destroy(vm_object_t object)
|
|
{
|
|
|
|
/*
|
|
* Remove the object from the global object list.
|
|
*/
|
|
mtx_lock(&vm_object_list_mtx);
|
|
TAILQ_REMOVE(&vm_object_list, object, object_list);
|
|
mtx_unlock(&vm_object_list_mtx);
|
|
|
|
/*
|
|
* Release the allocation charge.
|
|
*/
|
|
if (object->cred != NULL) {
|
|
KASSERT(object->type == OBJT_DEFAULT ||
|
|
object->type == OBJT_SWAP,
|
|
("vm_object_terminate: non-swap obj %p has cred",
|
|
object));
|
|
swap_release_by_cred(object->charge, object->cred);
|
|
object->charge = 0;
|
|
crfree(object->cred);
|
|
object->cred = NULL;
|
|
}
|
|
|
|
/*
|
|
* Free the space for the object.
|
|
*/
|
|
uma_zfree(obj_zone, object);
|
|
}
|
|
|
|
/*
|
|
* vm_object_terminate actually destroys the specified object, freeing
|
|
* up all previously used resources.
|
|
*
|
|
* The object must be locked.
|
|
* This routine may block.
|
|
*/
|
|
void
|
|
vm_object_terminate(vm_object_t object)
|
|
{
|
|
vm_page_t p, p_next;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
|
|
/*
|
|
* Make sure no one uses us.
|
|
*/
|
|
vm_object_set_flag(object, OBJ_DEAD);
|
|
|
|
/*
|
|
* wait for the pageout daemon to be done with the object
|
|
*/
|
|
vm_object_pip_wait(object, "objtrm");
|
|
|
|
KASSERT(!object->paging_in_progress,
|
|
("vm_object_terminate: pageout in progress"));
|
|
|
|
/*
|
|
* Clean and free the pages, as appropriate. All references to the
|
|
* object are gone, so we don't need to lock it.
|
|
*/
|
|
if (object->type == OBJT_VNODE) {
|
|
struct vnode *vp = (struct vnode *)object->handle;
|
|
|
|
/*
|
|
* Clean pages and flush buffers.
|
|
*/
|
|
vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
|
|
vinvalbuf(vp, V_SAVE, 0, 0);
|
|
|
|
VM_OBJECT_WLOCK(object);
|
|
}
|
|
|
|
KASSERT(object->ref_count == 0,
|
|
("vm_object_terminate: object with references, ref_count=%d",
|
|
object->ref_count));
|
|
|
|
/*
|
|
* Free any remaining pageable pages. This also removes them from the
|
|
* paging queues. However, don't free wired pages, just remove them
|
|
* from the object. Rather than incrementally removing each page from
|
|
* the object, the page and object are reset to any empty state.
|
|
*/
|
|
TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) {
|
|
KASSERT(!p->busy && (p->oflags & VPO_BUSY) == 0,
|
|
("vm_object_terminate: freeing busy page %p", p));
|
|
vm_page_lock(p);
|
|
/*
|
|
* Optimize the page's removal from the object by resetting
|
|
* its "object" field. Specifically, if the page is not
|
|
* wired, then the effect of this assignment is that
|
|
* vm_page_free()'s call to vm_page_remove() will return
|
|
* immediately without modifying the page or the object.
|
|
*/
|
|
p->object = NULL;
|
|
if (p->wire_count == 0) {
|
|
vm_page_free(p);
|
|
PCPU_INC(cnt.v_pfree);
|
|
}
|
|
vm_page_unlock(p);
|
|
}
|
|
/*
|
|
* If the object contained any pages, then reset it to an empty state.
|
|
* None of the object's fields, including "resident_page_count", were
|
|
* modified by the preceding loop.
|
|
*/
|
|
if (object->resident_page_count != 0) {
|
|
vm_radix_reclaim_allnodes(&object->rtree);
|
|
TAILQ_INIT(&object->memq);
|
|
object->resident_page_count = 0;
|
|
if (object->type == OBJT_VNODE)
|
|
vdrop(object->handle);
|
|
}
|
|
|
|
#if VM_NRESERVLEVEL > 0
|
|
if (__predict_false(!LIST_EMPTY(&object->rvq)))
|
|
vm_reserv_break_all(object);
|
|
#endif
|
|
if (__predict_false(!vm_object_cache_is_empty(object)))
|
|
vm_page_cache_free(object, 0, 0);
|
|
|
|
/*
|
|
* Let the pager know object is dead.
|
|
*/
|
|
vm_pager_deallocate(object);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
|
|
vm_object_destroy(object);
|
|
}
|
|
|
|
/*
|
|
* Make the page read-only so that we can clear the object flags. However, if
|
|
* this is a nosync mmap then the object is likely to stay dirty so do not
|
|
* mess with the page and do not clear the object flags. Returns TRUE if the
|
|
* page should be flushed, and FALSE otherwise.
|
|
*/
|
|
static boolean_t
|
|
vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *clearobjflags)
|
|
{
|
|
|
|
/*
|
|
* If we have been asked to skip nosync pages and this is a
|
|
* nosync page, skip it. Note that the object flags were not
|
|
* cleared in this case so we do not have to set them.
|
|
*/
|
|
if ((flags & OBJPC_NOSYNC) != 0 && (p->oflags & VPO_NOSYNC) != 0) {
|
|
*clearobjflags = FALSE;
|
|
return (FALSE);
|
|
} else {
|
|
pmap_remove_write(p);
|
|
return (p->dirty != 0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_object_page_clean
|
|
*
|
|
* Clean all dirty pages in the specified range of object. Leaves page
|
|
* on whatever queue it is currently on. If NOSYNC is set then do not
|
|
* write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC),
|
|
* leaving the object dirty.
|
|
*
|
|
* When stuffing pages asynchronously, allow clustering. XXX we need a
|
|
* synchronous clustering mode implementation.
|
|
*
|
|
* Odd semantics: if start == end, we clean everything.
|
|
*
|
|
* The object must be locked.
|
|
*
|
|
* Returns FALSE if some page from the range was not written, as
|
|
* reported by the pager, and TRUE otherwise.
|
|
*/
|
|
boolean_t
|
|
vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end,
|
|
int flags)
|
|
{
|
|
vm_page_t np, p;
|
|
vm_pindex_t pi, tend, tstart;
|
|
int curgeneration, n, pagerflags;
|
|
boolean_t clearobjflags, eio, res;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
|
|
/*
|
|
* The OBJ_MIGHTBEDIRTY flag is only set for OBJT_VNODE
|
|
* objects. The check below prevents the function from
|
|
* operating on non-vnode objects.
|
|
*/
|
|
if ((object->flags & OBJ_MIGHTBEDIRTY) == 0 ||
|
|
object->resident_page_count == 0)
|
|
return (TRUE);
|
|
|
|
pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ?
|
|
VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
|
|
pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0;
|
|
|
|
tstart = OFF_TO_IDX(start);
|
|
tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK);
|
|
clearobjflags = tstart == 0 && tend >= object->size;
|
|
res = TRUE;
|
|
|
|
rescan:
|
|
curgeneration = object->generation;
|
|
|
|
for (p = vm_page_find_least(object, tstart); p != NULL; p = np) {
|
|
pi = p->pindex;
|
|
if (pi >= tend)
|
|
break;
|
|
np = TAILQ_NEXT(p, listq);
|
|
if (p->valid == 0)
|
|
continue;
|
|
if (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) {
|
|
if (object->generation != curgeneration) {
|
|
if ((flags & OBJPC_SYNC) != 0)
|
|
goto rescan;
|
|
else
|
|
clearobjflags = FALSE;
|
|
}
|
|
np = vm_page_find_least(object, pi);
|
|
continue;
|
|
}
|
|
if (!vm_object_page_remove_write(p, flags, &clearobjflags))
|
|
continue;
|
|
|
|
n = vm_object_page_collect_flush(object, p, pagerflags,
|
|
flags, &clearobjflags, &eio);
|
|
if (eio) {
|
|
res = FALSE;
|
|
clearobjflags = FALSE;
|
|
}
|
|
if (object->generation != curgeneration) {
|
|
if ((flags & OBJPC_SYNC) != 0)
|
|
goto rescan;
|
|
else
|
|
clearobjflags = FALSE;
|
|
}
|
|
|
|
/*
|
|
* If the VOP_PUTPAGES() did a truncated write, so
|
|
* that even the first page of the run is not fully
|
|
* written, vm_pageout_flush() returns 0 as the run
|
|
* length. Since the condition that caused truncated
|
|
* write may be permanent, e.g. exhausted free space,
|
|
* accepting n == 0 would cause an infinite loop.
|
|
*
|
|
* Forwarding the iterator leaves the unwritten page
|
|
* behind, but there is not much we can do there if
|
|
* filesystem refuses to write it.
|
|
*/
|
|
if (n == 0) {
|
|
n = 1;
|
|
clearobjflags = FALSE;
|
|
}
|
|
np = vm_page_find_least(object, pi + n);
|
|
}
|
|
#if 0
|
|
VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0);
|
|
#endif
|
|
|
|
if (clearobjflags)
|
|
vm_object_clear_flag(object, OBJ_MIGHTBEDIRTY);
|
|
return (res);
|
|
}
|
|
|
|
static int
|
|
vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags,
|
|
int flags, boolean_t *clearobjflags, boolean_t *eio)
|
|
{
|
|
vm_page_t ma[vm_pageout_page_count], p_first, tp;
|
|
int count, i, mreq, runlen;
|
|
|
|
vm_page_lock_assert(p, MA_NOTOWNED);
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
|
|
count = 1;
|
|
mreq = 0;
|
|
|
|
for (tp = p; count < vm_pageout_page_count; count++) {
|
|
tp = vm_page_next(tp);
|
|
if (tp == NULL || tp->busy != 0 || (tp->oflags & VPO_BUSY) != 0)
|
|
break;
|
|
if (!vm_object_page_remove_write(tp, flags, clearobjflags))
|
|
break;
|
|
}
|
|
|
|
for (p_first = p; count < vm_pageout_page_count; count++) {
|
|
tp = vm_page_prev(p_first);
|
|
if (tp == NULL || tp->busy != 0 || (tp->oflags & VPO_BUSY) != 0)
|
|
break;
|
|
if (!vm_object_page_remove_write(tp, flags, clearobjflags))
|
|
break;
|
|
p_first = tp;
|
|
mreq++;
|
|
}
|
|
|
|
for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++)
|
|
ma[i] = tp;
|
|
|
|
vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio);
|
|
return (runlen);
|
|
}
|
|
|
|
/*
|
|
* Note that there is absolutely no sense in writing out
|
|
* anonymous objects, so we track down the vnode object
|
|
* to write out.
|
|
* We invalidate (remove) all pages from the address space
|
|
* for semantic correctness.
|
|
*
|
|
* If the backing object is a device object with unmanaged pages, then any
|
|
* mappings to the specified range of pages must be removed before this
|
|
* function is called.
|
|
*
|
|
* Note: certain anonymous maps, such as MAP_NOSYNC maps,
|
|
* may start out with a NULL object.
|
|
*/
|
|
boolean_t
|
|
vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
|
|
boolean_t syncio, boolean_t invalidate)
|
|
{
|
|
vm_object_t backing_object;
|
|
struct vnode *vp;
|
|
struct mount *mp;
|
|
int error, flags, fsync_after;
|
|
boolean_t res;
|
|
|
|
if (object == NULL)
|
|
return (TRUE);
|
|
res = TRUE;
|
|
error = 0;
|
|
VM_OBJECT_WLOCK(object);
|
|
while ((backing_object = object->backing_object) != NULL) {
|
|
VM_OBJECT_WLOCK(backing_object);
|
|
offset += object->backing_object_offset;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
object = backing_object;
|
|
if (object->size < OFF_TO_IDX(offset + size))
|
|
size = IDX_TO_OFF(object->size) - offset;
|
|
}
|
|
/*
|
|
* Flush pages if writing is allowed, invalidate them
|
|
* if invalidation requested. Pages undergoing I/O
|
|
* will be ignored by vm_object_page_remove().
|
|
*
|
|
* We cannot lock the vnode and then wait for paging
|
|
* to complete without deadlocking against vm_fault.
|
|
* Instead we simply call vm_object_page_remove() and
|
|
* allow it to block internally on a page-by-page
|
|
* basis when it encounters pages undergoing async
|
|
* I/O.
|
|
*/
|
|
if (object->type == OBJT_VNODE &&
|
|
(object->flags & OBJ_MIGHTBEDIRTY) != 0) {
|
|
vp = object->handle;
|
|
VM_OBJECT_WUNLOCK(object);
|
|
(void) vn_start_write(vp, &mp, V_WAIT);
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
|
|
if (syncio && !invalidate && offset == 0 &&
|
|
OFF_TO_IDX(size) == object->size) {
|
|
/*
|
|
* If syncing the whole mapping of the file,
|
|
* it is faster to schedule all the writes in
|
|
* async mode, also allowing the clustering,
|
|
* and then wait for i/o to complete.
|
|
*/
|
|
flags = 0;
|
|
fsync_after = TRUE;
|
|
} else {
|
|
flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
|
|
flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0;
|
|
fsync_after = FALSE;
|
|
}
|
|
VM_OBJECT_WLOCK(object);
|
|
res = vm_object_page_clean(object, offset, offset + size,
|
|
flags);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
if (fsync_after)
|
|
error = VOP_FSYNC(vp, MNT_WAIT, curthread);
|
|
VOP_UNLOCK(vp, 0);
|
|
vn_finished_write(mp);
|
|
if (error != 0)
|
|
res = FALSE;
|
|
VM_OBJECT_WLOCK(object);
|
|
}
|
|
if ((object->type == OBJT_VNODE ||
|
|
object->type == OBJT_DEVICE) && invalidate) {
|
|
if (object->type == OBJT_DEVICE)
|
|
/*
|
|
* The option OBJPR_NOTMAPPED must be passed here
|
|
* because vm_object_page_remove() cannot remove
|
|
* unmanaged mappings.
|
|
*/
|
|
flags = OBJPR_NOTMAPPED;
|
|
else if (old_msync)
|
|
flags = 0;
|
|
else
|
|
flags = OBJPR_CLEANONLY;
|
|
vm_object_page_remove(object, OFF_TO_IDX(offset),
|
|
OFF_TO_IDX(offset + size + PAGE_MASK), flags);
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return (res);
|
|
}
|
|
|
|
/*
|
|
* vm_object_madvise:
|
|
*
|
|
* Implements the madvise function at the object/page level.
|
|
*
|
|
* MADV_WILLNEED (any object)
|
|
*
|
|
* Activate the specified pages if they are resident.
|
|
*
|
|
* MADV_DONTNEED (any object)
|
|
*
|
|
* Deactivate the specified pages if they are resident.
|
|
*
|
|
* MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
|
|
* OBJ_ONEMAPPING only)
|
|
*
|
|
* Deactivate and clean the specified pages if they are
|
|
* resident. This permits the process to reuse the pages
|
|
* without faulting or the kernel to reclaim the pages
|
|
* without I/O.
|
|
*/
|
|
void
|
|
vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end,
|
|
int advise)
|
|
{
|
|
vm_pindex_t tpindex;
|
|
vm_object_t backing_object, tobject;
|
|
vm_page_t m;
|
|
|
|
if (object == NULL)
|
|
return;
|
|
VM_OBJECT_WLOCK(object);
|
|
/*
|
|
* Locate and adjust resident pages
|
|
*/
|
|
for (; pindex < end; pindex += 1) {
|
|
relookup:
|
|
tobject = object;
|
|
tpindex = pindex;
|
|
shadowlookup:
|
|
/*
|
|
* MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
|
|
* and those pages must be OBJ_ONEMAPPING.
|
|
*/
|
|
if (advise == MADV_FREE) {
|
|
if ((tobject->type != OBJT_DEFAULT &&
|
|
tobject->type != OBJT_SWAP) ||
|
|
(tobject->flags & OBJ_ONEMAPPING) == 0) {
|
|
goto unlock_tobject;
|
|
}
|
|
} else if ((tobject->flags & OBJ_UNMANAGED) != 0)
|
|
goto unlock_tobject;
|
|
m = vm_page_lookup(tobject, tpindex);
|
|
if (m == NULL && advise == MADV_WILLNEED) {
|
|
/*
|
|
* If the page is cached, reactivate it.
|
|
*/
|
|
m = vm_page_alloc(tobject, tpindex, VM_ALLOC_IFCACHED |
|
|
VM_ALLOC_NOBUSY);
|
|
}
|
|
if (m == NULL) {
|
|
/*
|
|
* There may be swap even if there is no backing page
|
|
*/
|
|
if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
|
|
swap_pager_freespace(tobject, tpindex, 1);
|
|
/*
|
|
* next object
|
|
*/
|
|
backing_object = tobject->backing_object;
|
|
if (backing_object == NULL)
|
|
goto unlock_tobject;
|
|
VM_OBJECT_WLOCK(backing_object);
|
|
tpindex += OFF_TO_IDX(tobject->backing_object_offset);
|
|
if (tobject != object)
|
|
VM_OBJECT_WUNLOCK(tobject);
|
|
tobject = backing_object;
|
|
goto shadowlookup;
|
|
} else if (m->valid != VM_PAGE_BITS_ALL)
|
|
goto unlock_tobject;
|
|
/*
|
|
* If the page is not in a normal state, skip it.
|
|
*/
|
|
vm_page_lock(m);
|
|
if (m->hold_count != 0 || m->wire_count != 0) {
|
|
vm_page_unlock(m);
|
|
goto unlock_tobject;
|
|
}
|
|
KASSERT((m->flags & PG_FICTITIOUS) == 0,
|
|
("vm_object_madvise: page %p is fictitious", m));
|
|
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
|
|
("vm_object_madvise: page %p is not managed", m));
|
|
if ((m->oflags & VPO_BUSY) || m->busy) {
|
|
if (advise == MADV_WILLNEED) {
|
|
/*
|
|
* Reference the page before unlocking and
|
|
* sleeping so that the page daemon is less
|
|
* likely to reclaim it.
|
|
*/
|
|
vm_page_aflag_set(m, PGA_REFERENCED);
|
|
}
|
|
vm_page_unlock(m);
|
|
if (object != tobject)
|
|
VM_OBJECT_WUNLOCK(object);
|
|
m->oflags |= VPO_WANTED;
|
|
VM_OBJECT_SLEEP(tobject, m, PDROP | PVM, "madvpo", 0);
|
|
VM_OBJECT_WLOCK(object);
|
|
goto relookup;
|
|
}
|
|
if (advise == MADV_WILLNEED) {
|
|
vm_page_activate(m);
|
|
} else {
|
|
vm_page_advise(m, advise);
|
|
}
|
|
vm_page_unlock(m);
|
|
if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
|
|
swap_pager_freespace(tobject, tpindex, 1);
|
|
unlock_tobject:
|
|
if (tobject != object)
|
|
VM_OBJECT_WUNLOCK(tobject);
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
}
|
|
|
|
/*
|
|
* vm_object_shadow:
|
|
*
|
|
* Create a new object which is backed by the
|
|
* specified existing object range. The source
|
|
* object reference is deallocated.
|
|
*
|
|
* The new object and offset into that object
|
|
* are returned in the source parameters.
|
|
*/
|
|
void
|
|
vm_object_shadow(
|
|
vm_object_t *object, /* IN/OUT */
|
|
vm_ooffset_t *offset, /* IN/OUT */
|
|
vm_size_t length)
|
|
{
|
|
vm_object_t source;
|
|
vm_object_t result;
|
|
|
|
source = *object;
|
|
|
|
/*
|
|
* Don't create the new object if the old object isn't shared.
|
|
*/
|
|
if (source != NULL) {
|
|
VM_OBJECT_WLOCK(source);
|
|
if (source->ref_count == 1 &&
|
|
source->handle == NULL &&
|
|
(source->type == OBJT_DEFAULT ||
|
|
source->type == OBJT_SWAP)) {
|
|
VM_OBJECT_WUNLOCK(source);
|
|
return;
|
|
}
|
|
VM_OBJECT_WUNLOCK(source);
|
|
}
|
|
|
|
/*
|
|
* Allocate a new object with the given length.
|
|
*/
|
|
result = vm_object_allocate(OBJT_DEFAULT, atop(length));
|
|
|
|
/*
|
|
* The new object shadows the source object, adding a reference to it.
|
|
* Our caller changes his reference to point to the new object,
|
|
* removing a reference to the source object. Net result: no change
|
|
* of reference count.
|
|
*
|
|
* Try to optimize the result object's page color when shadowing
|
|
* in order to maintain page coloring consistency in the combined
|
|
* shadowed object.
|
|
*/
|
|
result->backing_object = source;
|
|
/*
|
|
* Store the offset into the source object, and fix up the offset into
|
|
* the new object.
|
|
*/
|
|
result->backing_object_offset = *offset;
|
|
if (source != NULL) {
|
|
VM_OBJECT_WLOCK(source);
|
|
LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
|
|
source->shadow_count++;
|
|
#if VM_NRESERVLEVEL > 0
|
|
result->flags |= source->flags & OBJ_COLORED;
|
|
result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) &
|
|
((1 << (VM_NFREEORDER - 1)) - 1);
|
|
#endif
|
|
VM_OBJECT_WUNLOCK(source);
|
|
}
|
|
|
|
|
|
/*
|
|
* Return the new things
|
|
*/
|
|
*offset = 0;
|
|
*object = result;
|
|
}
|
|
|
|
/*
|
|
* vm_object_split:
|
|
*
|
|
* Split the pages in a map entry into a new object. This affords
|
|
* easier removal of unused pages, and keeps object inheritance from
|
|
* being a negative impact on memory usage.
|
|
*/
|
|
void
|
|
vm_object_split(vm_map_entry_t entry)
|
|
{
|
|
vm_page_t m, m_next;
|
|
vm_object_t orig_object, new_object, source;
|
|
vm_pindex_t idx, offidxstart;
|
|
vm_size_t size;
|
|
|
|
orig_object = entry->object.vm_object;
|
|
if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
|
|
return;
|
|
if (orig_object->ref_count <= 1)
|
|
return;
|
|
VM_OBJECT_WUNLOCK(orig_object);
|
|
|
|
offidxstart = OFF_TO_IDX(entry->offset);
|
|
size = atop(entry->end - entry->start);
|
|
|
|
/*
|
|
* If swap_pager_copy() is later called, it will convert new_object
|
|
* into a swap object.
|
|
*/
|
|
new_object = vm_object_allocate(OBJT_DEFAULT, size);
|
|
|
|
/*
|
|
* At this point, the new object is still private, so the order in
|
|
* which the original and new objects are locked does not matter.
|
|
*/
|
|
VM_OBJECT_WLOCK(new_object);
|
|
VM_OBJECT_WLOCK(orig_object);
|
|
source = orig_object->backing_object;
|
|
if (source != NULL) {
|
|
VM_OBJECT_WLOCK(source);
|
|
if ((source->flags & OBJ_DEAD) != 0) {
|
|
VM_OBJECT_WUNLOCK(source);
|
|
VM_OBJECT_WUNLOCK(orig_object);
|
|
VM_OBJECT_WUNLOCK(new_object);
|
|
vm_object_deallocate(new_object);
|
|
VM_OBJECT_WLOCK(orig_object);
|
|
return;
|
|
}
|
|
LIST_INSERT_HEAD(&source->shadow_head,
|
|
new_object, shadow_list);
|
|
source->shadow_count++;
|
|
vm_object_reference_locked(source); /* for new_object */
|
|
vm_object_clear_flag(source, OBJ_ONEMAPPING);
|
|
VM_OBJECT_WUNLOCK(source);
|
|
new_object->backing_object_offset =
|
|
orig_object->backing_object_offset + entry->offset;
|
|
new_object->backing_object = source;
|
|
}
|
|
if (orig_object->cred != NULL) {
|
|
new_object->cred = orig_object->cred;
|
|
crhold(orig_object->cred);
|
|
new_object->charge = ptoa(size);
|
|
KASSERT(orig_object->charge >= ptoa(size),
|
|
("orig_object->charge < 0"));
|
|
orig_object->charge -= ptoa(size);
|
|
}
|
|
retry:
|
|
m = vm_page_find_least(orig_object, offidxstart);
|
|
for (; m != NULL && (idx = m->pindex - offidxstart) < size;
|
|
m = m_next) {
|
|
m_next = TAILQ_NEXT(m, listq);
|
|
|
|
/*
|
|
* We must wait for pending I/O to complete before we can
|
|
* rename the page.
|
|
*
|
|
* We do not have to VM_PROT_NONE the page as mappings should
|
|
* not be changed by this operation.
|
|
*/
|
|
if ((m->oflags & VPO_BUSY) || m->busy) {
|
|
VM_OBJECT_WUNLOCK(new_object);
|
|
m->oflags |= VPO_WANTED;
|
|
VM_OBJECT_SLEEP(orig_object, m, PVM, "spltwt", 0);
|
|
VM_OBJECT_WLOCK(new_object);
|
|
goto retry;
|
|
}
|
|
#if VM_NRESERVLEVEL > 0
|
|
/*
|
|
* If some of the reservation's allocated pages remain with
|
|
* the original object, then transferring the reservation to
|
|
* the new object is neither particularly beneficial nor
|
|
* particularly harmful as compared to leaving the reservation
|
|
* with the original object. If, however, all of the
|
|
* reservation's allocated pages are transferred to the new
|
|
* object, then transferring the reservation is typically
|
|
* beneficial. Determining which of these two cases applies
|
|
* would be more costly than unconditionally renaming the
|
|
* reservation.
|
|
*/
|
|
vm_reserv_rename(m, new_object, orig_object, offidxstart);
|
|
#endif
|
|
vm_page_lock(m);
|
|
vm_page_rename(m, new_object, idx);
|
|
vm_page_unlock(m);
|
|
/* page automatically made dirty by rename and cache handled */
|
|
if (orig_object->type == OBJT_SWAP)
|
|
vm_page_busy(m);
|
|
}
|
|
if (orig_object->type == OBJT_SWAP) {
|
|
/*
|
|
* swap_pager_copy() can sleep, in which case the orig_object's
|
|
* and new_object's locks are released and reacquired.
|
|
*/
|
|
swap_pager_copy(orig_object, new_object, offidxstart, 0);
|
|
TAILQ_FOREACH(m, &new_object->memq, listq)
|
|
vm_page_wakeup(m);
|
|
|
|
/*
|
|
* Transfer any cached pages from orig_object to new_object.
|
|
* If swap_pager_copy() found swapped out pages within the
|
|
* specified range of orig_object, then it changed
|
|
* new_object's type to OBJT_SWAP when it transferred those
|
|
* pages to new_object. Otherwise, new_object's type
|
|
* should still be OBJT_DEFAULT and orig_object should not
|
|
* contain any cached pages within the specified range.
|
|
*/
|
|
if (__predict_false(!vm_object_cache_is_empty(orig_object)))
|
|
vm_page_cache_transfer(orig_object, offidxstart,
|
|
new_object);
|
|
}
|
|
VM_OBJECT_WUNLOCK(orig_object);
|
|
VM_OBJECT_WUNLOCK(new_object);
|
|
entry->object.vm_object = new_object;
|
|
entry->offset = 0LL;
|
|
vm_object_deallocate(orig_object);
|
|
VM_OBJECT_WLOCK(new_object);
|
|
}
|
|
|
|
#define OBSC_TEST_ALL_SHADOWED 0x0001
|
|
#define OBSC_COLLAPSE_NOWAIT 0x0002
|
|
#define OBSC_COLLAPSE_WAIT 0x0004
|
|
|
|
static int
|
|
vm_object_backing_scan(vm_object_t object, int op)
|
|
{
|
|
int r = 1;
|
|
vm_page_t p;
|
|
vm_object_t backing_object;
|
|
vm_pindex_t backing_offset_index;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
VM_OBJECT_ASSERT_WLOCKED(object->backing_object);
|
|
|
|
backing_object = object->backing_object;
|
|
backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
|
|
|
|
/*
|
|
* Initial conditions
|
|
*/
|
|
if (op & OBSC_TEST_ALL_SHADOWED) {
|
|
/*
|
|
* We do not want to have to test for the existence of cache
|
|
* or swap pages in the backing object. XXX but with the
|
|
* new swapper this would be pretty easy to do.
|
|
*
|
|
* XXX what about anonymous MAP_SHARED memory that hasn't
|
|
* been ZFOD faulted yet? If we do not test for this, the
|
|
* shadow test may succeed! XXX
|
|
*/
|
|
if (backing_object->type != OBJT_DEFAULT) {
|
|
return (0);
|
|
}
|
|
}
|
|
if (op & OBSC_COLLAPSE_WAIT) {
|
|
vm_object_set_flag(backing_object, OBJ_DEAD);
|
|
}
|
|
|
|
/*
|
|
* Our scan
|
|
*/
|
|
p = TAILQ_FIRST(&backing_object->memq);
|
|
while (p) {
|
|
vm_page_t next = TAILQ_NEXT(p, listq);
|
|
vm_pindex_t new_pindex = p->pindex - backing_offset_index;
|
|
|
|
if (op & OBSC_TEST_ALL_SHADOWED) {
|
|
vm_page_t pp;
|
|
|
|
/*
|
|
* Ignore pages outside the parent object's range
|
|
* and outside the parent object's mapping of the
|
|
* backing object.
|
|
*
|
|
* note that we do not busy the backing object's
|
|
* page.
|
|
*/
|
|
if (
|
|
p->pindex < backing_offset_index ||
|
|
new_pindex >= object->size
|
|
) {
|
|
p = next;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* See if the parent has the page or if the parent's
|
|
* object pager has the page. If the parent has the
|
|
* page but the page is not valid, the parent's
|
|
* object pager must have the page.
|
|
*
|
|
* If this fails, the parent does not completely shadow
|
|
* the object and we might as well give up now.
|
|
*/
|
|
|
|
pp = vm_page_lookup(object, new_pindex);
|
|
if (
|
|
(pp == NULL || pp->valid == 0) &&
|
|
!vm_pager_has_page(object, new_pindex, NULL, NULL)
|
|
) {
|
|
r = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check for busy page
|
|
*/
|
|
if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
|
|
vm_page_t pp;
|
|
|
|
if (op & OBSC_COLLAPSE_NOWAIT) {
|
|
if ((p->oflags & VPO_BUSY) ||
|
|
!p->valid ||
|
|
p->busy) {
|
|
p = next;
|
|
continue;
|
|
}
|
|
} else if (op & OBSC_COLLAPSE_WAIT) {
|
|
if ((p->oflags & VPO_BUSY) || p->busy) {
|
|
VM_OBJECT_WUNLOCK(object);
|
|
p->oflags |= VPO_WANTED;
|
|
VM_OBJECT_SLEEP(backing_object, p,
|
|
PDROP | PVM, "vmocol", 0);
|
|
VM_OBJECT_WLOCK(object);
|
|
VM_OBJECT_WLOCK(backing_object);
|
|
/*
|
|
* If we slept, anything could have
|
|
* happened. Since the object is
|
|
* marked dead, the backing offset
|
|
* should not have changed so we
|
|
* just restart our scan.
|
|
*/
|
|
p = TAILQ_FIRST(&backing_object->memq);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
KASSERT(
|
|
p->object == backing_object,
|
|
("vm_object_backing_scan: object mismatch")
|
|
);
|
|
|
|
/*
|
|
* Destroy any associated swap
|
|
*/
|
|
if (backing_object->type == OBJT_SWAP) {
|
|
swap_pager_freespace(
|
|
backing_object,
|
|
p->pindex,
|
|
1
|
|
);
|
|
}
|
|
|
|
if (
|
|
p->pindex < backing_offset_index ||
|
|
new_pindex >= object->size
|
|
) {
|
|
/*
|
|
* Page is out of the parent object's range, we
|
|
* can simply destroy it.
|
|
*/
|
|
vm_page_lock(p);
|
|
KASSERT(!pmap_page_is_mapped(p),
|
|
("freeing mapped page %p", p));
|
|
if (p->wire_count == 0)
|
|
vm_page_free(p);
|
|
else
|
|
vm_page_remove(p);
|
|
vm_page_unlock(p);
|
|
p = next;
|
|
continue;
|
|
}
|
|
|
|
pp = vm_page_lookup(object, new_pindex);
|
|
if (
|
|
(op & OBSC_COLLAPSE_NOWAIT) != 0 &&
|
|
(pp != NULL && pp->valid == 0)
|
|
) {
|
|
/*
|
|
* The page in the parent is not (yet) valid.
|
|
* We don't know anything about the state of
|
|
* the original page. It might be mapped,
|
|
* so we must avoid the next if here.
|
|
*
|
|
* This is due to a race in vm_fault() where
|
|
* we must unbusy the original (backing_obj)
|
|
* page before we can (re)lock the parent.
|
|
* Hence we can get here.
|
|
*/
|
|
p = next;
|
|
continue;
|
|
}
|
|
if (
|
|
pp != NULL ||
|
|
vm_pager_has_page(object, new_pindex, NULL, NULL)
|
|
) {
|
|
/*
|
|
* page already exists in parent OR swap exists
|
|
* for this location in the parent. Destroy
|
|
* the original page from the backing object.
|
|
*
|
|
* Leave the parent's page alone
|
|
*/
|
|
vm_page_lock(p);
|
|
KASSERT(!pmap_page_is_mapped(p),
|
|
("freeing mapped page %p", p));
|
|
if (p->wire_count == 0)
|
|
vm_page_free(p);
|
|
else
|
|
vm_page_remove(p);
|
|
vm_page_unlock(p);
|
|
p = next;
|
|
continue;
|
|
}
|
|
|
|
#if VM_NRESERVLEVEL > 0
|
|
/*
|
|
* Rename the reservation.
|
|
*/
|
|
vm_reserv_rename(p, object, backing_object,
|
|
backing_offset_index);
|
|
#endif
|
|
|
|
/*
|
|
* Page does not exist in parent, rename the
|
|
* page from the backing object to the main object.
|
|
*
|
|
* If the page was mapped to a process, it can remain
|
|
* mapped through the rename.
|
|
*/
|
|
vm_page_lock(p);
|
|
vm_page_rename(p, object, new_pindex);
|
|
vm_page_unlock(p);
|
|
/* page automatically made dirty by rename */
|
|
}
|
|
p = next;
|
|
}
|
|
return (r);
|
|
}
|
|
|
|
|
|
/*
|
|
* this version of collapse allows the operation to occur earlier and
|
|
* when paging_in_progress is true for an object... This is not a complete
|
|
* operation, but should plug 99.9% of the rest of the leaks.
|
|
*/
|
|
static void
|
|
vm_object_qcollapse(vm_object_t object)
|
|
{
|
|
vm_object_t backing_object = object->backing_object;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
VM_OBJECT_ASSERT_WLOCKED(backing_object);
|
|
|
|
if (backing_object->ref_count != 1)
|
|
return;
|
|
|
|
vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
|
|
}
|
|
|
|
/*
|
|
* vm_object_collapse:
|
|
*
|
|
* Collapse an object with the object backing it.
|
|
* Pages in the backing object are moved into the
|
|
* parent, and the backing object is deallocated.
|
|
*/
|
|
void
|
|
vm_object_collapse(vm_object_t object)
|
|
{
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
|
|
while (TRUE) {
|
|
vm_object_t backing_object;
|
|
|
|
/*
|
|
* Verify that the conditions are right for collapse:
|
|
*
|
|
* The object exists and the backing object exists.
|
|
*/
|
|
if ((backing_object = object->backing_object) == NULL)
|
|
break;
|
|
|
|
/*
|
|
* we check the backing object first, because it is most likely
|
|
* not collapsable.
|
|
*/
|
|
VM_OBJECT_WLOCK(backing_object);
|
|
if (backing_object->handle != NULL ||
|
|
(backing_object->type != OBJT_DEFAULT &&
|
|
backing_object->type != OBJT_SWAP) ||
|
|
(backing_object->flags & OBJ_DEAD) ||
|
|
object->handle != NULL ||
|
|
(object->type != OBJT_DEFAULT &&
|
|
object->type != OBJT_SWAP) ||
|
|
(object->flags & OBJ_DEAD)) {
|
|
VM_OBJECT_WUNLOCK(backing_object);
|
|
break;
|
|
}
|
|
|
|
if (
|
|
object->paging_in_progress != 0 ||
|
|
backing_object->paging_in_progress != 0
|
|
) {
|
|
vm_object_qcollapse(object);
|
|
VM_OBJECT_WUNLOCK(backing_object);
|
|
break;
|
|
}
|
|
/*
|
|
* We know that we can either collapse the backing object (if
|
|
* the parent is the only reference to it) or (perhaps) have
|
|
* the parent bypass the object if the parent happens to shadow
|
|
* all the resident pages in the entire backing object.
|
|
*
|
|
* This is ignoring pager-backed pages such as swap pages.
|
|
* vm_object_backing_scan fails the shadowing test in this
|
|
* case.
|
|
*/
|
|
if (backing_object->ref_count == 1) {
|
|
/*
|
|
* If there is exactly one reference to the backing
|
|
* object, we can collapse it into the parent.
|
|
*/
|
|
vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
|
|
|
|
#if VM_NRESERVLEVEL > 0
|
|
/*
|
|
* Break any reservations from backing_object.
|
|
*/
|
|
if (__predict_false(!LIST_EMPTY(&backing_object->rvq)))
|
|
vm_reserv_break_all(backing_object);
|
|
#endif
|
|
|
|
/*
|
|
* Move the pager from backing_object to object.
|
|
*/
|
|
if (backing_object->type == OBJT_SWAP) {
|
|
/*
|
|
* swap_pager_copy() can sleep, in which case
|
|
* the backing_object's and object's locks are
|
|
* released and reacquired.
|
|
* Since swap_pager_copy() is being asked to
|
|
* destroy the source, it will change the
|
|
* backing_object's type to OBJT_DEFAULT.
|
|
*/
|
|
swap_pager_copy(
|
|
backing_object,
|
|
object,
|
|
OFF_TO_IDX(object->backing_object_offset), TRUE);
|
|
|
|
/*
|
|
* Free any cached pages from backing_object.
|
|
*/
|
|
if (__predict_false(
|
|
!vm_object_cache_is_empty(backing_object)))
|
|
vm_page_cache_free(backing_object, 0, 0);
|
|
}
|
|
/*
|
|
* Object now shadows whatever backing_object did.
|
|
* Note that the reference to
|
|
* backing_object->backing_object moves from within
|
|
* backing_object to within object.
|
|
*/
|
|
LIST_REMOVE(object, shadow_list);
|
|
backing_object->shadow_count--;
|
|
if (backing_object->backing_object) {
|
|
VM_OBJECT_WLOCK(backing_object->backing_object);
|
|
LIST_REMOVE(backing_object, shadow_list);
|
|
LIST_INSERT_HEAD(
|
|
&backing_object->backing_object->shadow_head,
|
|
object, shadow_list);
|
|
/*
|
|
* The shadow_count has not changed.
|
|
*/
|
|
VM_OBJECT_WUNLOCK(backing_object->backing_object);
|
|
}
|
|
object->backing_object = backing_object->backing_object;
|
|
object->backing_object_offset +=
|
|
backing_object->backing_object_offset;
|
|
|
|
/*
|
|
* Discard backing_object.
|
|
*
|
|
* Since the backing object has no pages, no pager left,
|
|
* and no object references within it, all that is
|
|
* necessary is to dispose of it.
|
|
*/
|
|
KASSERT(backing_object->ref_count == 1, (
|
|
"backing_object %p was somehow re-referenced during collapse!",
|
|
backing_object));
|
|
VM_OBJECT_WUNLOCK(backing_object);
|
|
vm_object_destroy(backing_object);
|
|
|
|
object_collapses++;
|
|
} else {
|
|
vm_object_t new_backing_object;
|
|
|
|
/*
|
|
* If we do not entirely shadow the backing object,
|
|
* there is nothing we can do so we give up.
|
|
*/
|
|
if (object->resident_page_count != object->size &&
|
|
vm_object_backing_scan(object,
|
|
OBSC_TEST_ALL_SHADOWED) == 0) {
|
|
VM_OBJECT_WUNLOCK(backing_object);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Make the parent shadow the next object in the
|
|
* chain. Deallocating backing_object will not remove
|
|
* it, since its reference count is at least 2.
|
|
*/
|
|
LIST_REMOVE(object, shadow_list);
|
|
backing_object->shadow_count--;
|
|
|
|
new_backing_object = backing_object->backing_object;
|
|
if ((object->backing_object = new_backing_object) != NULL) {
|
|
VM_OBJECT_WLOCK(new_backing_object);
|
|
LIST_INSERT_HEAD(
|
|
&new_backing_object->shadow_head,
|
|
object,
|
|
shadow_list
|
|
);
|
|
new_backing_object->shadow_count++;
|
|
vm_object_reference_locked(new_backing_object);
|
|
VM_OBJECT_WUNLOCK(new_backing_object);
|
|
object->backing_object_offset +=
|
|
backing_object->backing_object_offset;
|
|
}
|
|
|
|
/*
|
|
* Drop the reference count on backing_object. Since
|
|
* its ref_count was at least 2, it will not vanish.
|
|
*/
|
|
backing_object->ref_count--;
|
|
VM_OBJECT_WUNLOCK(backing_object);
|
|
object_bypasses++;
|
|
}
|
|
|
|
/*
|
|
* Try again with this object's new backing object.
|
|
*/
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_object_page_remove:
|
|
*
|
|
* For the given object, either frees or invalidates each of the
|
|
* specified pages. In general, a page is freed. However, if a page is
|
|
* wired for any reason other than the existence of a managed, wired
|
|
* mapping, then it may be invalidated but not removed from the object.
|
|
* Pages are specified by the given range ["start", "end") and the option
|
|
* OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range
|
|
* extends from "start" to the end of the object. If the option
|
|
* OBJPR_CLEANONLY is specified, then only the non-dirty pages within the
|
|
* specified range are affected. If the option OBJPR_NOTMAPPED is
|
|
* specified, then the pages within the specified range must have no
|
|
* mappings. Otherwise, if this option is not specified, any mappings to
|
|
* the specified pages are removed before the pages are freed or
|
|
* invalidated.
|
|
*
|
|
* In general, this operation should only be performed on objects that
|
|
* contain managed pages. There are, however, two exceptions. First, it
|
|
* is performed on the kernel and kmem objects by vm_map_entry_delete().
|
|
* Second, it is used by msync(..., MS_INVALIDATE) to invalidate device-
|
|
* backed pages. In both of these cases, the option OBJPR_CLEANONLY must
|
|
* not be specified and the option OBJPR_NOTMAPPED must be specified.
|
|
*
|
|
* The object must be locked.
|
|
*/
|
|
void
|
|
vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
|
|
int options)
|
|
{
|
|
vm_page_t p, next;
|
|
int wirings;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
|
|
(options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED,
|
|
("vm_object_page_remove: illegal options for object %p", object));
|
|
if (object->resident_page_count == 0)
|
|
goto skipmemq;
|
|
vm_object_pip_add(object, 1);
|
|
again:
|
|
p = vm_page_find_least(object, start);
|
|
|
|
/*
|
|
* Here, the variable "p" is either (1) the page with the least pindex
|
|
* greater than or equal to the parameter "start" or (2) NULL.
|
|
*/
|
|
for (; p != NULL && (p->pindex < end || end == 0); p = next) {
|
|
next = TAILQ_NEXT(p, listq);
|
|
|
|
/*
|
|
* If the page is wired for any reason besides the existence
|
|
* of managed, wired mappings, then it cannot be freed. For
|
|
* example, fictitious pages, which represent device memory,
|
|
* are inherently wired and cannot be freed. They can,
|
|
* however, be invalidated if the option OBJPR_CLEANONLY is
|
|
* not specified.
|
|
*/
|
|
vm_page_lock(p);
|
|
if ((wirings = p->wire_count) != 0 &&
|
|
(wirings = pmap_page_wired_mappings(p)) != p->wire_count) {
|
|
if ((options & OBJPR_NOTMAPPED) == 0) {
|
|
pmap_remove_all(p);
|
|
/* Account for removal of wired mappings. */
|
|
if (wirings != 0)
|
|
p->wire_count -= wirings;
|
|
}
|
|
if ((options & OBJPR_CLEANONLY) == 0) {
|
|
p->valid = 0;
|
|
vm_page_undirty(p);
|
|
}
|
|
vm_page_unlock(p);
|
|
continue;
|
|
}
|
|
if (vm_page_sleep_if_busy(p, TRUE, "vmopar"))
|
|
goto again;
|
|
KASSERT((p->flags & PG_FICTITIOUS) == 0,
|
|
("vm_object_page_remove: page %p is fictitious", p));
|
|
if ((options & OBJPR_CLEANONLY) != 0 && p->valid != 0) {
|
|
if ((options & OBJPR_NOTMAPPED) == 0)
|
|
pmap_remove_write(p);
|
|
if (p->dirty) {
|
|
vm_page_unlock(p);
|
|
continue;
|
|
}
|
|
}
|
|
if ((options & OBJPR_NOTMAPPED) == 0) {
|
|
pmap_remove_all(p);
|
|
/* Account for removal of wired mappings. */
|
|
if (wirings != 0) {
|
|
KASSERT(p->wire_count == wirings,
|
|
("inconsistent wire count %d %d %p",
|
|
p->wire_count, wirings, p));
|
|
p->wire_count = 0;
|
|
atomic_subtract_int(&cnt.v_wire_count, 1);
|
|
}
|
|
}
|
|
vm_page_free(p);
|
|
vm_page_unlock(p);
|
|
}
|
|
vm_object_pip_wakeup(object);
|
|
skipmemq:
|
|
if (__predict_false(!vm_object_cache_is_empty(object)))
|
|
vm_page_cache_free(object, start, end);
|
|
}
|
|
|
|
/*
|
|
* vm_object_page_cache:
|
|
*
|
|
* For the given object, attempt to move the specified clean
|
|
* pages to the cache queue. If a page is wired for any reason,
|
|
* then it will not be changed. Pages are specified by the given
|
|
* range ["start", "end"). As a special case, if "end" is zero,
|
|
* then the range extends from "start" to the end of the object.
|
|
* Any mappings to the specified pages are removed before the
|
|
* pages are moved to the cache queue.
|
|
*
|
|
* This operation should only be performed on objects that
|
|
* contain non-fictitious, managed pages.
|
|
*
|
|
* The object must be locked.
|
|
*/
|
|
void
|
|
vm_object_page_cache(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
|
|
{
|
|
struct mtx *mtx, *new_mtx;
|
|
vm_page_t p, next;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0,
|
|
("vm_object_page_cache: illegal object %p", object));
|
|
if (object->resident_page_count == 0)
|
|
return;
|
|
p = vm_page_find_least(object, start);
|
|
|
|
/*
|
|
* Here, the variable "p" is either (1) the page with the least pindex
|
|
* greater than or equal to the parameter "start" or (2) NULL.
|
|
*/
|
|
mtx = NULL;
|
|
for (; p != NULL && (p->pindex < end || end == 0); p = next) {
|
|
next = TAILQ_NEXT(p, listq);
|
|
|
|
/*
|
|
* Avoid releasing and reacquiring the same page lock.
|
|
*/
|
|
new_mtx = vm_page_lockptr(p);
|
|
if (mtx != new_mtx) {
|
|
if (mtx != NULL)
|
|
mtx_unlock(mtx);
|
|
mtx = new_mtx;
|
|
mtx_lock(mtx);
|
|
}
|
|
vm_page_try_to_cache(p);
|
|
}
|
|
if (mtx != NULL)
|
|
mtx_unlock(mtx);
|
|
}
|
|
|
|
/*
|
|
* Populate the specified range of the object with valid pages. Returns
|
|
* TRUE if the range is successfully populated and FALSE otherwise.
|
|
*
|
|
* Note: This function should be optimized to pass a larger array of
|
|
* pages to vm_pager_get_pages() before it is applied to a non-
|
|
* OBJT_DEVICE object.
|
|
*
|
|
* The object must be locked.
|
|
*/
|
|
boolean_t
|
|
vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
|
|
{
|
|
vm_page_t m, ma[1];
|
|
vm_pindex_t pindex;
|
|
int rv;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
for (pindex = start; pindex < end; pindex++) {
|
|
m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL |
|
|
VM_ALLOC_RETRY);
|
|
if (m->valid != VM_PAGE_BITS_ALL) {
|
|
ma[0] = m;
|
|
rv = vm_pager_get_pages(object, ma, 1, 0);
|
|
m = vm_page_lookup(object, pindex);
|
|
if (m == NULL)
|
|
break;
|
|
if (rv != VM_PAGER_OK) {
|
|
vm_page_lock(m);
|
|
vm_page_free(m);
|
|
vm_page_unlock(m);
|
|
break;
|
|
}
|
|
}
|
|
/*
|
|
* Keep "m" busy because a subsequent iteration may unlock
|
|
* the object.
|
|
*/
|
|
}
|
|
if (pindex > start) {
|
|
m = vm_page_lookup(object, start);
|
|
while (m != NULL && m->pindex < pindex) {
|
|
vm_page_wakeup(m);
|
|
m = TAILQ_NEXT(m, listq);
|
|
}
|
|
}
|
|
return (pindex == end);
|
|
}
|
|
|
|
/*
|
|
* Routine: vm_object_coalesce
|
|
* Function: Coalesces two objects backing up adjoining
|
|
* regions of memory into a single object.
|
|
*
|
|
* returns TRUE if objects were combined.
|
|
*
|
|
* NOTE: Only works at the moment if the second object is NULL -
|
|
* if it's not, which object do we lock first?
|
|
*
|
|
* Parameters:
|
|
* prev_object First object to coalesce
|
|
* prev_offset Offset into prev_object
|
|
* prev_size Size of reference to prev_object
|
|
* next_size Size of reference to the second object
|
|
* reserved Indicator that extension region has
|
|
* swap accounted for
|
|
*
|
|
* Conditions:
|
|
* The object must *not* be locked.
|
|
*/
|
|
boolean_t
|
|
vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset,
|
|
vm_size_t prev_size, vm_size_t next_size, boolean_t reserved)
|
|
{
|
|
vm_pindex_t next_pindex;
|
|
|
|
if (prev_object == NULL)
|
|
return (TRUE);
|
|
VM_OBJECT_WLOCK(prev_object);
|
|
if (prev_object->type != OBJT_DEFAULT &&
|
|
prev_object->type != OBJT_SWAP) {
|
|
VM_OBJECT_WUNLOCK(prev_object);
|
|
return (FALSE);
|
|
}
|
|
|
|
/*
|
|
* Try to collapse the object first
|
|
*/
|
|
vm_object_collapse(prev_object);
|
|
|
|
/*
|
|
* Can't coalesce if: . more than one reference . paged out . shadows
|
|
* another object . has a copy elsewhere (any of which mean that the
|
|
* pages not mapped to prev_entry may be in use anyway)
|
|
*/
|
|
if (prev_object->backing_object != NULL) {
|
|
VM_OBJECT_WUNLOCK(prev_object);
|
|
return (FALSE);
|
|
}
|
|
|
|
prev_size >>= PAGE_SHIFT;
|
|
next_size >>= PAGE_SHIFT;
|
|
next_pindex = OFF_TO_IDX(prev_offset) + prev_size;
|
|
|
|
if ((prev_object->ref_count > 1) &&
|
|
(prev_object->size != next_pindex)) {
|
|
VM_OBJECT_WUNLOCK(prev_object);
|
|
return (FALSE);
|
|
}
|
|
|
|
/*
|
|
* Account for the charge.
|
|
*/
|
|
if (prev_object->cred != NULL) {
|
|
|
|
/*
|
|
* If prev_object was charged, then this mapping,
|
|
* althought not charged now, may become writable
|
|
* later. Non-NULL cred in the object would prevent
|
|
* swap reservation during enabling of the write
|
|
* access, so reserve swap now. Failed reservation
|
|
* cause allocation of the separate object for the map
|
|
* entry, and swap reservation for this entry is
|
|
* managed in appropriate time.
|
|
*/
|
|
if (!reserved && !swap_reserve_by_cred(ptoa(next_size),
|
|
prev_object->cred)) {
|
|
return (FALSE);
|
|
}
|
|
prev_object->charge += ptoa(next_size);
|
|
}
|
|
|
|
/*
|
|
* Remove any pages that may still be in the object from a previous
|
|
* deallocation.
|
|
*/
|
|
if (next_pindex < prev_object->size) {
|
|
vm_object_page_remove(prev_object, next_pindex, next_pindex +
|
|
next_size, 0);
|
|
if (prev_object->type == OBJT_SWAP)
|
|
swap_pager_freespace(prev_object,
|
|
next_pindex, next_size);
|
|
#if 0
|
|
if (prev_object->cred != NULL) {
|
|
KASSERT(prev_object->charge >=
|
|
ptoa(prev_object->size - next_pindex),
|
|
("object %p overcharged 1 %jx %jx", prev_object,
|
|
(uintmax_t)next_pindex, (uintmax_t)next_size));
|
|
prev_object->charge -= ptoa(prev_object->size -
|
|
next_pindex);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Extend the object if necessary.
|
|
*/
|
|
if (next_pindex + next_size > prev_object->size)
|
|
prev_object->size = next_pindex + next_size;
|
|
|
|
VM_OBJECT_WUNLOCK(prev_object);
|
|
return (TRUE);
|
|
}
|
|
|
|
void
|
|
vm_object_set_writeable_dirty(vm_object_t object)
|
|
{
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
if (object->type != OBJT_VNODE)
|
|
return;
|
|
object->generation++;
|
|
if ((object->flags & OBJ_MIGHTBEDIRTY) != 0)
|
|
return;
|
|
vm_object_set_flag(object, OBJ_MIGHTBEDIRTY);
|
|
}
|
|
|
|
#include "opt_ddb.h"
|
|
#ifdef DDB
|
|
#include <sys/kernel.h>
|
|
|
|
#include <sys/cons.h>
|
|
|
|
#include <ddb/ddb.h>
|
|
|
|
static int
|
|
_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
|
|
{
|
|
vm_map_t tmpm;
|
|
vm_map_entry_t tmpe;
|
|
vm_object_t obj;
|
|
int entcount;
|
|
|
|
if (map == 0)
|
|
return 0;
|
|
|
|
if (entry == 0) {
|
|
tmpe = map->header.next;
|
|
entcount = map->nentries;
|
|
while (entcount-- && (tmpe != &map->header)) {
|
|
if (_vm_object_in_map(map, object, tmpe)) {
|
|
return 1;
|
|
}
|
|
tmpe = tmpe->next;
|
|
}
|
|
} else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
|
|
tmpm = entry->object.sub_map;
|
|
tmpe = tmpm->header.next;
|
|
entcount = tmpm->nentries;
|
|
while (entcount-- && tmpe != &tmpm->header) {
|
|
if (_vm_object_in_map(tmpm, object, tmpe)) {
|
|
return 1;
|
|
}
|
|
tmpe = tmpe->next;
|
|
}
|
|
} else if ((obj = entry->object.vm_object) != NULL) {
|
|
for (; obj; obj = obj->backing_object)
|
|
if (obj == object) {
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
vm_object_in_map(vm_object_t object)
|
|
{
|
|
struct proc *p;
|
|
|
|
/* sx_slock(&allproc_lock); */
|
|
FOREACH_PROC_IN_SYSTEM(p) {
|
|
if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
|
|
continue;
|
|
if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
|
|
/* sx_sunlock(&allproc_lock); */
|
|
return 1;
|
|
}
|
|
}
|
|
/* sx_sunlock(&allproc_lock); */
|
|
if (_vm_object_in_map(kernel_map, object, 0))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
DB_SHOW_COMMAND(vmochk, vm_object_check)
|
|
{
|
|
vm_object_t object;
|
|
|
|
/*
|
|
* make sure that internal objs are in a map somewhere
|
|
* and none have zero ref counts.
|
|
*/
|
|
TAILQ_FOREACH(object, &vm_object_list, object_list) {
|
|
if (object->handle == NULL &&
|
|
(object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
|
|
if (object->ref_count == 0) {
|
|
db_printf("vmochk: internal obj has zero ref count: %ld\n",
|
|
(long)object->size);
|
|
}
|
|
if (!vm_object_in_map(object)) {
|
|
db_printf(
|
|
"vmochk: internal obj is not in a map: "
|
|
"ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
|
|
object->ref_count, (u_long)object->size,
|
|
(u_long)object->size,
|
|
(void *)object->backing_object);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_object_print: [ debug ]
|
|
*/
|
|
DB_SHOW_COMMAND(object, vm_object_print_static)
|
|
{
|
|
/* XXX convert args. */
|
|
vm_object_t object = (vm_object_t)addr;
|
|
boolean_t full = have_addr;
|
|
|
|
vm_page_t p;
|
|
|
|
/* XXX count is an (unused) arg. Avoid shadowing it. */
|
|
#define count was_count
|
|
|
|
int count;
|
|
|
|
if (object == NULL)
|
|
return;
|
|
|
|
db_iprintf(
|
|
"Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n",
|
|
object, (int)object->type, (uintmax_t)object->size,
|
|
object->resident_page_count, object->ref_count, object->flags,
|
|
object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge);
|
|
db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n",
|
|
object->shadow_count,
|
|
object->backing_object ? object->backing_object->ref_count : 0,
|
|
object->backing_object, (uintmax_t)object->backing_object_offset);
|
|
|
|
if (!full)
|
|
return;
|
|
|
|
db_indent += 2;
|
|
count = 0;
|
|
TAILQ_FOREACH(p, &object->memq, listq) {
|
|
if (count == 0)
|
|
db_iprintf("memory:=");
|
|
else if (count == 6) {
|
|
db_printf("\n");
|
|
db_iprintf(" ...");
|
|
count = 0;
|
|
} else
|
|
db_printf(",");
|
|
count++;
|
|
|
|
db_printf("(off=0x%jx,page=0x%jx)",
|
|
(uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p));
|
|
}
|
|
if (count != 0)
|
|
db_printf("\n");
|
|
db_indent -= 2;
|
|
}
|
|
|
|
/* XXX. */
|
|
#undef count
|
|
|
|
/* XXX need this non-static entry for calling from vm_map_print. */
|
|
void
|
|
vm_object_print(
|
|
/* db_expr_t */ long addr,
|
|
boolean_t have_addr,
|
|
/* db_expr_t */ long count,
|
|
char *modif)
|
|
{
|
|
vm_object_print_static(addr, have_addr, count, modif);
|
|
}
|
|
|
|
DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
|
|
{
|
|
vm_object_t object;
|
|
vm_pindex_t fidx;
|
|
vm_paddr_t pa;
|
|
vm_page_t m, prev_m;
|
|
int rcount, nl, c;
|
|
|
|
nl = 0;
|
|
TAILQ_FOREACH(object, &vm_object_list, object_list) {
|
|
db_printf("new object: %p\n", (void *)object);
|
|
if (nl > 18) {
|
|
c = cngetc();
|
|
if (c != ' ')
|
|
return;
|
|
nl = 0;
|
|
}
|
|
nl++;
|
|
rcount = 0;
|
|
fidx = 0;
|
|
pa = -1;
|
|
TAILQ_FOREACH(m, &object->memq, listq) {
|
|
if (m->pindex > 128)
|
|
break;
|
|
if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL &&
|
|
prev_m->pindex + 1 != m->pindex) {
|
|
if (rcount) {
|
|
db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
|
|
(long)fidx, rcount, (long)pa);
|
|
if (nl > 18) {
|
|
c = cngetc();
|
|
if (c != ' ')
|
|
return;
|
|
nl = 0;
|
|
}
|
|
nl++;
|
|
rcount = 0;
|
|
}
|
|
}
|
|
if (rcount &&
|
|
(VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
|
|
++rcount;
|
|
continue;
|
|
}
|
|
if (rcount) {
|
|
db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
|
|
(long)fidx, rcount, (long)pa);
|
|
if (nl > 18) {
|
|
c = cngetc();
|
|
if (c != ' ')
|
|
return;
|
|
nl = 0;
|
|
}
|
|
nl++;
|
|
}
|
|
fidx = m->pindex;
|
|
pa = VM_PAGE_TO_PHYS(m);
|
|
rcount = 1;
|
|
}
|
|
if (rcount) {
|
|
db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
|
|
(long)fidx, rcount, (long)pa);
|
|
if (nl > 18) {
|
|
c = cngetc();
|
|
if (c != ' ')
|
|
return;
|
|
nl = 0;
|
|
}
|
|
nl++;
|
|
}
|
|
}
|
|
}
|
|
#endif /* DDB */
|