/* * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * Copyright (c) 2003-2019 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * This code is derived from software contributed to The DragonFly Project * by Matthew Dillon <dillon@backplane.com> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Authors: Avadis Tevanian, Jr., Michael Wayne Young * * 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. */ /* * Resident memory system definitions. */ #ifndef _VM_VM_PAGE_H_ #define _VM_VM_PAGE_H_ #ifndef _SYS_TYPES_H_ #include <sys/types.h> #endif #ifndef _SYS_TREE_H_ #include <sys/tree.h> #endif #ifndef _MACHINE_PMAP_H_ #include <machine/pmap.h> #endif #ifndef _VM_PMAP_H_ #include <vm/pmap.h> #endif #include <machine/atomic.h> #ifdef _KERNEL #ifndef _SYS_SYSTM_H_ #include <sys/systm.h> #endif #ifndef _SYS_SPINLOCK_H_ #include <sys/spinlock.h> #endif #ifdef __x86_64__ #include <machine/vmparam.h> #endif #endif /* * The vm_page structure is the heart of the entire system. It's fairly * bulky, eating 3.125% of available memory (128 bytes vs 4K page size). * Most normal uses of the structure, representing physical memory, uses * the type-stable vm_page_array[]. Device mappings exposed to mmap() * (such as GPUs) generally use temporary vm_page's outside of this array * and will be flagged FICTITIOUS. Devices which use the kernel's contig * memory allocator get normal pages, but for convenience the pages will * be temporarily flagged as FICTITIOUS. * * Soft-busying or Hard-busying guarantees a stable m->object, m->pindex, * and m->valid field. A page cannot be validated or invalidated unless * hard-busied. * * The page must be hard-busied to make the following changes: * * (1) Any change to m->object or m->pindex (also requires the * related object to be exclusively locked). * * (2) Any transition of m->wire_count to 0 or from 0. Other * transitions (e.g. 2->1, 1->2, etc) are allowed without * locks. * * (3) Any change to m->valid. * * (4) Clearing PG_MAPPED or PG_WRITEABLE (note that because of * this, these bits may be left lazily set until they can * be cleared later on. * * Most other fields of the vm_page can change at any time with certain * restrictions. * * (1) PG_WRITEABLE and PG_MAPPED may be set with the page soft-busied * or hard-busied. * * (2) m->dirty may be set to VM_PAGE_BITS_ALL by a page fault at * any time if PG_WRITEABLE is flagged. Tests of m->dirty are * only tentative until all writeable mappings of the page are * removed. This may occur unlocked. A hard-busy is required * if modifying m->dirty under other conditions. * * (3) PG_REFERENCED may be set at any time by the pmap code to * synchronized the [A]ccessed bit, if PG_MAPPED is flagged, * unlocked. A hard-busy is required for any other time. * * (3) hold_count can be incremented or decremented at any time, * including transitions to or from 0. Holding a page via * vm_page_hold() does NOT stop major changes from being made * to the page, but WILL prevent the page from being freed * or reallocated. If the hold is emplaced with the page in * a known state it can prevent the underlying data from being * destroyed. * * (4) Each individual flag may have a different behavior. Some flags * can be set or cleared at any time, some require hard-busying, * etc. * * Moving the page between queues (aka m->pageq and m->queue) requires * m->spin to be exclusively locked first, and then also the spinlock related * to the queue. * * (1) This is the only use that requires m->spin any more. * * (2) There is one special case and that is the pageout daemon is * allowed to reorder the page within the same queue while just * holding the queue's spin-lock. * * Please see the flags section below for flag documentation. */ TAILQ_HEAD(pglist, vm_page); struct vm_object; int rb_vm_page_compare(struct vm_page *, struct vm_page *); struct vm_page_rb_tree; RB_PROTOTYPE2(vm_page_rb_tree, vm_page, rb_entry, rb_vm_page_compare, vm_pindex_t); RB_HEAD(vm_page_rb_tree, vm_page); struct vm_page { TAILQ_ENTRY(vm_page) pageq; /* vm_page_queues[] list */ RB_ENTRY(vm_page) rb_entry; /* Red-Black tree based at object */ struct spinlock spin; struct md_page md; /* machine dependant stuff */ uint32_t wire_count; /* wired down maps refs (P) */ uint32_t busy_count; /* soft-busy and hard-busy */ int hold_count; /* page hold count */ int ku_pagecnt; /* help kmalloc() w/oversized allocs */ struct vm_object *object; /* which object am I in */ vm_pindex_t pindex; /* offset into object */ vm_paddr_t phys_addr; /* physical address of page */ uint16_t queue; /* page queue index */ uint16_t pc; /* page color */ uint8_t act_count; /* page usage count */ uint8_t pat_mode; /* hardware page attribute */ uint8_t valid; /* map of valid DEV_BSIZE chunks */ uint8_t dirty; /* map of dirty DEV_BSIZE chunks */ uint32_t flags; /* see below */ int unused01; /* available */ /* 128 bytes */ #ifdef VM_PAGE_DEBUG const char *busy_func; int busy_line; #endif }; #define PBUSY_LOCKED 0x80000000U #define PBUSY_WANTED 0x40000000U #define PBUSY_SWAPINPROG 0x20000000U #define PBUSY_MASK 0x1FFFFFFFU #ifndef __VM_PAGE_T_DEFINED__ #define __VM_PAGE_T_DEFINED__ typedef struct vm_page *vm_page_t; #endif /* * Page coloring parameters. We use generous parameters designed to * statistically spread pages over available cpu cache space. This has * become less important over time as cache associativity is higher * in modern times but we still use the core algorithm to help reduce * lock contention between cpus. * * Page coloring cannot be disabled. * * In today's world of many-core systems, we must be able to provide enough VM * page queues for each logical cpu thread to cover the L1/L2/L3 cache set * associativity. If we don't, the cpu caches will not be properly utilized. * * Using 2048 allows 8-way set-assoc with 256 logical cpus, but seems to * have a number of downsides when queues are assymetrically starved. * * Using 1024 allows 4-way set-assoc with 256 logical cpus, and more with * fewer cpus. */ #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */ #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */ #define PQ_L2_SIZE 1024 /* Must be enough for maximal ncpus x hw set-assoc */ #define PQ_L2_MASK (PQ_L2_SIZE - 1) #define PQ_NONE 0 #define PQ_FREE (1 + 0*PQ_L2_SIZE) #define PQ_INACTIVE (1 + 1*PQ_L2_SIZE) #define PQ_ACTIVE (1 + 2*PQ_L2_SIZE) #define PQ_CACHE (1 + 3*PQ_L2_SIZE) #define PQ_HOLD (1 + 4*PQ_L2_SIZE) #define PQ_COUNT (1 + 5*PQ_L2_SIZE) /* * Scan support */ struct vm_map; struct rb_vm_page_scan_info { vm_pindex_t start_pindex; vm_pindex_t end_pindex; int limit; int desired; int error; int pagerflags; int count; int unused01; vm_offset_t addr; struct vm_map_entry *entry; struct vm_object *object; struct vm_object *dest_object; struct vm_page *mpte; struct pmap *pmap; struct vm_map *map; }; int rb_vm_page_scancmp(struct vm_page *, void *); struct vpgqueues { struct spinlock spin; struct pglist pl; long lcnt; long adds; /* heuristic, add operations */ int cnt_offset; /* offset into vmstats structure (int) */ int lastq; /* heuristic, skip empty queues */ } __aligned(64); extern struct vpgqueues vm_page_queues[PQ_COUNT]; /* * The m->flags field is generally categorized as follows. Unless otherwise * noted, a flag may only be updated while the page is hard-busied. * * PG_VPTMAPPED - Indicates that this page MIGHT be mapped via a * VPAGETABLE region. Used by vkernels. The backing_list * scan cannot find these mappings, so cooperative * invalidation via MADV_INVAL is required. * * PG_UNQUEUED - This prevents the page from being placed on any queue. * * PG_FICTITIOUS - This indicates to the pmap subsystem that the * page might not be reverse-addressable via * PHYS_TO_VM_PAGE(). The vm_page_t might be * temporary and not exist in the vm_page_array[]. * * This also generally means that the pmap subsystem * cannot synchronize the [M]odified and [A]ccessed * bits with the related vm_page_t, and in fact that * there might not even BE a related vm_page_t. * * Unlike the old system, the new pmap subsystem is * able to do bulk operations on virtual address ranges * containing fictitious pages, and can also pick-out * specific fictitious pages by matching m->phys_addr * if you supply a fake vm_page to it. * * Fictitious pages can still be organized into vm_objects * if desired. * * PG_MAPPED - Indicates that the page MIGHT be mapped into a pmap. * If not set, guarantees that the page is not mapped. * * This bit can be set unlocked but only cleared while * vm_page is hard-busied. * * For FICTITIOUS pages, this bit will be set automatically * via a page fault (aka pmap_enter()), but must be cleared * manually. * * PG_MAPPEDMULTI - Possibly mapped to multiple pmaps or to multiple locations * ine one pmap. * * PG_WRITEABLE - Indicates that the page MIGHT be writeable via a pte. * If not set, guarantees that the page is not writeable. * * This bit can be set unlocked but only cleared while * vm_page is hard-busied. * * For FICTITIOUS pages, this bit will be set automatically * via a page fault (aka pmap_enter()), but must be cleared * manually. * * PG_SWAPPED - Indicates that the page is backed by a swap block. * Any VM object type other than OBJT_DEFAULT can contain * swap-backed pages now. The bit may only be adjusted * while the page is hard-busied. * * PG_RAM - Heuristic read-ahead-marker. When I/O brings pages in, * this bit is set on one of them to force a page fault on * it to proactively read-ahead additional pages. * * Can be set or cleared at any time unlocked. * * PG_WINATCFLS - This is used to give dirty pages a second chance * on the inactive queue before getting flushed by * the pageout daemon. * * PG_REFERENCED - Indicates that the page has been accessed. If the * page is PG_MAPPED, this bit might not reflect the * actual state of the page. The pmap code synchronizes * the [A]ccessed bit to this flag and then clears the * [A]ccessed bit. * * PG_MARKER - Used by any queue-scanning code to recognize a fake * vm_page being used only as a scan marker. * * PG_NOTMETA - Distinguish pages representing content from pages * representing meta-data. * * PG_NEED_COMMIT - May only be modified while the page is hard-busied. * Indicates that even if the page might not appear to * be dirty, it must still be validated against some * remote entity (e.g. NFS) before it can be thrown away. * * PG_CLEANCHK - Used by the vm_object subsystem to detect pages that * might have been inserted during a scan. May be changed * at any time by the VM system (usually while holding the * related vm_object's lock). */ #if 0 #define PG_VPTMAPPED 0x00000001 /* mapped via VPAGETABLE */ #else #define PG_UNUSED0001 0x00000001 #endif #define PG_UNUSED0002 0x00000002 #define PG_WINATCFLS 0x00000004 /* flush dirty page on inactive q */ #define PG_FICTITIOUS 0x00000008 /* No reverse-map or tracking */ #define PG_WRITEABLE 0x00000010 /* page may be writeable */ #define PG_MAPPED 0x00000020 /* page may be mapped (managed) */ #define PG_MAPPEDMULTI 0x00000040 /* multiple mappings */ #define PG_REFERENCED 0x00000080 /* page has been referenced */ #define PG_CLEANCHK 0x00000100 /* page will be checked for cleaning */ #define PG_UNUSED0200 0x00000200 #define PG_NOSYNC 0x00000400 /* do not collect for syncer */ #define PG_UNQUEUED 0x00000800 /* No queue management for page */ #define PG_MARKER 0x00001000 /* special queue marker page */ #define PG_RAM 0x00002000 /* read ahead mark */ #define PG_SWAPPED 0x00004000 /* backed by swap */ #define PG_NOTMETA 0x00008000 /* do not back with swap */ #define PG_UNUSED10000 0x00010000 #define PG_UNUSED20000 0x00020000 #define PG_NEED_COMMIT 0x00040000 /* clean page requires commit */ #define PG_KEEP_NEWPAGE_MASK (0) /* * Misc constants. */ #define ACT_DECLINE 1 #define ACT_ADVANCE 3 #define ACT_INIT 5 #define ACT_MAX 64 #ifdef VM_PAGE_DEBUG #define VM_PAGE_DEBUG_EXT(name) name ## _debug #define VM_PAGE_DEBUG_ARGS , const char *func, int lineno #else #define VM_PAGE_DEBUG_EXT(name) name #define VM_PAGE_DEBUG_ARGS #endif #ifdef _KERNEL /* * Each pageable resident page falls into one of four lists: * * free * Available for allocation now. * * The following are all LRU sorted: * * cache * Almost available for allocation. Still in an * object, but clean and immediately freeable at * non-interrupt times. * * inactive * Low activity, candidates for reclamation. * This is the list of pages that should be * paged out next. * * active * Pages that are "active" i.e. they have been * recently referenced. * * zero * Pages that are really free and have been pre-zeroed * */ extern struct vm_page *vm_page_array; /* First resident page in table */ extern vm_pindex_t vm_page_array_size; /* number of vm_page_t's */ extern vm_pindex_t first_page; /* first physical page number */ #define VM_PAGE_TO_PHYS(entry) \ ((entry)->phys_addr) #define PHYS_TO_VM_PAGE(pa) \ (&vm_page_array[atop(pa) - first_page]) #if PAGE_SIZE == 4096 #define VM_PAGE_BITS_ALL 0xff #endif /* * Note: the code will always use nominally free pages from the free list * before trying other flag-specified sources. * * At least one of VM_ALLOC_NORMAL|VM_ALLOC_SYSTEM|VM_ALLOC_INTERRUPT * must be specified. VM_ALLOC_RETRY may only be specified if VM_ALLOC_NORMAL * is also specified. */ #define VM_ALLOC_NORMAL 0x0001 /* ok to use cache pages */ #define VM_ALLOC_SYSTEM 0x0002 /* ok to exhaust most of free list */ #define VM_ALLOC_INTERRUPT 0x0004 /* ok to exhaust entire free list */ #define VM_ALLOC_ZERO 0x0008 /* req pre-zero'd memory if avail */ #define VM_ALLOC_QUICK 0x0010 /* like NORMAL but do not use cache */ #define VM_ALLOC_FORCE_ZERO 0x0020 /* zero page even if already valid */ #define VM_ALLOC_NULL_OK 0x0040 /* ok to return NULL on collision */ #define VM_ALLOC_RETRY 0x0080 /* indefinite block (vm_page_grab()) */ #define VM_ALLOC_USE_GD 0x0100 /* use per-gd cache */ #define VM_ALLOC_CPU_SPEC 0x0200 #define VM_ALLOC_CPU_SHIFT 16 #define VM_ALLOC_CPU(n) (((n) << VM_ALLOC_CPU_SHIFT) | \ VM_ALLOC_CPU_SPEC) #define VM_ALLOC_GETCPU(flags) ((flags) >> VM_ALLOC_CPU_SHIFT) void vm_page_queue_spin_lock(vm_page_t); void vm_page_queues_spin_lock(u_short); void vm_page_and_queue_spin_lock(vm_page_t); void vm_page_queue_spin_unlock(vm_page_t); void vm_page_queues_spin_unlock(u_short); void vm_page_and_queue_spin_unlock(vm_page_t m); void vm_page_init(vm_page_t m); void vm_page_io_finish(vm_page_t m); void vm_page_io_start(vm_page_t m); void vm_page_need_commit(vm_page_t m); void vm_page_clear_commit(vm_page_t m); void vm_page_wakeup(vm_page_t m); void vm_page_hold(vm_page_t); void vm_page_unhold(vm_page_t); void vm_page_activate (vm_page_t); void vm_page_soft_activate (vm_page_t); vm_size_t vm_contig_avail_pages(void); vm_page_t vm_page_alloc (struct vm_object *, vm_pindex_t, int); vm_page_t vm_page_alloczwq (vm_pindex_t, int); void vm_page_freezwq (vm_page_t m); vm_page_t vm_page_alloc_contig(vm_paddr_t low, vm_paddr_t high, unsigned long alignment, unsigned long boundary, unsigned long size, vm_memattr_t memattr); vm_page_t vm_page_grab (struct vm_object *, vm_pindex_t, int); void vm_page_cache (vm_page_t); int vm_page_try_to_cache (vm_page_t); int vm_page_try_to_free (vm_page_t); void vm_page_dontneed (vm_page_t); void vm_page_deactivate (vm_page_t); void vm_page_deactivate_locked (vm_page_t); void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr); int vm_page_insert (vm_page_t, struct vm_object *, vm_pindex_t); vm_page_t vm_page_hash_get(vm_object_t object, vm_pindex_t pindex); vm_page_t vm_page_lookup (struct vm_object *, vm_pindex_t); vm_page_t vm_page_lookup_sbusy_try(struct vm_object *object, vm_pindex_t pindex, int pgoff, int pgbytes); vm_page_t VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_wait)( struct vm_object *, vm_pindex_t, int, const char * VM_PAGE_DEBUG_ARGS); vm_page_t VM_PAGE_DEBUG_EXT(vm_page_lookup_busy_try)( struct vm_object *, vm_pindex_t, int, int * VM_PAGE_DEBUG_ARGS); void vm_page_remove (vm_page_t); void vm_page_rename (vm_page_t, struct vm_object *, vm_pindex_t); void vm_page_startup (void); void vm_numa_organize(vm_paddr_t ran_beg, vm_paddr_t bytes, int physid); void vm_numa_organize_finalize(void); void vm_page_unwire (vm_page_t, int); void vm_page_wire (vm_page_t); void vm_page_unqueue (vm_page_t); void vm_page_unqueue_nowakeup (vm_page_t); vm_page_t vm_page_next (vm_page_t); void vm_page_set_validclean (vm_page_t, int, int); void vm_page_set_validdirty (vm_page_t, int, int); void vm_page_set_valid (vm_page_t, int, int); void vm_page_set_dirty (vm_page_t, int, int); void vm_page_clear_dirty (vm_page_t, int, int); void vm_page_set_invalid (vm_page_t, int, int); int vm_page_is_valid (vm_page_t, int, int); void vm_page_test_dirty (vm_page_t); int vm_page_bits (int, int); vm_page_t vm_page_list_find(int basequeue, int index); void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid); void vm_page_free_toq(vm_page_t m); void vm_page_free_contig(vm_page_t m, unsigned long size); vm_page_t vm_page_free_fromq_fast(void); void vm_page_dirty(vm_page_t m); void vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg); int vm_page_sbusy_try(vm_page_t m); void VM_PAGE_DEBUG_EXT(vm_page_busy_wait)(vm_page_t m, int also_m_busy, const char *wmsg VM_PAGE_DEBUG_ARGS); int VM_PAGE_DEBUG_EXT(vm_page_busy_try)(vm_page_t m, int also_m_busy VM_PAGE_DEBUG_ARGS); u_short vm_get_pg_color(int cpuid, vm_object_t object, vm_pindex_t pindex); #ifdef VM_PAGE_DEBUG #define vm_page_lookup_busy_wait(object, pindex, alsob, msg) \ vm_page_lookup_busy_wait_debug(object, pindex, alsob, msg, \ __func__, __LINE__) #define vm_page_lookup_busy_try(object, pindex, alsob, errorp) \ vm_page_lookup_busy_try_debug(object, pindex, alsob, errorp, \ __func__, __LINE__) #define vm_page_busy_wait(m, alsob, msg) \ vm_page_busy_wait_debug(m, alsob, msg, __func__, __LINE__) #define vm_page_busy_try(m, alsob) \ vm_page_busy_try_debug(m, alsob, __func__, __LINE__) #endif #endif /* _KERNEL */ #endif /* !_VM_VM_PAGE_H_ */
