1159 lines
33 KiB
C
1159 lines
33 KiB
C
/*-
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* Copyright (c) 2002-2006 Rice University
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* Copyright (c) 2007-2011 Alan L. Cox <alc@cs.rice.edu>
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* All rights reserved.
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*
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* This software was developed for the FreeBSD Project by Alan L. Cox,
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* Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
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* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Superpage reservation management module
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*
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* Any external functions defined by this module are only to be used by the
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* virtual memory system.
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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/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/queue.h>
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#include <sys/rwlock.h>
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#include <sys/sbuf.h>
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#include <sys/sysctl.h>
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#include <sys/systm.h>
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#include <vm/vm.h>
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#include <vm/vm_param.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_phys.h>
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#include <vm/vm_radix.h>
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#include <vm/vm_reserv.h>
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/*
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* The reservation system supports the speculative allocation of large physical
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* pages ("superpages"). Speculative allocation enables the fully-automatic
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* utilization of superpages by the virtual memory system. In other words, no
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* programmatic directives are required to use superpages.
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*/
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#if VM_NRESERVLEVEL > 0
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/*
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* The number of small pages that are contained in a level 0 reservation
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*/
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#define VM_LEVEL_0_NPAGES (1 << VM_LEVEL_0_ORDER)
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/*
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* The number of bits by which a physical address is shifted to obtain the
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* reservation number
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*/
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#define VM_LEVEL_0_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
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/*
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* The size of a level 0 reservation in bytes
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*/
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#define VM_LEVEL_0_SIZE (1 << VM_LEVEL_0_SHIFT)
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/*
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* Computes the index of the small page underlying the given (object, pindex)
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* within the reservation's array of small pages.
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*/
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#define VM_RESERV_INDEX(object, pindex) \
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(((object)->pg_color + (pindex)) & (VM_LEVEL_0_NPAGES - 1))
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/*
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* The size of a population map entry
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*/
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typedef u_long popmap_t;
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/*
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* The number of bits in a population map entry
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*/
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#define NBPOPMAP (NBBY * sizeof(popmap_t))
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/*
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* The number of population map entries in a reservation
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*/
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#define NPOPMAP howmany(VM_LEVEL_0_NPAGES, NBPOPMAP)
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/*
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* Clear a bit in the population map.
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*/
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static __inline void
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popmap_clear(popmap_t popmap[], int i)
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{
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popmap[i / NBPOPMAP] &= ~(1UL << (i % NBPOPMAP));
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}
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/*
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* Set a bit in the population map.
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*/
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static __inline void
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popmap_set(popmap_t popmap[], int i)
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{
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popmap[i / NBPOPMAP] |= 1UL << (i % NBPOPMAP);
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}
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/*
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* Is a bit in the population map clear?
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*/
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static __inline boolean_t
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popmap_is_clear(popmap_t popmap[], int i)
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{
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return ((popmap[i / NBPOPMAP] & (1UL << (i % NBPOPMAP))) == 0);
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}
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/*
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* Is a bit in the population map set?
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*/
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static __inline boolean_t
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popmap_is_set(popmap_t popmap[], int i)
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{
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return ((popmap[i / NBPOPMAP] & (1UL << (i % NBPOPMAP))) != 0);
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}
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/*
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* The reservation structure
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*
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* A reservation structure is constructed whenever a large physical page is
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* speculatively allocated to an object. The reservation provides the small
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* physical pages for the range [pindex, pindex + VM_LEVEL_0_NPAGES) of offsets
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* within that object. The reservation's "popcnt" tracks the number of these
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* small physical pages that are in use at any given time. When and if the
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* reservation is not fully utilized, it appears in the queue of partially-
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* populated reservations. The reservation always appears on the containing
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* object's list of reservations.
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*
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* A partially-populated reservation can be broken and reclaimed at any time.
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*/
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struct vm_reserv {
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TAILQ_ENTRY(vm_reserv) partpopq;
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LIST_ENTRY(vm_reserv) objq;
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vm_object_t object; /* containing object */
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vm_pindex_t pindex; /* offset within object */
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vm_page_t pages; /* first page of a superpage */
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int popcnt; /* # of pages in use */
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char inpartpopq;
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popmap_t popmap[NPOPMAP]; /* bit vector of used pages */
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};
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/*
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* The reservation array
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*
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* This array is analoguous in function to vm_page_array. It differs in the
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* respect that it may contain a greater number of useful reservation
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* structures than there are (physical) superpages. These "invalid"
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* reservation structures exist to trade-off space for time in the
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* implementation of vm_reserv_from_page(). Invalid reservation structures are
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* distinguishable from "valid" reservation structures by inspecting the
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* reservation's "pages" field. Invalid reservation structures have a NULL
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* "pages" field.
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*
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* vm_reserv_from_page() maps a small (physical) page to an element of this
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* array by computing a physical reservation number from the page's physical
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* address. The physical reservation number is used as the array index.
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*
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* An "active" reservation is a valid reservation structure that has a non-NULL
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* "object" field and a non-zero "popcnt" field. In other words, every active
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* reservation belongs to a particular object. Moreover, every active
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* reservation has an entry in the containing object's list of reservations.
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*/
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static vm_reserv_t vm_reserv_array;
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/*
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* The partially-populated reservation queue
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*
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* This queue enables the fast recovery of an unused cached or free small page
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* from a partially-populated reservation. The reservation at the head of
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* this queue is the least-recently-changed, partially-populated reservation.
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*
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* Access to this queue is synchronized by the free page queue lock.
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*/
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static TAILQ_HEAD(, vm_reserv) vm_rvq_partpop =
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TAILQ_HEAD_INITIALIZER(vm_rvq_partpop);
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static SYSCTL_NODE(_vm, OID_AUTO, reserv, CTLFLAG_RD, 0, "Reservation Info");
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static long vm_reserv_broken;
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SYSCTL_LONG(_vm_reserv, OID_AUTO, broken, CTLFLAG_RD,
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&vm_reserv_broken, 0, "Cumulative number of broken reservations");
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static long vm_reserv_freed;
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SYSCTL_LONG(_vm_reserv, OID_AUTO, freed, CTLFLAG_RD,
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&vm_reserv_freed, 0, "Cumulative number of freed reservations");
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static int sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS);
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SYSCTL_PROC(_vm_reserv, OID_AUTO, fullpop, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
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sysctl_vm_reserv_fullpop, "I", "Current number of full reservations");
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static int sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS);
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SYSCTL_OID(_vm_reserv, OID_AUTO, partpopq, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0,
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sysctl_vm_reserv_partpopq, "A", "Partially-populated reservation queues");
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static long vm_reserv_reclaimed;
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SYSCTL_LONG(_vm_reserv, OID_AUTO, reclaimed, CTLFLAG_RD,
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&vm_reserv_reclaimed, 0, "Cumulative number of reclaimed reservations");
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static void vm_reserv_break(vm_reserv_t rv, vm_page_t m);
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static void vm_reserv_depopulate(vm_reserv_t rv, int index);
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static vm_reserv_t vm_reserv_from_page(vm_page_t m);
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static boolean_t vm_reserv_has_pindex(vm_reserv_t rv,
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vm_pindex_t pindex);
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static void vm_reserv_populate(vm_reserv_t rv, int index);
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static void vm_reserv_reclaim(vm_reserv_t rv);
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/*
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* Returns the current number of full reservations.
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*
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* Since the number of full reservations is computed without acquiring the
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* free page queue lock, the returned value may be inexact.
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*/
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static int
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sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS)
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{
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vm_paddr_t paddr;
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struct vm_phys_seg *seg;
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vm_reserv_t rv;
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int fullpop, segind;
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fullpop = 0;
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for (segind = 0; segind < vm_phys_nsegs; segind++) {
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seg = &vm_phys_segs[segind];
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paddr = roundup2(seg->start, VM_LEVEL_0_SIZE);
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while (paddr + VM_LEVEL_0_SIZE <= seg->end) {
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rv = &vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT];
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fullpop += rv->popcnt == VM_LEVEL_0_NPAGES;
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paddr += VM_LEVEL_0_SIZE;
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}
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}
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return (sysctl_handle_int(oidp, &fullpop, 0, req));
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}
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/*
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* Describes the current state of the partially-populated reservation queue.
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*/
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static int
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sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS)
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{
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struct sbuf sbuf;
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vm_reserv_t rv;
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int counter, error, level, unused_pages;
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error = sysctl_wire_old_buffer(req, 0);
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if (error != 0)
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return (error);
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sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
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sbuf_printf(&sbuf, "\nLEVEL SIZE NUMBER\n\n");
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for (level = -1; level <= VM_NRESERVLEVEL - 2; level++) {
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counter = 0;
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unused_pages = 0;
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mtx_lock(&vm_page_queue_free_mtx);
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TAILQ_FOREACH(rv, &vm_rvq_partpop/*[level]*/, partpopq) {
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counter++;
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unused_pages += VM_LEVEL_0_NPAGES - rv->popcnt;
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}
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mtx_unlock(&vm_page_queue_free_mtx);
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sbuf_printf(&sbuf, "%5d: %6dK, %6d\n", level,
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unused_pages * ((int)PAGE_SIZE / 1024), counter);
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}
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error = sbuf_finish(&sbuf);
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sbuf_delete(&sbuf);
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return (error);
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}
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/*
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* Reduces the given reservation's population count. If the population count
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* becomes zero, the reservation is destroyed. Additionally, moves the
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* reservation to the tail of the partially-populated reservation queue if the
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* population count is non-zero.
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*
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* The free page queue lock must be held.
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*/
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static void
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vm_reserv_depopulate(vm_reserv_t rv, int index)
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{
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mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
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KASSERT(rv->object != NULL,
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("vm_reserv_depopulate: reserv %p is free", rv));
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KASSERT(popmap_is_set(rv->popmap, index),
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("vm_reserv_depopulate: reserv %p's popmap[%d] is clear", rv,
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index));
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KASSERT(rv->popcnt > 0,
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("vm_reserv_depopulate: reserv %p's popcnt is corrupted", rv));
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if (rv->inpartpopq) {
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TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
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rv->inpartpopq = FALSE;
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} else {
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KASSERT(rv->pages->psind == 1,
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("vm_reserv_depopulate: reserv %p is already demoted",
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rv));
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rv->pages->psind = 0;
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}
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popmap_clear(rv->popmap, index);
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rv->popcnt--;
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if (rv->popcnt == 0) {
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LIST_REMOVE(rv, objq);
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rv->object = NULL;
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vm_phys_free_pages(rv->pages, VM_LEVEL_0_ORDER);
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vm_reserv_freed++;
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} else {
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rv->inpartpopq = TRUE;
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TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq);
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}
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}
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/*
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* Returns the reservation to which the given page might belong.
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*/
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static __inline vm_reserv_t
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vm_reserv_from_page(vm_page_t m)
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{
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return (&vm_reserv_array[VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT]);
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}
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/*
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* Returns TRUE if the given reservation contains the given page index and
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* FALSE otherwise.
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*/
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static __inline boolean_t
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vm_reserv_has_pindex(vm_reserv_t rv, vm_pindex_t pindex)
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{
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return (((pindex - rv->pindex) & ~(VM_LEVEL_0_NPAGES - 1)) == 0);
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}
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/*
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* Increases the given reservation's population count. Moves the reservation
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* to the tail of the partially-populated reservation queue.
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*
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* The free page queue must be locked.
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*/
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static void
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vm_reserv_populate(vm_reserv_t rv, int index)
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{
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mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
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KASSERT(rv->object != NULL,
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("vm_reserv_populate: reserv %p is free", rv));
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KASSERT(popmap_is_clear(rv->popmap, index),
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("vm_reserv_populate: reserv %p's popmap[%d] is set", rv,
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index));
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KASSERT(rv->popcnt < VM_LEVEL_0_NPAGES,
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("vm_reserv_populate: reserv %p is already full", rv));
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KASSERT(rv->pages->psind == 0,
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("vm_reserv_populate: reserv %p is already promoted", rv));
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if (rv->inpartpopq) {
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TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
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rv->inpartpopq = FALSE;
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}
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popmap_set(rv->popmap, index);
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rv->popcnt++;
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if (rv->popcnt < VM_LEVEL_0_NPAGES) {
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rv->inpartpopq = TRUE;
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TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq);
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} else
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rv->pages->psind = 1;
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}
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/*
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* Allocates a contiguous set of physical pages of the given size "npages"
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* from existing or newly created reservations. All of the physical pages
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* must be at or above the given physical address "low" and below the given
|
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* physical address "high". The given value "alignment" determines the
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* alignment of the first physical page in the set. If the given value
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* "boundary" is non-zero, then the set of physical pages cannot cross any
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* physical address boundary that is a multiple of that value. Both
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* "alignment" and "boundary" must be a power of two.
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*
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* The object and free page queue must be locked.
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*/
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vm_page_t
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vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages,
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vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
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{
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vm_paddr_t pa, size;
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vm_page_t m, m_ret, mpred, msucc;
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vm_pindex_t first, leftcap, rightcap;
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vm_reserv_t rv;
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u_long allocpages, maxpages, minpages;
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int i, index, n;
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mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
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VM_OBJECT_ASSERT_WLOCKED(object);
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KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0"));
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|
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/*
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* Is a reservation fundamentally impossible?
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*/
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if (pindex < VM_RESERV_INDEX(object, pindex) ||
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pindex + npages > object->size)
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return (NULL);
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|
|
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/*
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* All reservations of a particular size have the same alignment.
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* Assuming that the first page is allocated from a reservation, the
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* least significant bits of its physical address can be determined
|
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* from its offset from the beginning of the reservation and the size
|
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* of the reservation.
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*
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* Could the specified index within a reservation of the smallest
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* possible size satisfy the alignment and boundary requirements?
|
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*/
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pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT;
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if ((pa & (alignment - 1)) != 0)
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return (NULL);
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size = npages << PAGE_SHIFT;
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if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0)
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return (NULL);
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|
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/*
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* Look for an existing reservation.
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*/
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mpred = vm_radix_lookup_le(&object->rtree, pindex);
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if (mpred != NULL) {
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KASSERT(mpred->pindex < pindex,
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("vm_reserv_alloc_contig: pindex already allocated"));
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rv = vm_reserv_from_page(mpred);
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if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
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goto found;
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msucc = TAILQ_NEXT(mpred, listq);
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} else
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msucc = TAILQ_FIRST(&object->memq);
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if (msucc != NULL) {
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KASSERT(msucc->pindex > pindex,
|
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("vm_reserv_alloc_contig: pindex already allocated"));
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rv = vm_reserv_from_page(msucc);
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if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
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goto found;
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}
|
|
|
|
/*
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* Could at least one reservation fit between the first index to the
|
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* left that can be used ("leftcap") and the first index to the right
|
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* that cannot be used ("rightcap")?
|
|
*/
|
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first = pindex - VM_RESERV_INDEX(object, pindex);
|
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if (mpred != NULL) {
|
|
if ((rv = vm_reserv_from_page(mpred))->object != object)
|
|
leftcap = mpred->pindex + 1;
|
|
else
|
|
leftcap = rv->pindex + VM_LEVEL_0_NPAGES;
|
|
if (leftcap > first)
|
|
return (NULL);
|
|
}
|
|
minpages = VM_RESERV_INDEX(object, pindex) + npages;
|
|
maxpages = roundup2(minpages, VM_LEVEL_0_NPAGES);
|
|
allocpages = maxpages;
|
|
if (msucc != NULL) {
|
|
if ((rv = vm_reserv_from_page(msucc))->object != object)
|
|
rightcap = msucc->pindex;
|
|
else
|
|
rightcap = rv->pindex;
|
|
if (first + maxpages > rightcap) {
|
|
if (maxpages == VM_LEVEL_0_NPAGES)
|
|
return (NULL);
|
|
|
|
/*
|
|
* At least one reservation will fit between "leftcap"
|
|
* and "rightcap". However, a reservation for the
|
|
* last of the requested pages will not fit. Reduce
|
|
* the size of the upcoming allocation accordingly.
|
|
*/
|
|
allocpages = minpages;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Would the last new reservation extend past the end of the object?
|
|
*/
|
|
if (first + maxpages > object->size) {
|
|
/*
|
|
* Don't allocate the last new reservation if the object is a
|
|
* vnode or backed by another object that is a vnode.
|
|
*/
|
|
if (object->type == OBJT_VNODE ||
|
|
(object->backing_object != NULL &&
|
|
object->backing_object->type == OBJT_VNODE)) {
|
|
if (maxpages == VM_LEVEL_0_NPAGES)
|
|
return (NULL);
|
|
allocpages = minpages;
|
|
}
|
|
/* Speculate that the object may grow. */
|
|
}
|
|
|
|
/*
|
|
* Allocate the physical pages. The alignment and boundary specified
|
|
* for this allocation may be different from the alignment and
|
|
* boundary specified for the requested pages. For instance, the
|
|
* specified index may not be the first page within the first new
|
|
* reservation.
|
|
*/
|
|
m = vm_phys_alloc_contig(allocpages, low, high, ulmax(alignment,
|
|
VM_LEVEL_0_SIZE), boundary > VM_LEVEL_0_SIZE ? boundary : 0);
|
|
if (m == NULL)
|
|
return (NULL);
|
|
|
|
/*
|
|
* The allocated physical pages always begin at a reservation
|
|
* boundary, but they do not always end at a reservation boundary.
|
|
* Initialize every reservation that is completely covered by the
|
|
* allocated physical pages.
|
|
*/
|
|
m_ret = NULL;
|
|
index = VM_RESERV_INDEX(object, pindex);
|
|
do {
|
|
rv = vm_reserv_from_page(m);
|
|
KASSERT(rv->pages == m,
|
|
("vm_reserv_alloc_contig: reserv %p's pages is corrupted",
|
|
rv));
|
|
KASSERT(rv->object == NULL,
|
|
("vm_reserv_alloc_contig: reserv %p isn't free", rv));
|
|
LIST_INSERT_HEAD(&object->rvq, rv, objq);
|
|
rv->object = object;
|
|
rv->pindex = first;
|
|
KASSERT(rv->popcnt == 0,
|
|
("vm_reserv_alloc_contig: reserv %p's popcnt is corrupted",
|
|
rv));
|
|
KASSERT(!rv->inpartpopq,
|
|
("vm_reserv_alloc_contig: reserv %p's inpartpopq is TRUE",
|
|
rv));
|
|
for (i = 0; i < NPOPMAP; i++)
|
|
KASSERT(rv->popmap[i] == 0,
|
|
("vm_reserv_alloc_contig: reserv %p's popmap is corrupted",
|
|
rv));
|
|
n = ulmin(VM_LEVEL_0_NPAGES - index, npages);
|
|
for (i = 0; i < n; i++)
|
|
vm_reserv_populate(rv, index + i);
|
|
npages -= n;
|
|
if (m_ret == NULL) {
|
|
m_ret = &rv->pages[index];
|
|
index = 0;
|
|
}
|
|
m += VM_LEVEL_0_NPAGES;
|
|
first += VM_LEVEL_0_NPAGES;
|
|
allocpages -= VM_LEVEL_0_NPAGES;
|
|
} while (allocpages >= VM_LEVEL_0_NPAGES);
|
|
return (m_ret);
|
|
|
|
/*
|
|
* Found a matching reservation.
|
|
*/
|
|
found:
|
|
index = VM_RESERV_INDEX(object, pindex);
|
|
/* Does the allocation fit within the reservation? */
|
|
if (index + npages > VM_LEVEL_0_NPAGES)
|
|
return (NULL);
|
|
m = &rv->pages[index];
|
|
pa = VM_PAGE_TO_PHYS(m);
|
|
if (pa < low || pa + size > high || (pa & (alignment - 1)) != 0 ||
|
|
((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0)
|
|
return (NULL);
|
|
/* Handle vm_page_rename(m, new_object, ...). */
|
|
for (i = 0; i < npages; i++)
|
|
if (popmap_is_set(rv->popmap, index + i))
|
|
return (NULL);
|
|
for (i = 0; i < npages; i++)
|
|
vm_reserv_populate(rv, index + i);
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* Allocates a page from an existing or newly-created reservation.
|
|
*
|
|
* The page "mpred" must immediately precede the offset "pindex" within the
|
|
* specified object.
|
|
*
|
|
* The object and free page queue must be locked.
|
|
*/
|
|
vm_page_t
|
|
vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, vm_page_t mpred)
|
|
{
|
|
vm_page_t m, msucc;
|
|
vm_pindex_t first, leftcap, rightcap;
|
|
vm_reserv_t rv;
|
|
int i, index;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
|
|
/*
|
|
* Is a reservation fundamentally impossible?
|
|
*/
|
|
if (pindex < VM_RESERV_INDEX(object, pindex) ||
|
|
pindex >= object->size)
|
|
return (NULL);
|
|
|
|
/*
|
|
* Look for an existing reservation.
|
|
*/
|
|
if (mpred != NULL) {
|
|
KASSERT(mpred->object == object,
|
|
("vm_reserv_alloc_page: object doesn't contain mpred"));
|
|
KASSERT(mpred->pindex < pindex,
|
|
("vm_reserv_alloc_page: mpred doesn't precede pindex"));
|
|
rv = vm_reserv_from_page(mpred);
|
|
if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
|
|
goto found;
|
|
msucc = TAILQ_NEXT(mpred, listq);
|
|
} else
|
|
msucc = TAILQ_FIRST(&object->memq);
|
|
if (msucc != NULL) {
|
|
KASSERT(msucc->pindex > pindex,
|
|
("vm_reserv_alloc_page: msucc doesn't succeed pindex"));
|
|
rv = vm_reserv_from_page(msucc);
|
|
if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
|
|
goto found;
|
|
}
|
|
|
|
/*
|
|
* Could a reservation fit between the first index to the left that
|
|
* can be used and the first index to the right that cannot be used?
|
|
*/
|
|
first = pindex - VM_RESERV_INDEX(object, pindex);
|
|
if (mpred != NULL) {
|
|
if ((rv = vm_reserv_from_page(mpred))->object != object)
|
|
leftcap = mpred->pindex + 1;
|
|
else
|
|
leftcap = rv->pindex + VM_LEVEL_0_NPAGES;
|
|
if (leftcap > first)
|
|
return (NULL);
|
|
}
|
|
if (msucc != NULL) {
|
|
if ((rv = vm_reserv_from_page(msucc))->object != object)
|
|
rightcap = msucc->pindex;
|
|
else
|
|
rightcap = rv->pindex;
|
|
if (first + VM_LEVEL_0_NPAGES > rightcap)
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* Would a new reservation extend past the end of the object?
|
|
*/
|
|
if (first + VM_LEVEL_0_NPAGES > object->size) {
|
|
/*
|
|
* Don't allocate a new reservation if the object is a vnode or
|
|
* backed by another object that is a vnode.
|
|
*/
|
|
if (object->type == OBJT_VNODE ||
|
|
(object->backing_object != NULL &&
|
|
object->backing_object->type == OBJT_VNODE))
|
|
return (NULL);
|
|
/* Speculate that the object may grow. */
|
|
}
|
|
|
|
/*
|
|
* Allocate and populate the new reservation.
|
|
*/
|
|
m = vm_phys_alloc_pages(VM_FREEPOOL_DEFAULT, VM_LEVEL_0_ORDER);
|
|
if (m == NULL)
|
|
return (NULL);
|
|
rv = vm_reserv_from_page(m);
|
|
KASSERT(rv->pages == m,
|
|
("vm_reserv_alloc_page: reserv %p's pages is corrupted", rv));
|
|
KASSERT(rv->object == NULL,
|
|
("vm_reserv_alloc_page: reserv %p isn't free", rv));
|
|
LIST_INSERT_HEAD(&object->rvq, rv, objq);
|
|
rv->object = object;
|
|
rv->pindex = first;
|
|
KASSERT(rv->popcnt == 0,
|
|
("vm_reserv_alloc_page: reserv %p's popcnt is corrupted", rv));
|
|
KASSERT(!rv->inpartpopq,
|
|
("vm_reserv_alloc_page: reserv %p's inpartpopq is TRUE", rv));
|
|
for (i = 0; i < NPOPMAP; i++)
|
|
KASSERT(rv->popmap[i] == 0,
|
|
("vm_reserv_alloc_page: reserv %p's popmap is corrupted",
|
|
rv));
|
|
index = VM_RESERV_INDEX(object, pindex);
|
|
vm_reserv_populate(rv, index);
|
|
return (&rv->pages[index]);
|
|
|
|
/*
|
|
* Found a matching reservation.
|
|
*/
|
|
found:
|
|
index = VM_RESERV_INDEX(object, pindex);
|
|
m = &rv->pages[index];
|
|
/* Handle vm_page_rename(m, new_object, ...). */
|
|
if (popmap_is_set(rv->popmap, index))
|
|
return (NULL);
|
|
vm_reserv_populate(rv, index);
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* Breaks the given reservation. Except for the specified cached or free
|
|
* page, all cached and free pages in the reservation are returned to the
|
|
* physical memory allocator. The reservation's population count and map are
|
|
* reset to their initial state.
|
|
*
|
|
* The given reservation must not be in the partially-populated reservation
|
|
* queue. The free page queue lock must be held.
|
|
*/
|
|
static void
|
|
vm_reserv_break(vm_reserv_t rv, vm_page_t m)
|
|
{
|
|
int begin_zeroes, hi, i, lo;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
KASSERT(rv->object != NULL,
|
|
("vm_reserv_break: reserv %p is free", rv));
|
|
KASSERT(!rv->inpartpopq,
|
|
("vm_reserv_break: reserv %p's inpartpopq is TRUE", rv));
|
|
LIST_REMOVE(rv, objq);
|
|
rv->object = NULL;
|
|
if (m != NULL) {
|
|
/*
|
|
* Since the reservation is being broken, there is no harm in
|
|
* abusing the population map to stop "m" from being returned
|
|
* to the physical memory allocator.
|
|
*/
|
|
i = m - rv->pages;
|
|
KASSERT(popmap_is_clear(rv->popmap, i),
|
|
("vm_reserv_break: reserv %p's popmap is corrupted", rv));
|
|
popmap_set(rv->popmap, i);
|
|
rv->popcnt++;
|
|
}
|
|
i = hi = 0;
|
|
do {
|
|
/* Find the next 0 bit. Any previous 0 bits are < "hi". */
|
|
lo = ffsl(~(((1UL << hi) - 1) | rv->popmap[i]));
|
|
if (lo == 0) {
|
|
/* Redundantly clears bits < "hi". */
|
|
rv->popmap[i] = 0;
|
|
rv->popcnt -= NBPOPMAP - hi;
|
|
while (++i < NPOPMAP) {
|
|
lo = ffsl(~rv->popmap[i]);
|
|
if (lo == 0) {
|
|
rv->popmap[i] = 0;
|
|
rv->popcnt -= NBPOPMAP;
|
|
} else
|
|
break;
|
|
}
|
|
if (i == NPOPMAP)
|
|
break;
|
|
hi = 0;
|
|
}
|
|
KASSERT(lo > 0, ("vm_reserv_break: lo is %d", lo));
|
|
/* Convert from ffsl() to ordinary bit numbering. */
|
|
lo--;
|
|
if (lo > 0) {
|
|
/* Redundantly clears bits < "hi". */
|
|
rv->popmap[i] &= ~((1UL << lo) - 1);
|
|
rv->popcnt -= lo - hi;
|
|
}
|
|
begin_zeroes = NBPOPMAP * i + lo;
|
|
/* Find the next 1 bit. */
|
|
do
|
|
hi = ffsl(rv->popmap[i]);
|
|
while (hi == 0 && ++i < NPOPMAP);
|
|
if (i != NPOPMAP)
|
|
/* Convert from ffsl() to ordinary bit numbering. */
|
|
hi--;
|
|
vm_phys_free_contig(&rv->pages[begin_zeroes], NBPOPMAP * i +
|
|
hi - begin_zeroes);
|
|
} while (i < NPOPMAP);
|
|
KASSERT(rv->popcnt == 0,
|
|
("vm_reserv_break: reserv %p's popcnt is corrupted", rv));
|
|
vm_reserv_broken++;
|
|
}
|
|
|
|
/*
|
|
* Breaks all reservations belonging to the given object.
|
|
*/
|
|
void
|
|
vm_reserv_break_all(vm_object_t object)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
mtx_lock(&vm_page_queue_free_mtx);
|
|
while ((rv = LIST_FIRST(&object->rvq)) != NULL) {
|
|
KASSERT(rv->object == object,
|
|
("vm_reserv_break_all: reserv %p is corrupted", rv));
|
|
if (rv->inpartpopq) {
|
|
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
|
|
rv->inpartpopq = FALSE;
|
|
}
|
|
vm_reserv_break(rv, NULL);
|
|
}
|
|
mtx_unlock(&vm_page_queue_free_mtx);
|
|
}
|
|
|
|
/*
|
|
* Frees the given page if it belongs to a reservation. Returns TRUE if the
|
|
* page is freed and FALSE otherwise.
|
|
*
|
|
* The free page queue lock must be held.
|
|
*/
|
|
boolean_t
|
|
vm_reserv_free_page(vm_page_t m)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
rv = vm_reserv_from_page(m);
|
|
if (rv->object == NULL)
|
|
return (FALSE);
|
|
vm_reserv_depopulate(rv, m - rv->pages);
|
|
return (TRUE);
|
|
}
|
|
|
|
/*
|
|
* Initializes the reservation management system. Specifically, initializes
|
|
* the reservation array.
|
|
*
|
|
* Requires that vm_page_array and first_page are initialized!
|
|
*/
|
|
void
|
|
vm_reserv_init(void)
|
|
{
|
|
vm_paddr_t paddr;
|
|
struct vm_phys_seg *seg;
|
|
int segind;
|
|
|
|
/*
|
|
* Initialize the reservation array. Specifically, initialize the
|
|
* "pages" field for every element that has an underlying superpage.
|
|
*/
|
|
for (segind = 0; segind < vm_phys_nsegs; segind++) {
|
|
seg = &vm_phys_segs[segind];
|
|
paddr = roundup2(seg->start, VM_LEVEL_0_SIZE);
|
|
while (paddr + VM_LEVEL_0_SIZE <= seg->end) {
|
|
vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT].pages =
|
|
PHYS_TO_VM_PAGE(paddr);
|
|
paddr += VM_LEVEL_0_SIZE;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns true if the given page belongs to a reservation and that page is
|
|
* free. Otherwise, returns false.
|
|
*/
|
|
bool
|
|
vm_reserv_is_page_free(vm_page_t m)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
rv = vm_reserv_from_page(m);
|
|
if (rv->object == NULL)
|
|
return (false);
|
|
return (popmap_is_clear(rv->popmap, m - rv->pages));
|
|
}
|
|
|
|
/*
|
|
* If the given page belongs to a reservation, returns the level of that
|
|
* reservation. Otherwise, returns -1.
|
|
*/
|
|
int
|
|
vm_reserv_level(vm_page_t m)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
rv = vm_reserv_from_page(m);
|
|
return (rv->object != NULL ? 0 : -1);
|
|
}
|
|
|
|
/*
|
|
* Returns a reservation level if the given page belongs to a fully-populated
|
|
* reservation and -1 otherwise.
|
|
*/
|
|
int
|
|
vm_reserv_level_iffullpop(vm_page_t m)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
rv = vm_reserv_from_page(m);
|
|
return (rv->popcnt == VM_LEVEL_0_NPAGES ? 0 : -1);
|
|
}
|
|
|
|
/*
|
|
* Prepare for the reactivation of a cached page.
|
|
*
|
|
* First, suppose that the given page "m" was allocated individually, i.e., not
|
|
* as part of a reservation, and cached. Then, suppose a reservation
|
|
* containing "m" is allocated by the same object. Although "m" and the
|
|
* reservation belong to the same object, "m"'s pindex may not match the
|
|
* reservation's.
|
|
*
|
|
* The free page queue must be locked.
|
|
*/
|
|
boolean_t
|
|
vm_reserv_reactivate_page(vm_page_t m)
|
|
{
|
|
vm_reserv_t rv;
|
|
int index;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
rv = vm_reserv_from_page(m);
|
|
if (rv->object == NULL)
|
|
return (FALSE);
|
|
KASSERT((m->flags & PG_CACHED) != 0,
|
|
("vm_reserv_reactivate_page: page %p is not cached", m));
|
|
if (m->object == rv->object &&
|
|
m->pindex - rv->pindex == (index = VM_RESERV_INDEX(m->object,
|
|
m->pindex)))
|
|
vm_reserv_populate(rv, index);
|
|
else {
|
|
KASSERT(rv->inpartpopq,
|
|
("vm_reserv_reactivate_page: reserv %p's inpartpopq is FALSE",
|
|
rv));
|
|
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
|
|
rv->inpartpopq = FALSE;
|
|
/* Don't release "m" to the physical memory allocator. */
|
|
vm_reserv_break(rv, m);
|
|
}
|
|
return (TRUE);
|
|
}
|
|
|
|
/*
|
|
* Breaks the given partially-populated reservation, releasing its cached and
|
|
* free pages to the physical memory allocator.
|
|
*
|
|
* The free page queue lock must be held.
|
|
*/
|
|
static void
|
|
vm_reserv_reclaim(vm_reserv_t rv)
|
|
{
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
KASSERT(rv->inpartpopq,
|
|
("vm_reserv_reclaim: reserv %p's inpartpopq is FALSE", rv));
|
|
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
|
|
rv->inpartpopq = FALSE;
|
|
vm_reserv_break(rv, NULL);
|
|
vm_reserv_reclaimed++;
|
|
}
|
|
|
|
/*
|
|
* Breaks the reservation at the head of the partially-populated reservation
|
|
* queue, releasing its cached and free pages to the physical memory
|
|
* allocator. Returns TRUE if a reservation is broken and FALSE otherwise.
|
|
*
|
|
* The free page queue lock must be held.
|
|
*/
|
|
boolean_t
|
|
vm_reserv_reclaim_inactive(void)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
if ((rv = TAILQ_FIRST(&vm_rvq_partpop)) != NULL) {
|
|
vm_reserv_reclaim(rv);
|
|
return (TRUE);
|
|
}
|
|
return (FALSE);
|
|
}
|
|
|
|
/*
|
|
* Searches the partially-populated reservation queue for the least recently
|
|
* active reservation with unused pages, i.e., cached or free, that satisfy the
|
|
* given request for contiguous physical memory. If a satisfactory reservation
|
|
* is found, it is broken. Returns TRUE if a reservation is broken and FALSE
|
|
* otherwise.
|
|
*
|
|
* The free page queue lock must be held.
|
|
*/
|
|
boolean_t
|
|
vm_reserv_reclaim_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
|
|
u_long alignment, vm_paddr_t boundary)
|
|
{
|
|
vm_paddr_t pa, size;
|
|
vm_reserv_t rv;
|
|
int hi, i, lo, low_index, next_free;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
if (npages > VM_LEVEL_0_NPAGES - 1)
|
|
return (FALSE);
|
|
size = npages << PAGE_SHIFT;
|
|
TAILQ_FOREACH(rv, &vm_rvq_partpop, partpopq) {
|
|
pa = VM_PAGE_TO_PHYS(&rv->pages[VM_LEVEL_0_NPAGES - 1]);
|
|
if (pa + PAGE_SIZE - size < low) {
|
|
/* This entire reservation is too low; go to next. */
|
|
continue;
|
|
}
|
|
pa = VM_PAGE_TO_PHYS(&rv->pages[0]);
|
|
if (pa + size > high) {
|
|
/* This entire reservation is too high; go to next. */
|
|
continue;
|
|
}
|
|
if (pa < low) {
|
|
/* Start the search for free pages at "low". */
|
|
low_index = (low + PAGE_MASK - pa) >> PAGE_SHIFT;
|
|
i = low_index / NBPOPMAP;
|
|
hi = low_index % NBPOPMAP;
|
|
} else
|
|
i = hi = 0;
|
|
do {
|
|
/* Find the next free page. */
|
|
lo = ffsl(~(((1UL << hi) - 1) | rv->popmap[i]));
|
|
while (lo == 0 && ++i < NPOPMAP)
|
|
lo = ffsl(~rv->popmap[i]);
|
|
if (i == NPOPMAP)
|
|
break;
|
|
/* Convert from ffsl() to ordinary bit numbering. */
|
|
lo--;
|
|
next_free = NBPOPMAP * i + lo;
|
|
pa = VM_PAGE_TO_PHYS(&rv->pages[next_free]);
|
|
KASSERT(pa >= low,
|
|
("vm_reserv_reclaim_contig: pa is too low"));
|
|
if (pa + size > high) {
|
|
/* The rest of this reservation is too high. */
|
|
break;
|
|
} else if ((pa & (alignment - 1)) != 0 ||
|
|
((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) {
|
|
/*
|
|
* The current page doesn't meet the alignment
|
|
* and/or boundary requirements. Continue
|
|
* searching this reservation until the rest
|
|
* of its free pages are either excluded or
|
|
* exhausted.
|
|
*/
|
|
hi = lo + 1;
|
|
if (hi >= NBPOPMAP) {
|
|
hi = 0;
|
|
i++;
|
|
}
|
|
continue;
|
|
}
|
|
/* Find the next used page. */
|
|
hi = ffsl(rv->popmap[i] & ~((1UL << lo) - 1));
|
|
while (hi == 0 && ++i < NPOPMAP) {
|
|
if ((NBPOPMAP * i - next_free) * PAGE_SIZE >=
|
|
size) {
|
|
vm_reserv_reclaim(rv);
|
|
return (TRUE);
|
|
}
|
|
hi = ffsl(rv->popmap[i]);
|
|
}
|
|
/* Convert from ffsl() to ordinary bit numbering. */
|
|
if (i != NPOPMAP)
|
|
hi--;
|
|
if ((NBPOPMAP * i + hi - next_free) * PAGE_SIZE >=
|
|
size) {
|
|
vm_reserv_reclaim(rv);
|
|
return (TRUE);
|
|
}
|
|
} while (i < NPOPMAP);
|
|
}
|
|
return (FALSE);
|
|
}
|
|
|
|
/*
|
|
* Transfers the reservation underlying the given page to a new object.
|
|
*
|
|
* The object must be locked.
|
|
*/
|
|
void
|
|
vm_reserv_rename(vm_page_t m, vm_object_t new_object, vm_object_t old_object,
|
|
vm_pindex_t old_object_offset)
|
|
{
|
|
vm_reserv_t rv;
|
|
|
|
VM_OBJECT_ASSERT_WLOCKED(new_object);
|
|
rv = vm_reserv_from_page(m);
|
|
if (rv->object == old_object) {
|
|
mtx_lock(&vm_page_queue_free_mtx);
|
|
if (rv->object == old_object) {
|
|
LIST_REMOVE(rv, objq);
|
|
LIST_INSERT_HEAD(&new_object->rvq, rv, objq);
|
|
rv->object = new_object;
|
|
rv->pindex -= old_object_offset;
|
|
}
|
|
mtx_unlock(&vm_page_queue_free_mtx);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns the size (in bytes) of a reservation of the specified level.
|
|
*/
|
|
int
|
|
vm_reserv_size(int level)
|
|
{
|
|
|
|
switch (level) {
|
|
case 0:
|
|
return (VM_LEVEL_0_SIZE);
|
|
case -1:
|
|
return (PAGE_SIZE);
|
|
default:
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocates the virtual and physical memory required by the reservation
|
|
* management system's data structures, in particular, the reservation array.
|
|
*/
|
|
vm_paddr_t
|
|
vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t high_water)
|
|
{
|
|
vm_paddr_t new_end;
|
|
size_t size;
|
|
|
|
/*
|
|
* Calculate the size (in bytes) of the reservation array. Round up
|
|
* from "high_water" because every small page is mapped to an element
|
|
* in the reservation array based on its physical address. Thus, the
|
|
* number of elements in the reservation array can be greater than the
|
|
* number of superpages.
|
|
*/
|
|
size = howmany(high_water, VM_LEVEL_0_SIZE) * sizeof(struct vm_reserv);
|
|
|
|
/*
|
|
* Allocate and map the physical memory for the reservation array. The
|
|
* next available virtual address is returned by reference.
|
|
*/
|
|
new_end = end - round_page(size);
|
|
vm_reserv_array = (void *)(uintptr_t)pmap_map(vaddr, new_end, end,
|
|
VM_PROT_READ | VM_PROT_WRITE);
|
|
bzero(vm_reserv_array, size);
|
|
|
|
/*
|
|
* Return the next available physical address.
|
|
*/
|
|
return (new_end);
|
|
}
|
|
|
|
#endif /* VM_NRESERVLEVEL > 0 */
|