67b7e4345e
case that the reservation contained "low", the starting position in the popmap for the free page search was incorrectly calculated. The most likely (and visible) symptom of this error was the assertion failure, "vm_reserv_reclaim_contig: pa is too low".
1113 lines
33 KiB
C
1113 lines
33 KiB
C
/*-
|
|
* 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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/*
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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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|
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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;
|
|
struct vm_phys_seg *seg;
|
|
vm_reserv_t rv;
|
|
int fullpop, segind;
|
|
|
|
fullpop = 0;
|
|
for (segind = 0; segind < vm_phys_nsegs; segind++) {
|
|
seg = &vm_phys_segs[segind];
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|
paddr = roundup2(seg->start, VM_LEVEL_0_SIZE);
|
|
while (paddr + VM_LEVEL_0_SIZE <= seg->end) {
|
|
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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|
}
|
|
|
|
/*
|
|
* Describes the current state of the partially-populated reservation queue.
|
|
*/
|
|
static int
|
|
sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct sbuf sbuf;
|
|
vm_reserv_t rv;
|
|
int counter, error, level, unused_pages;
|
|
|
|
error = sysctl_wire_old_buffer(req, 0);
|
|
if (error != 0)
|
|
return (error);
|
|
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
|
|
sbuf_printf(&sbuf, "\nLEVEL SIZE NUMBER\n\n");
|
|
for (level = -1; level <= VM_NRESERVLEVEL - 2; level++) {
|
|
counter = 0;
|
|
unused_pages = 0;
|
|
mtx_lock(&vm_page_queue_free_mtx);
|
|
TAILQ_FOREACH(rv, &vm_rvq_partpop/*[level]*/, partpopq) {
|
|
counter++;
|
|
unused_pages += VM_LEVEL_0_NPAGES - rv->popcnt;
|
|
}
|
|
mtx_unlock(&vm_page_queue_free_mtx);
|
|
sbuf_printf(&sbuf, "%5d: %6dK, %6d\n", level,
|
|
unused_pages * ((int)PAGE_SIZE / 1024), counter);
|
|
}
|
|
error = sbuf_finish(&sbuf);
|
|
sbuf_delete(&sbuf);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Reduces the given reservation's population count. If the population count
|
|
* becomes zero, the reservation is destroyed. Additionally, moves the
|
|
* reservation to the tail of the partially-populated reservation queue if the
|
|
* population count is non-zero.
|
|
*
|
|
* The free page queue lock must be held.
|
|
*/
|
|
static void
|
|
vm_reserv_depopulate(vm_reserv_t rv, int index)
|
|
{
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
KASSERT(rv->object != NULL,
|
|
("vm_reserv_depopulate: reserv %p is free", rv));
|
|
KASSERT(popmap_is_set(rv->popmap, index),
|
|
("vm_reserv_depopulate: reserv %p's popmap[%d] is clear", rv,
|
|
index));
|
|
KASSERT(rv->popcnt > 0,
|
|
("vm_reserv_depopulate: reserv %p's popcnt is corrupted", rv));
|
|
if (rv->inpartpopq) {
|
|
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
|
|
rv->inpartpopq = FALSE;
|
|
} else {
|
|
KASSERT(rv->pages->psind == 1,
|
|
("vm_reserv_depopulate: reserv %p is already demoted",
|
|
rv));
|
|
rv->pages->psind = 0;
|
|
}
|
|
popmap_clear(rv->popmap, index);
|
|
rv->popcnt--;
|
|
if (rv->popcnt == 0) {
|
|
LIST_REMOVE(rv, objq);
|
|
rv->object = NULL;
|
|
vm_phys_free_pages(rv->pages, VM_LEVEL_0_ORDER);
|
|
vm_reserv_freed++;
|
|
} else {
|
|
rv->inpartpopq = TRUE;
|
|
TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns the reservation to which the given page might belong.
|
|
*/
|
|
static __inline vm_reserv_t
|
|
vm_reserv_from_page(vm_page_t m)
|
|
{
|
|
|
|
return (&vm_reserv_array[VM_PAGE_TO_PHYS(m) >> VM_LEVEL_0_SHIFT]);
|
|
}
|
|
|
|
/*
|
|
* Returns TRUE if the given reservation contains the given page index and
|
|
* FALSE otherwise.
|
|
*/
|
|
static __inline boolean_t
|
|
vm_reserv_has_pindex(vm_reserv_t rv, vm_pindex_t pindex)
|
|
{
|
|
|
|
return (((pindex - rv->pindex) & ~(VM_LEVEL_0_NPAGES - 1)) == 0);
|
|
}
|
|
|
|
/*
|
|
* Increases the given reservation's population count. Moves the reservation
|
|
* to the tail of the partially-populated reservation queue.
|
|
*
|
|
* The free page queue must be locked.
|
|
*/
|
|
static void
|
|
vm_reserv_populate(vm_reserv_t rv, int index)
|
|
{
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
KASSERT(rv->object != NULL,
|
|
("vm_reserv_populate: reserv %p is free", rv));
|
|
KASSERT(popmap_is_clear(rv->popmap, index),
|
|
("vm_reserv_populate: reserv %p's popmap[%d] is set", rv,
|
|
index));
|
|
KASSERT(rv->popcnt < VM_LEVEL_0_NPAGES,
|
|
("vm_reserv_populate: reserv %p is already full", rv));
|
|
KASSERT(rv->pages->psind == 0,
|
|
("vm_reserv_populate: reserv %p is already promoted", rv));
|
|
if (rv->inpartpopq) {
|
|
TAILQ_REMOVE(&vm_rvq_partpop, rv, partpopq);
|
|
rv->inpartpopq = FALSE;
|
|
}
|
|
popmap_set(rv->popmap, index);
|
|
rv->popcnt++;
|
|
if (rv->popcnt < VM_LEVEL_0_NPAGES) {
|
|
rv->inpartpopq = TRUE;
|
|
TAILQ_INSERT_TAIL(&vm_rvq_partpop, rv, partpopq);
|
|
} else
|
|
rv->pages->psind = 1;
|
|
}
|
|
|
|
/*
|
|
* Allocates a contiguous set of physical pages of the given size "npages"
|
|
* from existing or newly created reservations. All of the physical pages
|
|
* must be at or above the given physical address "low" and below the given
|
|
* physical address "high". The given value "alignment" determines the
|
|
* alignment of the first physical page in the set. If the given value
|
|
* "boundary" is non-zero, then the set of physical pages cannot cross any
|
|
* physical address boundary that is a multiple of that value. Both
|
|
* "alignment" and "boundary" must be a power of two.
|
|
*
|
|
* The object and free page queue must be locked.
|
|
*/
|
|
vm_page_t
|
|
vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages,
|
|
vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
|
|
{
|
|
vm_paddr_t pa, size;
|
|
vm_page_t m, m_ret, mpred, msucc;
|
|
vm_pindex_t first, leftcap, rightcap;
|
|
vm_reserv_t rv;
|
|
u_long allocpages, maxpages, minpages;
|
|
int i, index, n;
|
|
|
|
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
|
|
VM_OBJECT_ASSERT_WLOCKED(object);
|
|
KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0"));
|
|
|
|
/*
|
|
* Is a reservation fundamentally impossible?
|
|
*/
|
|
if (pindex < VM_RESERV_INDEX(object, pindex) ||
|
|
pindex + npages > object->size)
|
|
return (NULL);
|
|
|
|
/*
|
|
* All reservations of a particular size have the same alignment.
|
|
* Assuming that the first page is allocated from a reservation, the
|
|
* least significant bits of its physical address can be determined
|
|
* from its offset from the beginning of the reservation and the size
|
|
* of the reservation.
|
|
*
|
|
* Could the specified index within a reservation of the smallest
|
|
* possible size satisfy the alignment and boundary requirements?
|
|
*/
|
|
pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT;
|
|
if ((pa & (alignment - 1)) != 0)
|
|
return (NULL);
|
|
size = npages << PAGE_SHIFT;
|
|
if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0)
|
|
return (NULL);
|
|
|
|
/*
|
|
* Look for an existing reservation.
|
|
*/
|
|
mpred = vm_radix_lookup_le(&object->rtree, pindex);
|
|
if (mpred != NULL) {
|
|
KASSERT(mpred->pindex < pindex,
|
|
("vm_reserv_alloc_contig: pindex already allocated"));
|
|
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_contig: pindex already allocated"));
|
|
rv = vm_reserv_from_page(msucc);
|
|
if (rv->object == object && vm_reserv_has_pindex(rv, pindex))
|
|
goto found;
|
|
}
|
|
|
|
/*
|
|
* Could at least one reservation fit between the first index to the
|
|
* left that can be used ("leftcap") and the first index to the right
|
|
* that cannot be used ("rightcap")?
|
|
*/
|
|
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);
|
|
}
|
|
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 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 */
|