FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_object.c
1 /* $NetBSD: uvm_object.c,v 1.2 2006/10/12 10:13:35 yamt Exp $ */
2
3 /*
4 * Copyright (c) 2006 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the NetBSD
18 * Foundation, Inc. and its contributors.
19 * 4. Neither the name of The NetBSD Foundation nor the names of its
20 * contributors may be used to endorse or promote products derived
21 * from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 /*
37 * uvm_object.c: operate with memory objects
38 *
39 * TODO:
40 * 1. Support PG_RELEASED-using objects
41 *
42 */
43
44 #include <sys/cdefs.h>
45 __KERNEL_RCSID(0, "$NetBSD: uvm_object.c,v 1.2 2006/10/12 10:13:35 yamt Exp $");
46
47 #include "opt_uvmhist.h"
48
49 #include <sys/param.h>
50 #include <sys/lock.h>
51
52 #include <uvm/uvm.h>
53
54 /* We will fetch this page count per step */
55 #define FETCH_PAGECOUNT 16
56
57 /*
58 * uobj_wirepages: wire the pages of entire uobj
59 *
60 * => NOTE: this function should only be used for types of objects
61 * where PG_RELEASED flag is never set (aobj objects)
62 * => caller must pass page-aligned start and end values
63 */
64
65 int
66 uobj_wirepages(struct uvm_object *uobj, off_t start, off_t end)
67 {
68 int i, npages, error;
69 struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL;
70 off_t offset = start, left;
71
72 left = (end - start) >> PAGE_SHIFT;
73
74 simple_lock(&uobj->vmobjlock);
75 while (left) {
76
77 npages = MIN(FETCH_PAGECOUNT, left);
78
79 /* Get the pages */
80 memset(pgs, 0, sizeof(pgs));
81 error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0,
82 VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL,
83 PGO_ALLPAGES | PGO_SYNCIO);
84
85 if (error)
86 goto error;
87
88 simple_lock(&uobj->vmobjlock);
89 for (i = 0; i < npages; i++) {
90
91 KASSERT(pgs[i] != NULL);
92 KASSERT(!(pgs[i]->flags & PG_RELEASED));
93
94 /*
95 * Loan break
96 */
97 if (pgs[i]->loan_count) {
98 while (pgs[i]->loan_count) {
99 pg = uvm_loanbreak(pgs[i]);
100 if (!pg) {
101 simple_unlock(&uobj->vmobjlock);
102 uvm_wait("uobjwirepg");
103 simple_lock(&uobj->vmobjlock);
104 continue;
105 }
106 }
107 pgs[i] = pg;
108 }
109
110 if (pgs[i]->pqflags & PQ_AOBJ) {
111 pgs[i]->flags &= ~(PG_CLEAN);
112 uao_dropswap(uobj, i);
113 }
114 }
115
116 /* Wire the pages */
117 uvm_lock_pageq();
118 for (i = 0; i < npages; i++) {
119 uvm_pagewire(pgs[i]);
120 }
121 uvm_unlock_pageq();
122
123 /* Unbusy the pages */
124 uvm_page_unbusy(pgs, npages);
125
126 left -= npages;
127 offset += npages << PAGE_SHIFT;
128 }
129 simple_unlock(&uobj->vmobjlock);
130
131 return 0;
132
133 error:
134 /* Unwire the pages which has been wired */
135 uobj_unwirepages(uobj, start, offset);
136
137 return error;
138 }
139
140 /*
141 * uobj_unwirepages: unwire the pages of entire uobj
142 *
143 * => NOTE: this function should only be used for types of objects
144 * where PG_RELEASED flag is never set
145 * => caller must pass page-aligned start and end values
146 */
147
148 void
149 uobj_unwirepages(struct uvm_object *uobj, off_t start, off_t end)
150 {
151 struct vm_page *pg;
152 off_t offset;
153
154 simple_lock(&uobj->vmobjlock);
155 uvm_lock_pageq();
156 for (offset = start; offset < end; offset += PAGE_SIZE) {
157 pg = uvm_pagelookup(uobj, offset);
158
159 KASSERT(pg != NULL);
160 KASSERT(!(pg->flags & PG_RELEASED));
161
162 uvm_pageunwire(pg);
163 }
164 uvm_unlock_pageq();
165 simple_unlock(&uobj->vmobjlock);
166 }
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