xref: /illumos-gate/usr/src/uts/common/vm/vm_rm.c (revision 0d5ae8c1)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 #include <sys/types.h>
40 #include <sys/t_lock.h>
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/mman.h>
44 #include <sys/sysmacros.h>
45 #include <sys/errno.h>
46 #include <sys/signal.h>
47 #include <sys/user.h>
48 #include <sys/proc.h>
49 #include <sys/cmn_err.h>
50 #include <sys/debug.h>
51 
52 #include <vm/hat.h>
53 #include <vm/as.h>
54 #include <vm/seg_vn.h>
55 #include <vm/rm.h>
56 #include <vm/seg.h>
57 #include <vm/page.h>
58 
59 /*
60  * Yield the memory claim requirement for an address space.
61  *
62  * This is currently implemented as the number of active hardware
63  * translations that have page structures.  Therefore, it can
64  * underestimate the traditional resident set size, eg, if the
65  * physical page is present and the hardware translation is missing;
66  * and it can overestimate the rss, eg, if there are active
67  * translations to a frame buffer with page structs.
68  * Also, it does not take sharing into account.
69  */
70 size_t
rm_asrss(as)71 rm_asrss(as)
72 	register struct as *as;
73 {
74 	if (as != (struct as *)NULL && as != &kas)
75 		return ((size_t)btop(hat_get_mapped_size(as->a_hat)));
76 	else
77 		return (0);
78 }
79 
80 /*
81  * Return a 16-bit binary fraction representing the percent of total memory
82  * used by this address space.  Binary point is to right of high-order bit.
83  * Defined as the ratio of a_rss for the process to total physical memory.
84  * This assumes 2s-complement arithmetic and that shorts and longs are
85  * 16 bits and 32 bits, respectively.
86  */
87 ushort_t
rm_pctmemory(struct as * as)88 rm_pctmemory(struct as *as)
89 {
90 	/* This can't overflow */
91 	ulong_t num = (ulong_t)rm_asrss(as) << (PAGESHIFT-1);
92 	int shift = 16 - PAGESHIFT;
93 	ulong_t total = total_pages;
94 
95 	if (shift < 0) {
96 		num >>= (-shift);
97 		shift = 0;
98 	}
99 	while (shift > 0 && (num & 0x80000000) == 0) {
100 		shift--;
101 		num <<= 1;
102 	}
103 	if (shift > 0)
104 		total >>= shift;
105 
106 	return (num / total);
107 }
108