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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2002 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 /* 31 * University Copyright- Copyright (c) 1982, 1986, 1988 32 * The Regents of the University of California 33 * All Rights Reserved 34 * 35 * University Acknowledgment- Portions of this document are derived from 36 * software developed by the University of California, Berkeley, and its 37 * contributors. 38 */ 39 40 #include <sys/types.h> 41 #include <sys/param.h> 42 #include <sys/sysmacros.h> 43 #include <sys/systm.h> 44 #include <sys/vmsystm.h> 45 #include <sys/cpuvar.h> 46 #include <sys/sysinfo.h> 47 48 /* 49 * This define represents the number of 50 * useful pages transferred per paging i/o operation, under the assumption 51 * that half of the total number is actually useful. However, if there's 52 * only one page transferred per operation, we assume that it's useful. 53 */ 54 55 #ifdef lint 56 #define UsefulPagesPerIO 1 57 #else /* lint */ 58 #define UsefulPagesPerIO nz((MAXBSIZE/PAGESIZE)/2) 59 #endif /* lint */ 60 61 extern int dopageout; 62 63 /* Average new into old with aging factor time */ 64 #define ave(smooth, cnt, time) \ 65 smooth = ((time - 1) * (smooth) + (cnt)) / (time) 66 67 /* 68 * pagein and pageout rates for use by swapper. 69 */ 70 ulong_t pginrate; /* 5 second average */ 71 ulong_t pgoutrate; /* 5 second average */ 72 73 static ulong_t ogpagein; /* pagein rate a sec ago */ 74 static ulong_t ogpageout; /* pageout rate a sec ago */ 75 76 /* 77 * Called once a second to gather statistics. 78 */ 79 void 80 vmmeter(void) 81 { 82 cpu_t *cp; 83 ulong_t gpagein, gpageout; 84 85 /* 86 * Compute 5 sec and 30 sec average free memory values. 87 */ 88 ave(avefree, freemem, 5); 89 ave(avefree30, freemem, 30); 90 91 /* 92 * Compute the 5 secs average of pageins and pageouts. 93 */ 94 gpagein = gpageout = 0; 95 96 cp = cpu_list; 97 do { 98 gpagein += (ulong_t)CPU_STATS(cp, vm.pgin); 99 gpageout += (ulong_t)CPU_STATS(cp, vm.pgout); 100 } while ((cp = cp->cpu_next) != cpu_list); 101 102 if ((gpagein >= ogpagein) && (gpageout >= ogpageout)) { 103 ave(pginrate, gpagein - ogpagein, 5); 104 ave(pgoutrate, gpageout - ogpageout, 5); 105 } 106 107 /* 108 * Save the current pagein/pageout values. 109 */ 110 ogpagein = gpagein; 111 ogpageout = gpageout; 112 113 if (!lotsfree || !dopageout) 114 return; 115 116 /* 117 * Decay deficit by the expected number of pages brought in since 118 * the last call (i.e., in the last second). The calculation 119 * assumes that one half of the pages brought in are actually 120 * useful (see comment above), and that half of the overall 121 * paging i/o activity is pageins as opposed to pageouts (the 122 * trailing factor of 2) It also assumes that paging i/o is done 123 * in units of MAXBSIZE bytes, which is a dubious assumption to 124 * apply to all file system types. 125 */ 126 deficit -= MIN(deficit, 127 MAX(deficit / 10, UsefulPagesPerIO * maxpgio / 2)); 128 } 129