1/* 2 * Copyright (c) 2000-2007 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29 * @OSF_COPYRIGHT@ 30 */ 31/* 32 * Mach Operating System 33 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University 34 * All Rights Reserved. 35 * 36 * Permission to use, copy, modify and distribute this software and its 37 * documentation is hereby granted, provided that both the copyright 38 * notice and this permission notice appear in all copies of the 39 * software, derivative works or modified versions, and any portions 40 * thereof, and that both notices appear in supporting documentation. 41 * 42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 45 * 46 * Carnegie Mellon requests users of this software to return to 47 * 48 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 49 * School of Computer Science 50 * Carnegie Mellon University 51 * Pittsburgh PA 15213-3890 52 * 53 * any improvements or extensions that they make and grant Carnegie Mellon 54 * the rights to redistribute these changes. 55 */ 56/* 57 */ 58/* 59 * Author: Avadis Tevanian, Jr. 60 * Date: 1986 61 * 62 * Compute various averages. 63 */ 64 65#include <mach/mach_types.h> 66 67#include <kern/sched.h> 68#include <kern/assert.h> 69#include <kern/processor.h> 70#include <kern/thread.h> 71 72uint32_t avenrun[3] = {0, 0, 0}; 73uint32_t mach_factor[3] = {0, 0, 0}; 74 75#if defined(CONFIG_SCHED_TRADITIONAL) 76/* 77 * Values are scaled by LOAD_SCALE, defined in processor_info.h 78 */ 79#define base(n) ((n) << SCHED_TICK_SHIFT) 80#define frac(n) (((base(n) - 1) * LOAD_SCALE) / base(n)) 81 82static uint32_t fract[3] = { 83 frac(5), /* 5 second average */ 84 frac(30), /* 30 second average */ 85 frac(60), /* 1 minute average */ 86}; 87 88#undef base 89#undef frac 90 91#endif /* CONFIG_SCHED_TRADITIONAL */ 92 93static unsigned int sched_nrun; 94 95typedef void (*sched_avg_comp_t)( 96 void *param); 97 98static struct sched_average { 99 sched_avg_comp_t comp; 100 void *param; 101 int period; /* in seconds */ 102 uint64_t deadline; 103} sched_average[] = { 104 { compute_averunnable, &sched_nrun, 5, 0 }, 105 { compute_stack_target, NULL, 5, 1 }, 106 { compute_memory_pressure, NULL, 1, 0 }, 107 { compute_zone_gc_throttle, NULL, 60, 0 }, 108 { compute_pageout_gc_throttle, NULL, 1, 0 }, 109 { compute_pmap_gc_throttle, NULL, 60, 0 }, 110 { NULL, NULL, 0, 0 } 111}; 112 113typedef struct sched_average *sched_average_t; 114 115void 116compute_averages(void) 117{ 118 int ncpus, nthreads, nshared; 119 uint32_t factor_now, average_now, load_now = 0; 120 sched_average_t avg; 121 uint64_t abstime; 122 123 /* 124 * Retrieve counts, ignoring 125 * the current thread. 126 */ 127 ncpus = processor_avail_count; 128 nthreads = sched_run_count - 1; 129 nshared = sched_share_count; 130 131 /* 132 * Load average and mach factor calculations for 133 * those which ask about these things. 134 */ 135 average_now = nthreads * LOAD_SCALE; 136 137 if (nthreads > ncpus) 138 factor_now = (ncpus * LOAD_SCALE) / (nthreads + 1); 139 else 140 factor_now = (ncpus - nthreads) * LOAD_SCALE; 141 142 sched_mach_factor = ((sched_mach_factor << 2) + factor_now) / 5; 143 sched_load_average = ((sched_load_average << 2) + average_now) / 5; 144 145 /* 146 * Compute the timeshare priority 147 * conversion factor based on loading. 148 */ 149 if (nshared > nthreads) 150 nshared = nthreads; 151 152 if (nshared > ncpus) { 153 if (ncpus > 1) 154 load_now = nshared / ncpus; 155 else 156 load_now = nshared; 157 158 if (load_now > NRQS - 1) 159 load_now = NRQS - 1; 160 } 161 162 /* 163 * Sample total running threads. 164 */ 165 sched_nrun = nthreads; 166 167#if defined(CONFIG_SCHED_TRADITIONAL) 168 169 /* 170 * The conversion factor consists of 171 * two components: a fixed value based 172 * on the absolute time unit, and a 173 * dynamic portion based on loading. 174 * 175 * Zero loading results in a out of range 176 * shift count. Accumulated usage is ignored 177 * during conversion and new usage deltas 178 * are discarded. 179 */ 180 sched_pri_shift = sched_fixed_shift - sched_load_shifts[load_now]; 181 182 /* 183 * Compute old-style Mach load averages. 184 */ 185 { 186 register int i; 187 188 for (i = 0; i < 3; i++) { 189 mach_factor[i] = ((mach_factor[i] * fract[i]) + 190 (factor_now * (LOAD_SCALE - fract[i]))) / LOAD_SCALE; 191 192 avenrun[i] = ((avenrun[i] * fract[i]) + 193 (average_now * (LOAD_SCALE - fract[i]))) / LOAD_SCALE; 194 } 195 } 196#endif /* CONFIG_SCHED_TRADITIONAL */ 197 198 /* 199 * Compute averages in other components. 200 */ 201 abstime = mach_absolute_time(); 202 for (avg = sched_average; avg->comp != NULL; ++avg) { 203 if (abstime >= avg->deadline) { 204 (*avg->comp)(avg->param); 205 avg->deadline = abstime + avg->period * sched_one_second_interval; 206 } 207 } 208} 209