/* * Copyright (c) 2000-2007 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ */ /* * Mach Operating System * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ /* */ /* * Author: Avadis Tevanian, Jr. * Date: 1986 * * Compute various averages. */ #include <mach/mach_types.h> #include <kern/sched.h> #include <kern/assert.h> #include <kern/processor.h> #include <kern/thread.h> uint32_t avenrun[3] = {0, 0, 0}; uint32_t mach_factor[3] = {0, 0, 0}; /* * Values are scaled by LOAD_SCALE, defined in processor_info.h */ #define base(n) ((n) << SCHED_TICK_SHIFT) #define frac(n) (((base(n) - 1) * LOAD_SCALE) / base(n)) static uint32_t fract[3] = { frac(5), /* 5 second average */ frac(30), /* 30 second average */ frac(60), /* 1 minute average */ }; #undef base #undef frac static unsigned int sched_nrun; typedef void (*sched_avg_comp_t)( void *param); #define SCHED_AVG_SECS(n) ((n) << SCHED_TICK_SHIFT) static struct sched_average { sched_avg_comp_t comp; void *param; int period; int tick; } sched_average[] = { { compute_averunnable, &sched_nrun, SCHED_AVG_SECS(5), 0 }, { compute_stack_target, NULL, SCHED_AVG_SECS(5), 1 }, { compute_memory_pressure, NULL, SCHED_AVG_SECS(1), 0 }, { NULL, NULL, 0, 0 } }; typedef struct sched_average *sched_average_t; void compute_averages(void) { int ncpus, nthreads, nshared; uint32_t factor_now, average_now, load_now = 0; sched_average_t avg; /* * Retrieve counts, ignoring * the current thread. */ ncpus = processor_avail_count; nthreads = sched_run_count - 1; nshared = sched_share_count; /* * Load average and mach factor calculations for * those which ask about these things. */ average_now = nthreads * LOAD_SCALE; if (nthreads > ncpus) factor_now = (ncpus * LOAD_SCALE) / (nthreads + 1); else factor_now = (ncpus - nthreads) * LOAD_SCALE; sched_mach_factor = ((sched_mach_factor << 2) + factor_now) / 5; sched_load_average = ((sched_load_average << 2) + average_now) / 5; /* * Compute the timeshare priority * conversion factor based on loading. */ if (nshared > nthreads) nshared = nthreads; if (nshared > ncpus) { if (ncpus > 1) load_now = nshared / ncpus; else load_now = nshared; if (load_now > NRQS - 1) load_now = NRQS - 1; } /* * The conversion factor consists of * two components: a fixed value based * on the absolute time unit, and a * dynamic portion based on loading. * * Zero loading results in a out of range * shift count. Accumulated usage is ignored * during conversion and new usage deltas * are discarded. */ sched_pri_shift = sched_fixed_shift - sched_load_shifts[load_now]; /* * Sample total running threads. */ sched_nrun = nthreads; /* * Compute old-style Mach load averages. */ { register int i; for (i = 0; i < 3; i++) { mach_factor[i] = ((mach_factor[i] * fract[i]) + (factor_now * (LOAD_SCALE - fract[i]))) / LOAD_SCALE; avenrun[i] = ((avenrun[i] * fract[i]) + (average_now * (LOAD_SCALE - fract[i]))) / LOAD_SCALE; } } /* * Compute averages in other components. */ for (avg = sched_average; avg->comp != NULL; ++avg) { if (++avg->tick >= avg->period) { (*avg->comp)(avg->param); avg->tick = 0; } } }