/* * 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> #if CONFIG_TELEMETRY #include <kern/telemetry.h> #endif uint32_t avenrun[3] = {0, 0, 0}; uint32_t mach_factor[3] = {0, 0, 0}; #if defined(CONFIG_SCHED_TIMESHARE_CORE) /* * 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 #endif /* CONFIG_SCHED_TIMESHARE_CORE */ static unsigned int sched_nrun; typedef void (*sched_avg_comp_t)( void *param); static struct sched_average { sched_avg_comp_t comp; void *param; int period; /* in seconds */ uint64_t deadline; } sched_average[] = { { compute_averunnable, &sched_nrun, 5, 0 }, { compute_stack_target, NULL, 5, 1 }, { compute_memory_pressure, NULL, 1, 0 }, { compute_zone_gc_throttle, NULL, 60, 0 }, { compute_pageout_gc_throttle, NULL, 1, 0 }, { compute_pmap_gc_throttle, NULL, 60, 0 }, #if CONFIG_TELEMETRY { compute_telemetry, NULL, 1, 0 }, #endif { NULL, NULL, 0, 0 } }; typedef struct sched_average *sched_average_t; /* The "stdelta" parameter represents the number of scheduler maintenance * "ticks" that have elapsed since the last invocation, subject to * integer division imprecision. */ void compute_averages(uint64_t stdelta) { int ncpus, nthreads, nshared, nbackground, nshared_non_bg; uint32_t factor_now, average_now, load_now = 0, background_load_now = 0, combined_fgbg_load_now = 0; sched_average_t avg; uint64_t abstime, index; /* * Retrieve counts, ignoring * the current thread. */ ncpus = processor_avail_count; nthreads = sched_run_count - 1; nshared = sched_share_count; nbackground = sched_background_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; /* For those statistics that formerly relied on being recomputed * on timer ticks, advance by the approximate number of corresponding * elapsed intervals, thus compensating for potential idle intervals. */ for (index = 0; index < stdelta; index++) { 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. * Because our counters may be incremented and accessed * concurrently with respect to each other, we may have * windows where the invariant nthreads >= nshared >= nbackground * is broken, so truncate values in these cases. */ if (nshared > nthreads) nshared = nthreads; if (nbackground > nshared) nbackground = nshared; nshared_non_bg = nshared - nbackground; if (nshared_non_bg > ncpus) { if (ncpus > 1) load_now = nshared_non_bg / ncpus; else load_now = nshared_non_bg; if (load_now > NRQS - 1) load_now = NRQS - 1; } if (nbackground > ncpus) { if (ncpus > 1) background_load_now = nbackground / ncpus; else background_load_now = nbackground; if (background_load_now > NRQS - 1) background_load_now = NRQS - 1; } if (nshared > ncpus) { if (ncpus > 1) combined_fgbg_load_now = nshared / ncpus; else combined_fgbg_load_now = nshared; if (combined_fgbg_load_now > NRQS - 1) combined_fgbg_load_now = NRQS - 1; } /* * Sample total running threads. */ sched_nrun = nthreads; #if defined(CONFIG_SCHED_TIMESHARE_CORE) /* * 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]; sched_background_pri_shift = sched_fixed_shift - sched_load_shifts[background_load_now]; sched_combined_fgbg_pri_shift = sched_fixed_shift - sched_load_shifts[combined_fgbg_load_now]; /* * Compute old-style Mach load averages. */ for (index = 0; index < stdelta; index++) { 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; } } #endif /* CONFIG_SCHED_TIMESHARE_CORE */ /* * Compute averages in other components. */ abstime = mach_absolute_time(); for (avg = sched_average; avg->comp != NULL; ++avg) { if (abstime >= avg->deadline) { uint64_t period_abs = (avg->period * sched_one_second_interval); uint64_t ninvokes = 1; ninvokes += (abstime - avg->deadline) / period_abs; ninvokes = MIN(ninvokes, SCHED_TICK_MAX_DELTA); for (index = 0; index < ninvokes; index++) { (*avg->comp)(avg->param); } avg->deadline = abstime + period_abs; } } }