--- /dev/null
+/*
+ * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License"). You may not use this file except in compliance with the
+ * License. Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ *
+ * This 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 OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * @APPLE_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 },
+ { NULL, NULL, 0, 0 }
+};
+
+typedef struct sched_average *sched_average_t;
+
+void
+compute_averages(void)
+{
+ register processor_set_t pset = &default_pset;
+ register int ncpus;
+ register int nthreads, nshared;
+ sched_average_t avg;
+ register uint32_t factor_now = 0;
+ register uint32_t average_now = 0;
+ register uint32_t load_now = 0;
+
+ if ((ncpus = pset->processor_count) > 0) {
+ /*
+ * Retrieve counts, ignoring
+ * the current thread.
+ */
+ nthreads = pset->run_count - 1;
+ nshared = pset->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;
+
+ pset->mach_factor = ((pset->mach_factor << 2) + factor_now) / 5;
+ pset->load_average = ((pset->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.
+ */
+ pset->pri_shift = sched_pri_shift - sched_load_shifts[load_now];
+ }
+ else {
+ pset->mach_factor = pset->load_average = 0;
+ pset->pri_shift = INT8_MAX;
+ nthreads = pset->run_count;
+ }
+
+ /*
+ * 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;
+ }
+ }
+}
projects / apple / xnu.git / blobdiff