X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/91447636331957f3d9b5ca5b508f07c526b0074d..3903760236c30e3b5ace7a4eefac3a269d68957c:/osfmk/kern/sched_average.c diff --git a/osfmk/kern/sched_average.c b/osfmk/kern/sched_average.c index 61084906d..cf9520915 100644 --- a/osfmk/kern/sched_average.c +++ b/osfmk/kern/sched_average.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2007 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_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 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. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * 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 OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * 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_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ @@ -62,10 +68,18 @@ #include #include #include - +#if CONFIG_TELEMETRY +#include +#endif + +#include + uint32_t avenrun[3] = {0, 0, 0}; uint32_t mach_factor[3] = {0, 0, 0}; +uint32_t sched_load_average, sched_mach_factor; + +#if defined(CONFIG_SCHED_TIMESHARE_CORE) /* * Values are scaled by LOAD_SCALE, defined in processor_info.h */ @@ -81,107 +95,158 @@ static uint32_t fract[3] = { #undef base #undef frac +#endif /* CONFIG_SCHED_TIMESHARE_CORE */ + 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; + void *param; + int period; /* in seconds */ + uint64_t deadline; } sched_average[] = { - { compute_averunnable, &sched_nrun, SCHED_AVG_SECS(5), 0 }, - { compute_stack_target, NULL, SCHED_AVG_SECS(5), 1 }, + { compute_averunnable, &sched_nrun, 5, 0 }, + { compute_stack_target, NULL, 5, 1 }, + { compute_memory_pressure, NULL, 1, 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; +uint32_t load_now[TH_BUCKET_MAX]; + +/* 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(void) +compute_averages(uint64_t stdelta) { - 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) { + /* + * Retrieve a snapshot of the current run counts. + * + * Why not a bcopy()? Because we need atomic word-sized reads of sched_run_buckets, + * not byte-by-byte copy. + */ + uint32_t ncpus = processor_avail_count; + + load_now[TH_BUCKET_RUN] = sched_run_buckets[TH_BUCKET_RUN]; + load_now[TH_BUCKET_FIXPRI] = sched_run_buckets[TH_BUCKET_FIXPRI]; + load_now[TH_BUCKET_SHARE_FG] = sched_run_buckets[TH_BUCKET_SHARE_FG]; + load_now[TH_BUCKET_SHARE_UT] = sched_run_buckets[TH_BUCKET_SHARE_UT]; + load_now[TH_BUCKET_SHARE_BG] = sched_run_buckets[TH_BUCKET_SHARE_BG]; + + assert(load_now[TH_BUCKET_RUN] >= 0); + assert(load_now[TH_BUCKET_FIXPRI] >= 0); + + /* Ignore the current thread, which is a running fixpri thread */ + + uint32_t nthreads = load_now[TH_BUCKET_RUN] - 1; + uint32_t nfixpri = load_now[TH_BUCKET_FIXPRI] - 1; + + KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, + MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_LOAD) | DBG_FUNC_NONE, + load_now[TH_BUCKET_FIXPRI] - 1, load_now[TH_BUCKET_SHARE_FG], + load_now[TH_BUCKET_SHARE_BG], load_now[TH_BUCKET_SHARE_UT], 0); + + /* + * 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 - nfixpri) == (fg + bg + ut) + * is broken, so truncate values in these cases. + */ + + uint32_t timeshare_threads = (nthreads - nfixpri); + + for (uint32_t i = TH_BUCKET_SHARE_FG; i <= TH_BUCKET_SHARE_BG ; i++) { + if (load_now[i] > timeshare_threads) + load_now[i] = timeshare_threads; + } + + /* + * Utility threads contribute up to NCPUS of load to FG threads + */ + if (load_now[TH_BUCKET_SHARE_UT] <= ncpus) { + load_now[TH_BUCKET_SHARE_FG] += load_now[TH_BUCKET_SHARE_UT]; + } else { + load_now[TH_BUCKET_SHARE_FG] += ncpus; + } + + /* + * FG and UT should notice there's one thread of competition from BG, + * but no more. + */ + if (load_now[TH_BUCKET_SHARE_BG] > 0) { + load_now[TH_BUCKET_SHARE_FG] += 1; + load_now[TH_BUCKET_SHARE_UT] += 1; + } + + /* + * The conversion factor consists of two components: + * a fixed value based on the absolute time unit (sched_fixed_shift), + * and a dynamic portion based on load (sched_load_shifts). + * + * Zero load results in a out of range shift count. + */ + + for (uint32_t i = TH_BUCKET_SHARE_FG; i <= TH_BUCKET_SHARE_BG ; i++) { + uint32_t bucket_load = 0; + + if (load_now[i] > ncpus) { if (ncpus > 1) - load_now = nshared / ncpus; + bucket_load = load_now[i] / ncpus; else - load_now = nshared; + bucket_load = load_now[i]; - if (load_now > NRQS - 1) - load_now = NRQS - 1; + if (bucket_load > MAX_LOAD) + bucket_load = MAX_LOAD; } - /* - * 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; + sched_pri_shifts[i] = sched_fixed_shift - sched_load_shifts[bucket_load]; } /* - * Sample total running threads. + * Sample total running threads for the load average calculation. */ sched_nrun = nthreads; /* - * Compute old-style Mach load averages. + * Load average and mach factor calculations for + * those which ask about these things. + */ + uint32_t average_now = nthreads * LOAD_SCALE; + uint32_t factor_now; + + 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. */ - { - register int i; + for (uint32_t 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; + } - for (i = 0; i < 3; i++) { + /* + * Compute old-style Mach load averages. + */ + for (uint32_t index = 0; index < stdelta; index++) { + for (uint32_t i = 0; i < 3; i++) { mach_factor[i] = ((mach_factor[i] * fract[i]) + (factor_now * (LOAD_SCALE - fract[i]))) / LOAD_SCALE; @@ -191,12 +256,22 @@ compute_averages(void) } /* - * Compute averages in other components. + * 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; + uint64_t abstime = mach_absolute_time(); + + for (sched_average_t 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 (uint32_t index = 0; index < ninvokes; index++) { + (*avg->comp)(avg->param); + } + avg->deadline = abstime + period_abs; } } }