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Diffstat (limited to 'kern/mach_factor.c')
| -rw-r--r-- | kern/mach_factor.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/kern/mach_factor.c b/kern/mach_factor.c new file mode 100644 index 0000000..1a17213 --- /dev/null +++ b/kern/mach_factor.c @@ -0,0 +1,153 @@ +/* + * 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. + */ +/* + * File: kern/mach_factor.c + * Author: Avadis Tevanian, Jr. + * Date: 1986 + * + * Compute the Mach Factor. + */ + +#include <cpus.h> + +#include <mach/machine.h> +#include <mach/processor_info.h> +#include <kern/sched.h> +#include <kern/processor.h> +#include <kern/time_out.h> +#if MACH_KERNEL +#include <mach/kern_return.h> +#include <mach/port.h> +#endif MACH_KERNEL + + +long avenrun[3] = {0, 0, 0}; +long mach_factor[3] = {0, 0, 0}; + +/* + * Values are scaled by LOAD_SCALE, defined in processor_info.h + */ +static long fract[3] = { + 800, /* (4.0/5.0) 5 second average */ + 966, /* (29.0/30.0) 30 second average */ + 983, /* (59.0/60.) 1 minute average */ +}; + +void compute_mach_factor() +{ + register processor_set_t pset; + register processor_t processor; + register int ncpus; + register int nthreads; + register long factor_now; + register long average_now; + register long load_now; + + simple_lock(&all_psets_lock); + pset = (processor_set_t) queue_first(&all_psets); + while (!queue_end(&all_psets, (queue_entry_t)pset)) { + + /* + * If no processors, this pset is in suspended animation. + * No load calculations are performed. + */ + pset_lock(pset); + if((ncpus = pset->processor_count) > 0) { + + /* + * Count number of threads. + */ + nthreads = pset->runq.count; + processor = (processor_t) queue_first(&pset->processors); + while (!queue_end(&pset->processors, + (queue_entry_t)processor)) { + nthreads += processor->runq.count; + processor = + (processor_t) queue_next(&processor->processors); + } + + /* + * account for threads on cpus. + */ + nthreads += ncpus - pset->idle_count; + + /* + * The current thread (running this calculation) + * doesn't count; it's always in the default pset. + */ + if (pset == &default_pset) + nthreads -= 1; + + if (nthreads > ncpus) { + factor_now = (ncpus * LOAD_SCALE) / (nthreads + 1); + load_now = (nthreads << SCHED_SHIFT) / ncpus; + } + else { + factor_now = (ncpus - nthreads) * LOAD_SCALE; + load_now = SCHED_SCALE; + } + + /* + * Load average and mach factor calculations for + * those that ask about these things. + */ + + average_now = nthreads * LOAD_SCALE; + + pset->mach_factor = + ((pset->mach_factor << 2) + factor_now)/5; + pset->load_average = + ((pset->load_average << 2) + average_now)/5; + + /* + * And some ugly stuff to keep w happy. + */ + if (pset == &default_pset) { + 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; + } + } + + /* + * sched_load is the only thing used by scheduler. + * It is always at least 1 (i.e. SCHED_SCALE). + */ + pset->sched_load = (pset->sched_load + load_now) >> 1; + } + + pset_unlock(pset); + pset = (processor_set_t) queue_next(&pset->all_psets); + } + + simple_unlock(&all_psets_lock); +} |