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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /*
23: * @OSF_COPYRIGHT@
24: */
25: /*
26: * Mach Operating System
27: * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
28: * All Rights Reserved.
29: *
30: * Permission to use, copy, modify and distribute this software and its
31: * documentation is hereby granted, provided that both the copyright
32: * notice and this permission notice appear in all copies of the
33: * software, derivative works or modified versions, and any portions
34: * thereof, and that both notices appear in supporting documentation.
35: *
36: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
37: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
38: * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
39: *
40: * Carnegie Mellon requests users of this software to return to
41: *
42: * Software Distribution Coordinator or [email protected]
43: * School of Computer Science
44: * Carnegie Mellon University
45: * Pittsburgh PA 15213-3890
46: *
47: * any improvements or extensions that they make and grant Carnegie Mellon
48: * the rights to redistribute these changes.
49: */
50: /*
51: */
52: /*
53: * File: clock_prim.c
54: * Author: Avadis Tevanian, Jr.
55: * Date: 1986
56: *
57: * Clock primitives.
58: */
59:
60: #include <cpus.h>
61:
62: #include <mach/boolean.h>
63: #include <mach/kern_return.h>
64: #include <mach/machine.h>
65: #include <kern/host.h>
66: #include <kern/mach_param.h>
67: #include <kern/sched.h>
68: #include <kern/spl.h>
69: #include <kern/thread.h>
70: #include <kern/processor.h>
71: #include <machine/machparam.h>
72: #include <kern/sf.h>
73: #include <kern/mk_sp.h> /*** ??? fix so this can be removed ***/
74: /*** ??? Should this file be MK SP-specific? Or is it more general purpose? ***/
75:
76:
77:
78: /*
79: * USAGE_THRESHOLD is the amount by which usage must change to
80: * cause a priority shift that moves a thread between run queues.
81: */
82:
83: #ifdef PRI_SHIFT_2
84: #if PRI_SHIFT_2 > 0
85: #define USAGE_THRESHOLD (((1 << PRI_SHIFT) + (1 << PRI_SHIFT_2)) << (2 + SCHED_SHIFT))
86: #else /* PRI_SHIFT_2 > 0 */
87: #define USAGE_THRESHOLD (((1 << PRI_SHIFT) - (1 << -(PRI_SHIFT_2))) << (2 + SCHED_SHIFT))
88: #endif /* PRI_SHIFT_2 > 0 */
89: #else /* PRI_SHIFT_2 */
90: #define USAGE_THRESHOLD (1 << (PRI_SHIFT + 2 + SCHED_SHIFT))
91: #endif /* PRI_SHIFT_2 */
92:
93: /*
94: * thread_quantum_update:
95: *
96: * Recalculate the quantum and priority for a thread.
97: * The number of ticks that has elapsed since we were last called
98: * is passed as "nticks."
99: */
100:
101: void
102: thread_quantum_update(
103: register int mycpu,
104: register thread_t thread,
105: int nticks,
106: int state)
107: {
108: register int quantum;
109: register processor_t myprocessor;
110: #if NCPUS > 1
111: register processor_set_t pset;
112: #endif /* NCPUS > 1 */
113: spl_t s;
114:
115: myprocessor = cpu_to_processor(mycpu);
116: #if NCPUS > 1
117: pset = myprocessor->processor_set;
118: #endif /* NCPUS > 1 */
119:
120: /*
121: * Account for thread's utilization of these ticks.
122: * This assumes that there is *always* a current thread.
123: * When the processor is idle, it should be the idle thread.
124: */
125:
126: /*
127: * Update set_quantum and calculate the current quantum.
128: */
129: #if NCPUS > 1
130: pset->set_quantum = pset->machine_quantum[
131: (pset->runq.count > pset->processor_count) ?
132: pset->processor_count : pset->runq.count];
133:
134: if (myprocessor->runq.count != 0)
135: quantum = min_quantum;
136: else
137: quantum = pset->set_quantum;
138: #else /* NCPUS > 1 */
139: quantum = min_quantum;
140: default_pset.set_quantum = quantum;
141: #endif /* NCPUS > 1 */
142:
143: /*
144: * Now recompute the priority of the thread if appropriate.
145: */
146:
147: {
148: mk_sp_info_t sp_info;
149:
150: s = splsched();
151: thread_lock(thread);
152:
153: if (!(thread->policy & (POLICY_TIMESHARE|POLICY_RR|POLICY_FIFO))) {
154: thread_unlock(thread);
155: splx(s);
156: return;
157: }
158:
159: sp_info = (mk_sp_info_t)thread->sp_info;
160: assert(sp_info != SP_INFO_NULL);
161:
162: if (thread->policy == POLICY_FIFO) {
163: /* FIFO always has an infinite quantum */
164: myprocessor->first_quantum = TRUE;
165: /*** ??? fix me ***/
166: if (sp_info->sched_stamp != sched_tick)
167: update_priority(thread);
168: thread_unlock(thread);
169: splx(s);
170: ast_check();
171: return;
172: }
173:
174: myprocessor->quantum -= nticks;
175: #if NCPUS > 1
176: /*
177: * Runtime quantum adjustment. Use quantum_adj_index
178: * to avoid synchronizing quantum expirations.
179: */
180: if ( quantum != myprocessor->last_quantum &&
181: pset->processor_count > 1 ) {
182: myprocessor->last_quantum = quantum;
183: simple_lock(&pset->quantum_adj_lock);
184: quantum = min_quantum + (pset->quantum_adj_index *
185: (quantum - min_quantum)) /
186: (pset->processor_count - 1);
187: if (++(pset->quantum_adj_index) >= pset->processor_count)
188: pset->quantum_adj_index = 0;
189: simple_unlock(&pset->quantum_adj_lock);
190: }
191: #endif /* NCPUS > 1 */
192: if (myprocessor->quantum <= 0) {
193: /*** ??? fix me ***/
194: if (sp_info->sched_stamp != sched_tick) {
195: update_priority(thread);
196: }
197: else
198: if ( thread->policy == POLICY_TIMESHARE &&
199: /*** ??? fix me ***/
200: sp_info->depress_priority < 0 ) {
201: thread_timer_delta(thread);
202: /*** ??? fix me ***/
203: sp_info->sched_usage += thread->sched_delta;
204: thread->sched_delta = 0;
205: compute_my_priority(thread);
206: }
207:
208: /*
209: * This quantum is up, give this thread another.
210: */
211: myprocessor->first_quantum = FALSE;
212: if (thread->policy == POLICY_TIMESHARE)
213: myprocessor->quantum += quantum;
214: else {
215: /*
216: * RR policy has per-thread quantum.
217: *
218: */
219: /*** ??? fix me ***/
220: myprocessor->quantum += sp_info->sched_data;
221: }
222: }
223: /*
224: * Recompute priority if appropriate.
225: */
226: else {
227: /*** ??? fix me ***/
228: if (sp_info->sched_stamp != sched_tick) {
229: update_priority(thread);
230: }
231: else
232: if ( thread->policy == POLICY_TIMESHARE &&
233: /*** ??? fix me ***/
234: sp_info->depress_priority < 0 ) {
235: thread_timer_delta(thread);
236: if (thread->sched_delta >= USAGE_THRESHOLD) {
237: /*** ??? fix me ***/
238: sp_info->sched_usage += thread->sched_delta;
239: thread->sched_delta = 0;
240: compute_my_priority(thread);
241: }
242: }
243: }
244:
245: thread_unlock(thread);
246: splx(s);
247:
248: /*
249: * Check for and schedule ast if needed.
250: */
251: ast_check();
252: }
253: }
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