[apple/xnu.git] / osfmk / kern / priority.c

/*
 * Copyright (c) 2000-2004 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.
 */
/*
 */
/*
 *	File:	clock_prim.c
 *	Author:	Avadis Tevanian, Jr.
 *	Date:	1986
 *
 *	Clock primitives.
 */

#include <mach/boolean.h>
#include <mach/kern_return.h>
#include <mach/machine.h>
#include <kern/host.h>
#include <kern/mach_param.h>
#include <kern/sched.h>
#include <kern/spl.h>
#include <kern/thread.h>
#include <kern/processor.h>
#include <machine/machparam.h>

/*
 *	thread_quantum_expire:
 *
 *	Recalculate the quantum and priority for a thread.
 */

void
thread_quantum_expire(
	timer_call_param_t	p0,
	timer_call_param_t	p1)
{
	register processor_t		myprocessor = p0;
	register thread_t			thread = p1;
	spl_t						s;

	s = splsched();
	thread_lock(thread);

	/*
	 *	Check for fail-safe trip.
	 */
	if (!(thread->sched_mode & TH_MODE_TIMESHARE)) {
		uint64_t			new_computation;

		new_computation = myprocessor->quantum_end;
		new_computation -= thread->computation_epoch;
		if (new_computation + thread->computation_metered >
											max_unsafe_computation) {

			if (thread->sched_mode & TH_MODE_REALTIME) {
				thread->priority = DEPRESSPRI;

				thread->safe_mode |= TH_MODE_REALTIME;
				thread->sched_mode &= ~TH_MODE_REALTIME;
			}

			pset_share_incr(thread->processor_set);

			thread->safe_release = sched_tick + sched_safe_duration;
			thread->sched_mode |= (TH_MODE_FAILSAFE|TH_MODE_TIMESHARE);
			thread->sched_mode &= ~TH_MODE_PREEMPT;
		}
	}
		
	/*
	 *	Recompute scheduled priority if appropriate.
	 */
	if (thread->sched_stamp != sched_tick)
		update_priority(thread);
	else
	if (thread->sched_mode & TH_MODE_TIMESHARE) {
		register uint32_t	delta;

		thread_timer_delta(thread, delta);

		/*
		 *	Accumulate timesharing usage only
		 *	during contention for processor
		 *	resources.
		 */
		if (thread->pri_shift < INT8_MAX)
			thread->sched_usage += delta;

		thread->cpu_delta += delta;

		/*
		 * Adjust the scheduled priority if
		 * the thread has not been promoted
		 * and is not depressed.
		 */
		if (	!(thread->sched_mode & TH_MODE_PROMOTED)	&&
				!(thread->sched_mode & TH_MODE_ISDEPRESSED)		)
			compute_my_priority(thread);
	}

	/*
	 *	This quantum is up, give this thread another.
	 */
	if (first_timeslice(myprocessor))
		myprocessor->timeslice--;

	thread_quantum_init(thread);
	myprocessor->quantum_end += thread->current_quantum;
	timer_call_enter1(&myprocessor->quantum_timer,
							thread, myprocessor->quantum_end);

	thread_unlock(thread);

	/*
	 * Check for and schedule ast if needed.
	 */
	ast_check(myprocessor);

	splx(s);
}

/*
 *	Define shifts for simulating (5/8) ** n
 *
 *	Shift structures for holding update shifts.  Actual computation
 *	is  usage = (usage >> shift1) +/- (usage >> abs(shift2))  where the
 *	+/- is determined by the sign of shift 2.
 */
struct shift_data {
	int	shift1;
	int	shift2;
};

#define SCHED_DECAY_TICKS	32
static struct shift_data	sched_decay_shifts[SCHED_DECAY_TICKS] = {
	{1,1},{1,3},{1,-3},{2,-7},{3,5},{3,-5},{4,-8},{5,7},
	{5,-7},{6,-10},{7,10},{7,-9},{8,-11},{9,12},{9,-11},{10,-13},
	{11,14},{11,-13},{12,-15},{13,17},{13,-15},{14,-17},{15,19},{16,18},
	{16,-19},{17,22},{18,20},{18,-20},{19,26},{20,22},{20,-22},{21,-27}
};

/*
 *	do_priority_computation:
 *
 *	Calculate the timesharing priority based upon usage and load.
 */
#define do_priority_computation(thread, pri)							\
	MACRO_BEGIN															\
	(pri) = (thread)->priority		/* start with base priority */		\
	    - ((thread)->sched_usage >> (thread)->pri_shift);				\
	if ((pri) < MINPRI_USER)											\
		(pri) = MINPRI_USER;											\
	else																\
	if ((pri) > MAXPRI_KERNEL)											\
		(pri) = MAXPRI_KERNEL;											\
	MACRO_END

/*
 *	set_priority:
 *
 *	Set the base priority of the thread
 *	and reset its scheduled priority.
 *
 *	Called with the thread locked.
 */
void
set_priority(
	register thread_t	thread,
	register int		priority)
{
	thread->priority = priority;
	compute_priority(thread, FALSE);
}

/*
 *	compute_priority:
 *
 *	Reset the scheduled priority of the thread
 *	according to its base priority if the
 *	thread has not been promoted or depressed.
 *
 *	Called with the thread locked.
 */
void
compute_priority(
	register thread_t	thread,
	boolean_t			override_depress)
{
	register int		priority;

	if (	!(thread->sched_mode & TH_MODE_PROMOTED)			&&
			(!(thread->sched_mode & TH_MODE_ISDEPRESSED)	||
				 override_depress							)		) {
		if (thread->sched_mode & TH_MODE_TIMESHARE)
			do_priority_computation(thread, priority);
		else
			priority = thread->priority;

		set_sched_pri(thread, priority);
	}
}

/*
 *	compute_my_priority:
 *
 *	Reset the scheduled priority for
 *	a timesharing thread.
 *
 *	Only for use on the current thread
 *	if timesharing and not depressed.
 *
 *	Called with the thread locked.
 */
void
compute_my_priority(
	register thread_t	thread)
{
	register int		priority;

	do_priority_computation(thread, priority);
	assert(thread->runq == RUN_QUEUE_NULL);
	thread->sched_pri = priority;
}

/*
 *	update_priority
 *
 *	Perform housekeeping operations driven by scheduler tick.
 *
 *	Called with the thread locked.
 */
void
update_priority(
	register thread_t	thread)
{
	register unsigned	ticks;
	register uint32_t	delta;

	ticks = sched_tick - thread->sched_stamp;
	assert(ticks != 0);
	thread->sched_stamp += ticks;
	thread->pri_shift = thread->processor_set->pri_shift;

	/*
	 *	Gather cpu usage data.
	 */
	thread_timer_delta(thread, delta);
	if (ticks < SCHED_DECAY_TICKS) {
		register struct shift_data	*shiftp;

		/*
		 *	Accumulate timesharing usage only
		 *	during contention for processor
		 *	resources.
		 */
		if (thread->pri_shift < INT8_MAX)
			thread->sched_usage += delta;

		thread->cpu_usage += delta + thread->cpu_delta;
		thread->cpu_delta = 0;

		shiftp = &sched_decay_shifts[ticks];
		if (shiftp->shift2 > 0) {
		    thread->cpu_usage =
						(thread->cpu_usage >> shiftp->shift1) +
						(thread->cpu_usage >> shiftp->shift2);
		    thread->sched_usage =
						(thread->sched_usage >> shiftp->shift1) +
						(thread->sched_usage >> shiftp->shift2);
		}
		else {
		    thread->cpu_usage =
						(thread->cpu_usage >> shiftp->shift1) -
						(thread->cpu_usage >> -(shiftp->shift2));
		    thread->sched_usage =
						(thread->sched_usage >> shiftp->shift1) -
						(thread->sched_usage >> -(shiftp->shift2));
		}
	}
	else {
		thread->cpu_usage = thread->cpu_delta = 0;
		thread->sched_usage = 0;
	}

	/*
	 *	Check for fail-safe release.
	 */
	if (	(thread->sched_mode & TH_MODE_FAILSAFE)		&&
			thread->sched_stamp >= thread->safe_release		) {
		if (!(thread->safe_mode & TH_MODE_TIMESHARE)) {
			if (thread->safe_mode & TH_MODE_REALTIME) {
				thread->priority = BASEPRI_RTQUEUES;

				thread->sched_mode |= TH_MODE_REALTIME;
			}

			thread->sched_mode &= ~TH_MODE_TIMESHARE;

			if (thread->state & TH_RUN)
				pset_share_decr(thread->processor_set);

			if (!(thread->sched_mode & TH_MODE_ISDEPRESSED))
				set_sched_pri(thread, thread->priority);
		}

		thread->safe_mode = 0;
		thread->sched_mode &= ~TH_MODE_FAILSAFE;
	}

	/*
	 *	Recompute scheduled priority if appropriate.
	 */
	if (	(thread->sched_mode & TH_MODE_TIMESHARE)	&&
			!(thread->sched_mode & TH_MODE_PROMOTED)	&&
			!(thread->sched_mode & TH_MODE_ISDEPRESSED)		) {
		register int		new_pri;

		do_priority_computation(thread, new_pri);
		if (new_pri != thread->sched_pri) {
			run_queue_t		runq;

			runq = run_queue_remove(thread);
			thread->sched_pri = new_pri;
			if (runq != RUN_QUEUE_NULL)
				thread_setrun(thread, SCHED_TAILQ);
		}
	}
}
Commit	Line	Data
1c79356b	1	/*
91447636	2	* Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
1c79356b	3	*
8f6c56a5	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
8f6c56a5 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
8ad349bb	24	* limitations under the License.
8f6c56a5 A	25	*
8f6c56a5 A	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* @OSF_COPYRIGHT@
	30	*/
	31	/*
	32	* Mach Operating System
	33	* Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
	34	* All Rights Reserved.
	35	*
	36	* Permission to use, copy, modify and distribute this software and its
	37	* documentation is hereby granted, provided that both the copyright
	38	* notice and this permission notice appear in all copies of the
	39	* software, derivative works or modified versions, and any portions
	40	* thereof, and that both notices appear in supporting documentation.
	41	*
	42	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	43	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	44	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	45	*
	46	* Carnegie Mellon requests users of this software to return to
	47	*
	48	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	49	* School of Computer Science
	50	* Carnegie Mellon University
	51	* Pittsburgh PA 15213-3890
	52	*
	53	* any improvements or extensions that they make and grant Carnegie Mellon
	54	* the rights to redistribute these changes.
	55	*/
	56	/*
	57	*/
	58	/*
	59	* File: clock_prim.c
	60	* Author: Avadis Tevanian, Jr.
	61	* Date: 1986
	62	*
	63	* Clock primitives.
	64	*/
	65
1c79356b A	66	#include <mach/boolean.h>
	67	#include <mach/kern_return.h>
	68	#include <mach/machine.h>
	69	#include <kern/host.h>
	70	#include <kern/mach_param.h>
	71	#include <kern/sched.h>
	72	#include <kern/spl.h>
	73	#include <kern/thread.h>
	74	#include <kern/processor.h>
	75	#include <machine/machparam.h>
1c79356b A	76
1c79356b A	77	/*
0b4e3aa0	78	* thread_quantum_expire:
1c79356b A	79	*
1c79356b A	80	* Recalculate the quantum and priority for a thread.
1c79356b A	81	*/
	82
	83	void
0b4e3aa0 A	84	thread_quantum_expire(
	85	timer_call_param_t p0,
	86	timer_call_param_t p1)
1c79356b	87	{
0b4e3aa0 A	88	register processor_t myprocessor = p0;
0b4e3aa0 A	89	register thread_t thread = p1;
1c79356b A	90	spl_t s;
1c79356b A	91
0b4e3aa0 A	92	s = splsched();
0b4e3aa0 A	93	thread_lock(thread);
1c79356b A	94
1c79356b A	95	/*
9bccf70c	96	* Check for fail-safe trip.
1c79356b	97	*/
0b4e3aa0	98	if (!(thread->sched_mode & TH_MODE_TIMESHARE)) {
0b4e3aa0 A	99	uint64_t new_computation;
	100
	101	new_computation = myprocessor->quantum_end;
	102	new_computation -= thread->computation_epoch;
9bccf70c	103	if (new_computation + thread->computation_metered >
0b4e3aa0	104	max_unsafe_computation) {
0b4e3aa0 A	105
0b4e3aa0 A	106	if (thread->sched_mode & TH_MODE_REALTIME) {
9bccf70c	107	thread->priority = DEPRESSPRI;
0b4e3aa0 A	108
	109	thread->safe_mode \|= TH_MODE_REALTIME;
	110	thread->sched_mode &= ~TH_MODE_REALTIME;
	111	}
1c79356b	112
55e303ae A	113	pset_share_incr(thread->processor_set);
55e303ae A	114
0b4e3aa0 A	115	thread->safe_release = sched_tick + sched_safe_duration;
0b4e3aa0 A	116	thread->sched_mode \|= (TH_MODE_FAILSAFE\|TH_MODE_TIMESHARE);
9bccf70c	117	thread->sched_mode &= ~TH_MODE_PREEMPT;
0b4e3aa0 A	118	}
0b4e3aa0 A	119	}
1c79356b A	120
1c79356b A	121	/*
9bccf70c	122	* Recompute scheduled priority if appropriate.
1c79356b	123	*/
0b4e3aa0 A	124	if (thread->sched_stamp != sched_tick)
	125	update_priority(thread);
	126	else
9bccf70c	127	if (thread->sched_mode & TH_MODE_TIMESHARE) {
91447636 A	128	register uint32_t delta;
	129
	130	thread_timer_delta(thread, delta);
	131
	132	/*
	133	* Accumulate timesharing usage only
	134	* during contention for processor
	135	* resources.
	136	*/
	137	if (thread->pri_shift < INT8_MAX)
	138	thread->sched_usage += delta;
	139
	140	thread->cpu_delta += delta;
9bccf70c A	141
	142	/*
	143	* Adjust the scheduled priority if
	144	* the thread has not been promoted
	145	* and is not depressed.
	146	*/
	147	if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
	148	!(thread->sched_mode & TH_MODE_ISDEPRESSED) )
	149	compute_my_priority(thread);
0b4e3aa0	150	}
1c79356b	151
0b4e3aa0 A	152	/*
	153	* This quantum is up, give this thread another.
	154	*/
55e303ae A	155	if (first_timeslice(myprocessor))
55e303ae A	156	myprocessor->timeslice--;
1c79356b	157
55e303ae	158	thread_quantum_init(thread);
0b4e3aa0 A	159	myprocessor->quantum_end += thread->current_quantum;
	160	timer_call_enter1(&myprocessor->quantum_timer,
	161	thread, myprocessor->quantum_end);
1c79356b	162
0b4e3aa0	163	thread_unlock(thread);
1c79356b	164
0b4e3aa0 A	165	/*
	166	* Check for and schedule ast if needed.
	167	*/
9bccf70c A	168	ast_check(myprocessor);
	169
	170	splx(s);
1c79356b	171	}
91447636 A	172
	173	/*
	174	* Define shifts for simulating (5/8) ** n
	175	*
	176	* Shift structures for holding update shifts. Actual computation
	177	* is usage = (usage >> shift1) +/- (usage >> abs(shift2)) where the
	178	* +/- is determined by the sign of shift 2.
	179	*/
	180	struct shift_data {
	181	int shift1;
	182	int shift2;
	183	};
	184
	185	#define SCHED_DECAY_TICKS 32
	186	static struct shift_data sched_decay_shifts[SCHED_DECAY_TICKS] = {
	187	{1,1},{1,3},{1,-3},{2,-7},{3,5},{3,-5},{4,-8},{5,7},
	188	{5,-7},{6,-10},{7,10},{7,-9},{8,-11},{9,12},{9,-11},{10,-13},
	189	{11,14},{11,-13},{12,-15},{13,17},{13,-15},{14,-17},{15,19},{16,18},
	190	{16,-19},{17,22},{18,20},{18,-20},{19,26},{20,22},{20,-22},{21,-27}
	191	};
	192
	193	/*
	194	* do_priority_computation:
	195	*
	196	* Calculate the timesharing priority based upon usage and load.
	197	*/
	198	#define do_priority_computation(thread, pri) \
	199	MACRO_BEGIN \
	200	(pri) = (thread)->priority /* start with base priority */ \
	201	- ((thread)->sched_usage >> (thread)->pri_shift); \
	202	if ((pri) < MINPRI_USER) \
	203	(pri) = MINPRI_USER; \
	204	else \
	205	if ((pri) > MAXPRI_KERNEL) \
	206	(pri) = MAXPRI_KERNEL; \
	207	MACRO_END
	208
	209	/*
	210	* set_priority:
	211	*
	212	* Set the base priority of the thread
	213	* and reset its scheduled priority.
	214	*
	215	* Called with the thread locked.
	216	*/
	217	void
	218	set_priority(
	219	register thread_t thread,
	220	register int priority)
	221	{
	222	thread->priority = priority;
	223	compute_priority(thread, FALSE);
	224	}
	225
	226	/*
	227	* compute_priority:
	228	*
	229	* Reset the scheduled priority of the thread
	230	* according to its base priority if the
	231	* thread has not been promoted or depressed.
	232	*
	233	* Called with the thread locked.
	234	*/
	235	void
236	compute_priority(
237	register thread_t thread,
238	boolean_t override_depress)
239	{
240	register int priority;
241
242	if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
243	(!(thread->sched_mode & TH_MODE_ISDEPRESSED) \|\|
244	override_depress ) ) {
245	if (thread->sched_mode & TH_MODE_TIMESHARE)
246	do_priority_computation(thread, priority);
247	else
248	priority = thread->priority;
249
250	set_sched_pri(thread, priority);
251	}
252	}
253
254	/*
255	* compute_my_priority:
256	*
257	* Reset the scheduled priority for
258	* a timesharing thread.
259	*
260	* Only for use on the current thread
261	* if timesharing and not depressed.
262	*
263	* Called with the thread locked.
264	*/
265	void
266	compute_my_priority(
267	register thread_t thread)
268	{
269	register int priority;
270
271	do_priority_computation(thread, priority);
272	assert(thread->runq == RUN_QUEUE_NULL);
273	thread->sched_pri = priority;
274	}
275
276	/*
277	* update_priority
278	*
279	* Perform housekeeping operations driven by scheduler tick.
280	*
281	* Called with the thread locked.
282	*/
283	void
284	update_priority(
285	register thread_t thread)
286	{
287	register unsigned ticks;
288	register uint32_t delta;
289
290	ticks = sched_tick - thread->sched_stamp;
291	assert(ticks != 0);
292	thread->sched_stamp += ticks;
293	thread->pri_shift = thread->processor_set->pri_shift;
294
295	/*
296	* Gather cpu usage data.
297	*/
298	thread_timer_delta(thread, delta);
299	if (ticks < SCHED_DECAY_TICKS) {
300	register struct shift_data *shiftp;
301
302	/*
303	* Accumulate timesharing usage only
304	* during contention for processor
305	* resources.
306	*/
307	if (thread->pri_shift < INT8_MAX)
308	thread->sched_usage += delta;
309
310	thread->cpu_usage += delta + thread->cpu_delta;
311	thread->cpu_delta = 0;
312
313	shiftp = &sched_decay_shifts[ticks];
314	if (shiftp->shift2 > 0) {
315	thread->cpu_usage =
316	(thread->cpu_usage >> shiftp->shift1) +
317	(thread->cpu_usage >> shiftp->shift2);
318	thread->sched_usage =
319	(thread->sched_usage >> shiftp->shift1) +
320	(thread->sched_usage >> shiftp->shift2);
321	}
322	else {
323	thread->cpu_usage =
324	(thread->cpu_usage >> shiftp->shift1) -
325	(thread->cpu_usage >> -(shiftp->shift2));
326	thread->sched_usage =
327	(thread->sched_usage >> shiftp->shift1) -
328	(thread->sched_usage >> -(shiftp->shift2));
329	}
330	}
331	else {
332	thread->cpu_usage = thread->cpu_delta = 0;
333	thread->sched_usage = 0;
334	}
335
336	/*
337	* Check for fail-safe release.
338	*/
339	if ( (thread->sched_mode & TH_MODE_FAILSAFE) &&
340	thread->sched_stamp >= thread->safe_release ) {
341	if (!(thread->safe_mode & TH_MODE_TIMESHARE)) {
342	if (thread->safe_mode & TH_MODE_REALTIME) {
343	thread->priority = BASEPRI_RTQUEUES;
344
345	thread->sched_mode \|= TH_MODE_REALTIME;
346	}
347
348	thread->sched_mode &= ~TH_MODE_TIMESHARE;
349
350	if (thread->state & TH_RUN)
351	pset_share_decr(thread->processor_set);
352
353	if (!(thread->sched_mode & TH_MODE_ISDEPRESSED))
354	set_sched_pri(thread, thread->priority);
355	}
356
357	thread->safe_mode = 0;
358	thread->sched_mode &= ~TH_MODE_FAILSAFE;
359	}
360
361	/*
362	* Recompute scheduled priority if appropriate.
363	*/
364	if ( (thread->sched_mode & TH_MODE_TIMESHARE) &&
365	!(thread->sched_mode & TH_MODE_PROMOTED) &&
366	!(thread->sched_mode & TH_MODE_ISDEPRESSED) ) {
367	register int new_pri;
368
369	do_priority_computation(thread, new_pri);
370	if (new_pri != thread->sched_pri) {
371	run_queue_t runq;
372
373	runq = run_queue_remove(thread);
374	thread->sched_pri = new_pri;
375	if (runq != RUN_QUEUE_NULL)
376	thread_setrun(thread, SCHED_TAILQ);
377	}
378	}
379	}