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sched.h revision 1.12 
      1 /*	$NetBSD: sched.h,v 1.12 2018/10/23 03:56:47 riastradh Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _LINUX_SCHED_H_
     33 #define _LINUX_SCHED_H_
     34 
     35 #include <sys/param.h>
     36 #include <sys/kernel.h>
     37 #include <sys/proc.h>
     38 
     39 #include <asm/param.h>
     40 #include <asm/barrier.h>
     41 #include <asm/processor.h>
     42 #include <linux/errno.h>
     43 
     44 #define	TASK_COMM_LEN	MAXCOMLEN
     45 
     46 #define	MAX_SCHEDULE_TIMEOUT	(INT_MAX/2)	/* paranoia */
     47 
     48 #define	current	curproc
     49 
     50 static inline pid_t
     51 task_pid_nr(struct proc *p)
     52 {
     53 	return p->p_pid;
     54 }
     55 
     56 static inline long
     57 schedule_timeout_uninterruptible(long timeout)
     58 {
     59 	long remain;
     60 	int start, end;
     61 
     62 	if (cold) {
     63 		unsigned us;
     64 		if (hz <= 1000) {
     65 			unsigned ms = hztoms(MIN(timeout, mstohz(INT_MAX)));
     66 			us = MIN(ms, INT_MAX/1000)*1000;
     67 		} else if (hz <= 1000000) {
     68 			us = MIN(timeout, (INT_MAX/1000000)/hz)*hz*1000000;
     69 		} else {
     70 			us = timeout/(1000000/hz);
     71 		}
     72 		DELAY(us);
     73 		return 0;
     74 	}
     75 
     76 	start = hardclock_ticks;
     77 	/* Caller is expected to loop anyway, so no harm in truncating.  */
     78 	(void)kpause("loonix", false /*!intr*/, MIN(timeout, INT_MAX), NULL);
     79 	end = hardclock_ticks;
     80 
     81 	remain = timeout - (end - start);
     82 	return remain > 0 ? remain : 0;
     83 }
     84 
     85 static inline void
     86 cond_resched(void)
     87 {
     88 
     89 	if (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD)
     90 		preempt();
     91 }
     92 
     93 #endif  /* _LINUX_SCHED_H_ */
     94