Home | History | Annotate | Line # | Download | only in linux
sched.h revision 1.19 
      1 /*	$NetBSD: sched.h,v 1.19 2021/12/19 11:49:12 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 
     37 #include <sys/cdefs.h>
     38 #include <sys/kernel.h>
     39 #include <sys/proc.h>
     40 
     41 #include <asm/barrier.h>
     42 #include <asm/param.h>
     43 #include <asm/processor.h>
     44 
     45 #include <linux/device.h>
     46 #include <linux/errno.h>
     47 
     48 struct seq_file;
     49 
     50 #define	TASK_COMM_LEN	MAXCOMLEN
     51 
     52 #define	MAX_SCHEDULE_TIMEOUT	(INT_MAX/2)	/* paranoia */
     53 
     54 #define	TASK_UNINTERRUPTIBLE	__BIT(0)
     55 
     56 #define	current	curproc
     57 
     58 static inline pid_t
     59 task_pid_nr(struct proc *p)
     60 {
     61 	return p->p_pid;
     62 }
     63 
     64 static inline long
     65 schedule_timeout_uninterruptible(long timeout)
     66 {
     67 	long remain;
     68 	int start, end;
     69 
     70 	if (cold) {
     71 		unsigned us;
     72 		if (hz <= 1000) {
     73 			unsigned ms = hztoms(MIN((unsigned long)timeout,
     74 			    mstohz(INT_MAX)));
     75 			us = MIN(ms, INT_MAX/1000)*1000;
     76 		} else if (hz <= 1000000) {
     77 			us = MIN(timeout, (INT_MAX/1000000)/hz)*hz*1000000;
     78 		} else {
     79 			us = timeout/(1000000/hz);
     80 		}
     81 		DELAY(us);
     82 		return 0;
     83 	}
     84 
     85 	start = getticks();
     86 	/* Caller is expected to loop anyway, so no harm in truncating.  */
     87 	(void)kpause("loonix", false /*!intr*/, MIN(timeout, INT_MAX), NULL);
     88 	end = getticks();
     89 
     90 	remain = timeout - (end - start);
     91 	return remain > 0 ? remain : 0;
     92 }
     93 
     94 static inline bool
     95 need_resched(void)
     96 {
     97 	/* XXX kpreempt_disable */
     98 	/* XXX ci_want_resched */
     99 	return (curcpu()->ci_schedstate.spc_flags & SPCF_SHOULDYIELD);
    100 }
    101 
    102 static inline void
    103 cond_resched(void)
    104 {
    105 
    106 	preempt_point();
    107 }
    108 
    109 static inline bool
    110 signal_pending_state(int state, struct proc *p)
    111 {
    112 
    113 	KASSERT(p == current);
    114 	if (state & TASK_UNINTERRUPTIBLE)
    115 		return false;
    116 	return sigispending(curlwp, 0);
    117 }
    118 
    119 #endif  /* _LINUX_SCHED_H_ */
    120