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kern_idle.c revision 1.4.4.1
      1  1.4.4.1  joerg /*	$NetBSD: kern_idle.c,v 1.4.4.1 2007/10/02 18:28:59 joerg Exp $	*/
      2      1.2   yamt 
      3      1.2   yamt /*-
      4      1.2   yamt  * Copyright (c)2002, 2006, 2007 YAMAMOTO Takashi,
      5      1.2   yamt  * All rights reserved.
      6      1.2   yamt  *
      7      1.2   yamt  * Redistribution and use in source and binary forms, with or without
      8      1.2   yamt  * modification, are permitted provided that the following conditions
      9      1.2   yamt  * are met:
     10      1.2   yamt  * 1. Redistributions of source code must retain the above copyright
     11      1.2   yamt  *    notice, this list of conditions and the following disclaimer.
     12      1.2   yamt  * 2. Redistributions in binary form must reproduce the above copyright
     13      1.2   yamt  *    notice, this list of conditions and the following disclaimer in the
     14      1.2   yamt  *    documentation and/or other materials provided with the distribution.
     15      1.2   yamt  *
     16      1.2   yamt  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17      1.2   yamt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18      1.2   yamt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19      1.2   yamt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20      1.2   yamt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21      1.2   yamt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22      1.2   yamt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23      1.2   yamt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24      1.2   yamt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25      1.2   yamt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26      1.2   yamt  * SUCH DAMAGE.
     27      1.2   yamt  */
     28      1.2   yamt 
     29      1.2   yamt #include <sys/cdefs.h>
     30      1.2   yamt 
     31  1.4.4.1  joerg __KERNEL_RCSID(0, "$NetBSD: kern_idle.c,v 1.4.4.1 2007/10/02 18:28:59 joerg Exp $");
     32      1.2   yamt 
     33      1.2   yamt #include <sys/param.h>
     34      1.2   yamt #include <sys/cpu.h>
     35      1.2   yamt #include <sys/idle.h>
     36      1.2   yamt #include <sys/lwp.h>
     37      1.2   yamt #include <sys/lockdebug.h>
     38      1.2   yamt #include <sys/kmem.h>
     39      1.4     ad #include <sys/proc.h>
     40      1.2   yamt 
     41      1.2   yamt #include <uvm/uvm.h>
     42      1.2   yamt #include <uvm/uvm_extern.h>
     43      1.2   yamt 
     44      1.2   yamt #define	PIDLELWP	(MAXPRI + 1)	/* lowest priority */
     45      1.2   yamt 
     46      1.2   yamt void
     47      1.2   yamt idle_loop(void *dummy)
     48      1.2   yamt {
     49      1.2   yamt 	struct cpu_info *ci = curcpu();
     50      1.2   yamt 	struct lwp *l = curlwp;
     51      1.2   yamt 
     52      1.2   yamt 	KERNEL_UNLOCK_ALL(l, NULL);
     53      1.2   yamt 	l->l_usrpri = PIDLELWP;
     54      1.3     ad 	l->l_priority = l->l_usrpri;
     55      1.2   yamt 	l->l_stat = LSONPROC;
     56      1.2   yamt 	while (1 /* CONSTCOND */) {
     57      1.2   yamt 		KERNEL_LOCK_ASSERT_UNLOCKED();
     58      1.2   yamt 		LOCKDEBUG_BARRIER(NULL, 0);
     59      1.2   yamt 		KASSERT((l->l_flag & LW_IDLE) != 0);
     60      1.2   yamt 		KASSERT(ci == curcpu());
     61      1.2   yamt 		KASSERT(l == curlwp);
     62      1.2   yamt 		KASSERT(CURCPU_IDLE_P());
     63      1.2   yamt 		KASSERT(l->l_usrpri == PIDLELWP);
     64      1.2   yamt 
     65      1.2   yamt 		if (uvm.page_idle_zero) {
     66      1.2   yamt 			if (sched_curcpu_runnable_p()) {
     67      1.2   yamt 				goto schedule;
     68      1.2   yamt 			}
     69      1.2   yamt 			uvm_pageidlezero();
     70      1.2   yamt 		}
     71      1.2   yamt 		if (!sched_curcpu_runnable_p()) {
     72      1.2   yamt 			cpu_idle();
     73  1.4.4.1  joerg 			if (!sched_curcpu_runnable_p() &&
     74  1.4.4.1  joerg 			    !ci->ci_want_resched) {
     75      1.2   yamt 				continue;
     76      1.2   yamt 			}
     77      1.2   yamt 		}
     78      1.2   yamt schedule:
     79      1.2   yamt 		KASSERT(l->l_mutex == &l->l_cpu->ci_schedstate.spc_lwplock);
     80      1.2   yamt 		lwp_lock(l);
     81      1.2   yamt 		mi_switch(l);
     82      1.2   yamt 		KASSERT(curlwp == l);
     83      1.2   yamt 		KASSERT(l->l_stat == LSONPROC);
     84      1.2   yamt 	}
     85      1.2   yamt }
     86      1.2   yamt 
     87      1.2   yamt int
     88      1.2   yamt create_idle_lwp(struct cpu_info *ci)
     89      1.2   yamt {
     90      1.2   yamt 	struct proc *p = &proc0;
     91      1.2   yamt 	struct lwp *l;
     92      1.2   yamt 	char *name;
     93      1.2   yamt 	vaddr_t uaddr;
     94      1.2   yamt 	bool inmem;
     95      1.2   yamt 	cpuid_t cpuid;
     96      1.2   yamt 	int error;
     97      1.2   yamt 
     98      1.2   yamt 	KASSERT(ci->ci_data.cpu_idlelwp == NULL);
     99      1.2   yamt 	inmem = uvm_uarea_alloc(&uaddr);
    100      1.2   yamt 	if (uaddr == 0) {
    101      1.2   yamt 		return ENOMEM;
    102      1.2   yamt 	}
    103      1.2   yamt 	error = newlwp(&lwp0, p, uaddr, inmem, 0, NULL, 0, idle_loop, NULL, &l);
    104      1.2   yamt 	if (error != 0) {
    105      1.2   yamt 		panic("create_idle_lwp: newlwp failed");
    106      1.2   yamt 	}
    107      1.3     ad 	uvm_lwp_hold(l);
    108      1.2   yamt 	l->l_flag |= (LW_IDLE | LW_BOUND);
    109      1.2   yamt 	l->l_cpu = ci;
    110      1.2   yamt 	l->l_mutex = &ci->ci_schedstate.spc_lwplock;
    111      1.2   yamt 	ci->ci_data.cpu_idlelwp = l;
    112      1.2   yamt 	name = kmem_alloc(MAXCOMLEN, KM_NOSLEEP);
    113      1.2   yamt 	if (name != NULL) {
    114      1.2   yamt #ifdef MULTIPROCESSOR		/* XXX should be mandatory */
    115      1.2   yamt 		cpuid = ci->ci_cpuid;
    116      1.2   yamt #else
    117      1.2   yamt 		cpuid = 0;
    118      1.2   yamt #endif
    119      1.3     ad 		snprintf(name, MAXCOMLEN, "idle/%d", (int)cpuid);
    120      1.2   yamt 		lwp_lock(l);
    121      1.2   yamt 		l->l_name = name;
    122      1.2   yamt 		lwp_unlock(l);
    123      1.2   yamt 	}
    124      1.2   yamt 	return error;
    125      1.2   yamt }
    126