NetBSD/sys/kern/kern_idle.c

105 lines
3.0 KiB
C

/* $NetBSD: kern_idle.c,v 1.7 2007/11/06 00:42:41 ad Exp $ */
/*-
* Copyright (c)2002, 2006, 2007 YAMAMOTO Takashi,
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_idle.c,v 1.7 2007/11/06 00:42:41 ad Exp $");
#include <sys/param.h>
#include <sys/cpu.h>
#include <sys/idle.h>
#include <sys/kthread.h>
#include <sys/lockdebug.h>
#include <sys/kmem.h>
#include <sys/proc.h>
#include <uvm/uvm.h>
#include <uvm/uvm_extern.h>
void
idle_loop(void *dummy)
{
struct cpu_info *ci = curcpu();
struct lwp *l = curlwp;
/* Update start time for this thread. */
microtime(&l->l_stime);
KERNEL_UNLOCK_ALL(l, NULL);
l->l_stat = LSONPROC;
while (1 /* CONSTCOND */) {
KERNEL_LOCK_ASSERT_UNLOCKED();
LOCKDEBUG_BARRIER(NULL, 0);
KASSERT((l->l_flag & LW_IDLE) != 0);
KASSERT(ci == curcpu());
KASSERT(l == curlwp);
KASSERT(CURCPU_IDLE_P());
KASSERT(l->l_priority == PRI_IDLE);
if (uvm.page_idle_zero) {
if (sched_curcpu_runnable_p()) {
goto schedule;
}
uvm_pageidlezero();
}
if (!sched_curcpu_runnable_p()) {
cpu_idle();
if (!sched_curcpu_runnable_p() &&
!ci->ci_want_resched) {
continue;
}
}
schedule:
KASSERT(l->l_mutex == &l->l_cpu->ci_schedstate.spc_lwplock);
lwp_lock(l);
mi_switch(l);
KASSERT(curlwp == l);
KASSERT(l->l_stat == LSONPROC);
}
}
int
create_idle_lwp(struct cpu_info *ci)
{
lwp_t *l;
int error;
KASSERT(ci->ci_data.cpu_idlelwp == NULL);
error = kthread_create(PRI_IDLE, KTHREAD_MPSAFE | KTHREAD_IDLE,
ci, idle_loop, NULL, &l, "idle/%d", (int)ci->ci_cpuid);
if (error != 0)
panic("create_idle_lwp: error %d", error);
lwp_lock(l);
l->l_flag |= LW_IDLE;
lwp_unlock(l);
l->l_cpu = ci;
ci->ci_data.cpu_idlelwp = l;
return error;
}