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Merged from sys/i386/i386/machdep.c revision 1.410.

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This commit is contained in:
KATO Takenori 2000-09-22 12:54:50 +00:00
parent 7dd8cc5686
commit 3f605d2ffc
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=66248
2 changed files with 74 additions and 0 deletions
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37
sys/pc98/i386/machdep.c
View File

@ -73,6 +73,7 @@
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/bus.h>
#include <sys/eventhandler.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
@ -1005,6 +1006,42 @@ cpu_halt(void)
__asm__ ("hlt");
}
/*
* Hook to idle the CPU when possible. This currently only works in
* the !SMP case, as there is no clean way to ensure that a CPU will be
* woken when there is work available for it.
*/
#ifndef SMP
static int cpu_idle_hlt = 1;
SYSCTL_INT(_machdep, OID_AUTO, cpu_idle_hlt, CTLFLAG_RW, &cpu_idle_hlt, 0, "Idle loop HLT enable");
/*
* Note that we have to be careful here to avoid a race between checking
* procrunnable() and actually halting. If we don't do this, we may waste
* the time between calling hlt and the next interrupt even though there
* is a runnable process.
*/
static void
cpu_idle(void *junk, int count)
{
if (cpu_idle_hlt){
disable_intr();
if (procrunnable()) {
enable_intr();
} else {
enable_intr();
__asm__ ("hlt");
}
}
}
static void cpu_idle_register(void *junk)
{
EVENTHANDLER_FAST_REGISTER(idle_event, cpu_idle, NULL, IDLE_PRI_LAST);
}
SYSINIT(cpu_idle_register, SI_SUB_SCHED_IDLE, SI_ORDER_SECOND, cpu_idle_register, NULL)
#endif /* !SMP */
/*
* Clear registers on exec
*/

37
sys/pc98/pc98/machdep.c
View File

@ -73,6 +73,7 @@
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/bus.h>
#include <sys/eventhandler.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
@ -1005,6 +1006,42 @@ cpu_halt(void)
__asm__ ("hlt");
}
/*
* Hook to idle the CPU when possible. This currently only works in
* the !SMP case, as there is no clean way to ensure that a CPU will be
* woken when there is work available for it.
*/
#ifndef SMP
static int cpu_idle_hlt = 1;
SYSCTL_INT(_machdep, OID_AUTO, cpu_idle_hlt, CTLFLAG_RW, &cpu_idle_hlt, 0, "Idle loop HLT enable");
/*
* Note that we have to be careful here to avoid a race between checking
* procrunnable() and actually halting. If we don't do this, we may waste
* the time between calling hlt and the next interrupt even though there
* is a runnable process.
*/
static void
cpu_idle(void *junk, int count)
{
if (cpu_idle_hlt){
disable_intr();
if (procrunnable()) {
enable_intr();
} else {
enable_intr();
__asm__ ("hlt");
}
}
}
static void cpu_idle_register(void *junk)
{
EVENTHANDLER_FAST_REGISTER(idle_event, cpu_idle, NULL, IDLE_PRI_LAST);
}
SYSINIT(cpu_idle_register, SI_SUB_SCHED_IDLE, SI_ORDER_SECOND, cpu_idle_register, NULL)
#endif /* !SMP */
/*
* Clear registers on exec
*/