Redundant timer rearm optimisation by Anders Melchiorsen.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3823 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
balrog 2007-12-16 13:17:12 +00:00
parent b01bcae61c
commit b99dc0d1a4

12
vl.c
View File

@ -822,6 +822,7 @@ struct qemu_alarm_timer {
}; };
#define ALARM_FLAG_DYNTICKS 0x1 #define ALARM_FLAG_DYNTICKS 0x1
#define ALARM_FLAG_MODIFIED 0x2
static inline int alarm_has_dynticks(struct qemu_alarm_timer *t) static inline int alarm_has_dynticks(struct qemu_alarm_timer *t)
{ {
@ -833,6 +834,11 @@ static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
if (!alarm_has_dynticks(t)) if (!alarm_has_dynticks(t))
return; return;
if (!(t->flags & ALARM_FLAG_MODIFIED))
return;
t->flags &= ~(ALARM_FLAG_MODIFIED);
t->rearm(t); t->rearm(t);
} }
@ -995,6 +1001,8 @@ void qemu_del_timer(QEMUTimer *ts)
{ {
QEMUTimer **pt, *t; QEMUTimer **pt, *t;
alarm_timer->flags |= ALARM_FLAG_MODIFIED;
/* NOTE: this code must be signal safe because /* NOTE: this code must be signal safe because
qemu_timer_expired() can be called from a signal. */ qemu_timer_expired() can be called from a signal. */
pt = &active_timers[ts->clock->type]; pt = &active_timers[ts->clock->type];
@ -1067,7 +1075,6 @@ static void qemu_run_timers(QEMUTimer **ptimer_head, int64_t current_time)
/* run the callback (the timer list can be modified) */ /* run the callback (the timer list can be modified) */
ts->cb(ts->opaque); ts->cb(ts->opaque);
} }
qemu_rearm_alarm_timer(alarm_timer);
} }
int64_t qemu_get_clock(QEMUClock *clock) int64_t qemu_get_clock(QEMUClock *clock)
@ -1187,6 +1194,7 @@ static void host_alarm_handler(int host_signum)
CPUState *env = next_cpu; CPUState *env = next_cpu;
if (env) { if (env) {
alarm_timer->flags |= ALARM_FLAG_MODIFIED;
/* stop the currently executing cpu because a timer occured */ /* stop the currently executing cpu because a timer occured */
cpu_interrupt(env, CPU_INTERRUPT_EXIT); cpu_interrupt(env, CPU_INTERRUPT_EXIT);
#ifdef USE_KQEMU #ifdef USE_KQEMU
@ -7364,6 +7372,8 @@ void main_loop_wait(int timeout)
qemu_run_timers(&active_timers[QEMU_TIMER_REALTIME], qemu_run_timers(&active_timers[QEMU_TIMER_REALTIME],
qemu_get_clock(rt_clock)); qemu_get_clock(rt_clock));
qemu_rearm_alarm_timer(alarm_timer);
/* Check bottom-halves last in case any of the earlier events triggered /* Check bottom-halves last in case any of the earlier events triggered
them. */ them. */
qemu_bh_poll(); qemu_bh_poll();