Only one direction is necessary in several scenarios:
- a read-only disk
- operations on a device are considered as *write* only. For example,
encrypt/decrypt/sign/verify operations on a cryptodev use a single
*write* timer(read timer callback is defined, but never invoked).
Allow a single direction in throttle, this reduces memory, and uplayer
does not need a dummy callback any more.
Signed-off-by: zhenwei pi
---
util/throttle.c | 24
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/util/throttle.c b/util/throttle.c
index c1cc24831c..01faee783c 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -199,12 +199,17 @@ static bool throttle_compute_timer(ThrottleState *ts,
void throttle_timers_attach_aio_context(ThrottleTimers *tt,
AioContext *new_context)
{
-tt->timers[THROTTLE_TIMER_READ] =
-aio_timer_new(new_context, tt->clock_type, SCALE_NS,
- tt->timer_cb[THROTTLE_TIMER_READ], tt->timer_opaque);
-tt->timers[THROTTLE_TIMER_WRITE] =
-aio_timer_new(new_context, tt->clock_type, SCALE_NS,
- tt->timer_cb[THROTTLE_TIMER_WRITE], tt->timer_opaque);
+if (tt->timer_cb[THROTTLE_TIMER_READ]) {
+tt->timers[THROTTLE_TIMER_READ] =
+aio_timer_new(new_context, tt->clock_type, SCALE_NS,
+ tt->timer_cb[THROTTLE_TIMER_READ], tt->timer_opaque);
+}
+
+if (tt->timer_cb[THROTTLE_TIMER_WRITE]) {
+tt->timers[THROTTLE_TIMER_WRITE] =
+aio_timer_new(new_context, tt->clock_type, SCALE_NS,
+ tt->timer_cb[THROTTLE_TIMER_WRITE],
tt->timer_opaque);
+}
}
/*
@@ -235,6 +240,7 @@ void throttle_timers_init(ThrottleTimers *tt,
QEMUTimerCB *write_timer_cb,
void *timer_opaque)
{
+assert(read_timer_cb || write_timer_cb);
memset(tt, 0, sizeof(ThrottleTimers));
tt->clock_type = clock_type;
@@ -247,7 +253,9 @@ void throttle_timers_init(ThrottleTimers *tt,
/* destroy a timer */
static void throttle_timer_destroy(QEMUTimer **timer)
{
-assert(*timer != NULL);
+if (*timer == NULL) {
+return;
+}
timer_free(*timer);
*timer = NULL;
@@ -272,7 +280,7 @@ void throttle_timers_destroy(ThrottleTimers *tt)
/* is any throttling timer configured */
bool throttle_timers_are_initialized(ThrottleTimers *tt)
{
-if (tt->timers[0]) {
+if (tt->timers[THROTTLE_TIMER_READ] || tt->timers[THROTTLE_TIMER_WRITE]) {
return true;
}
--
2.34.1