Re: Re: [PATCH 3/5] throttle: support read-only and write-only

2023-06-26 Thread zhenwei pi 




On 6/27/23 05:38, Alberto Garcia wrote:

On Sun 25 Jun 2023 04:56:29 PM +08, zhenwei pi wrote:

  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);
+}
  }


If now any of the timers can be NULL, don't you want to add additional
checks / assertions to (at least) throttle_schedule_timer() ?

Berto


OK.

--
zhenwei pi

Re: [PATCH 3/5] throttle: support read-only and write-only

2023-06-26 Thread Alberto Garcia 
On Sun 25 Jun 2023 04:56:29 PM +08, zhenwei pi wrote:
>  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);
> +}
>  }

If now any of the timers can be NULL, don't you want to add additional
checks / assertions to (at least) throttle_schedule_timer() ?

Berto

[PATCH 3/5] throttle: support read-only and write-only

2023-06-25 Thread zhenwei pi 
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