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authorzhenwei pi <pizhenwei@bytedance.com>2023-07-28 10:20:00 +0800
committerHanna Czenczek <hreitz@redhat.com>2023-08-29 10:49:24 +0200
commitd85b08c6e27d796dbb653b8ae9584080361c1498 (patch)
tree62dc1302719515bedc05930a114af33012d981ee /util
parent1322f63df52e23ecf47cc9a5842ec3099c517183 (diff)
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throttle: support read-only and write-only
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. Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com> Message-Id: <20230728022006.1098509-4-pizhenwei@bytedance.com> Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Diffstat (limited to 'util')
-rw-r--r--util/throttle.c42
1 files changed, 28 insertions, 14 deletions
diff --git a/util/throttle.c b/util/throttle.c
index 5642e61..0439028 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -199,12 +199,15 @@ static bool throttle_compute_timer(ThrottleState *ts,
void throttle_timers_attach_aio_context(ThrottleTimers *tt,
AioContext *new_context)
{
- tt->timers[THROTTLE_READ] =
- aio_timer_new(new_context, tt->clock_type, SCALE_NS,
- tt->timer_cb[THROTTLE_READ], tt->timer_opaque);
- tt->timers[THROTTLE_WRITE] =
- aio_timer_new(new_context, tt->clock_type, SCALE_NS,
- tt->timer_cb[THROTTLE_WRITE], tt->timer_opaque);
+ ThrottleDirection dir;
+
+ for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
+ if (tt->timer_cb[dir]) {
+ tt->timers[dir] =
+ aio_timer_new(new_context, tt->clock_type, SCALE_NS,
+ tt->timer_cb[dir], tt->timer_opaque);
+ }
+ }
}
/*
@@ -235,6 +238,7 @@ 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 +251,9 @@ 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;
@@ -256,10 +262,10 @@ static void throttle_timer_destroy(QEMUTimer **timer)
/* Remove timers from event loop */
void throttle_timers_detach_aio_context(ThrottleTimers *tt)
{
- int i;
+ ThrottleDirection dir;
- for (i = 0; i < THROTTLE_MAX; i++) {
- throttle_timer_destroy(&tt->timers[i]);
+ for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
+ throttle_timer_destroy(&tt->timers[dir]);
}
}
@@ -272,8 +278,12 @@ void throttle_timers_destroy(ThrottleTimers *tt)
/* is any throttling timer configured */
bool throttle_timers_are_initialized(ThrottleTimers *tt)
{
- if (tt->timers[0]) {
- return true;
+ ThrottleDirection dir;
+
+ for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++) {
+ if (tt->timers[dir]) {
+ return true;
+ }
}
return false;
@@ -424,8 +434,12 @@ bool throttle_schedule_timer(ThrottleState *ts,
{
int64_t now = qemu_clock_get_ns(tt->clock_type);
int64_t next_timestamp;
+ QEMUTimer *timer;
bool must_wait;
+ timer = is_write ? tt->timers[THROTTLE_WRITE] : tt->timers[THROTTLE_READ];
+ assert(timer);
+
must_wait = throttle_compute_timer(ts,
is_write,
now,
@@ -437,12 +451,12 @@ bool throttle_schedule_timer(ThrottleState *ts,
}
/* request throttled and timer pending -> do nothing */
- if (timer_pending(tt->timers[is_write])) {
+ if (timer_pending(timer)) {
return true;
}
/* request throttled and timer not pending -> arm timer */
- timer_mod(tt->timers[is_write], next_timestamp);
+ timer_mod(timer, next_timestamp);
return true;
}