MEDIUM: queue: unlock as soon as possible
There's no point keeping the server's queue lock after seeing that the
server's queue is empty, just like there's no need to keep the proxy's
lock when its queue is empty. This patch checks for emptiness and
releases these locks as soon as possible.
With this the performance increased from 524k to 530k on 16 threads
with round-robin.
diff --git a/src/queue.c b/src/queue.c
index 8db2da2..e16331f 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -270,20 +270,23 @@
u32 pkey, ppkey;
p = NULL;
- HA_SPIN_LOCK(QUEUE_LOCK, &srv->queue.lock);
- if (srv->queue.length)
+ if (srv->queue.length) {
+ HA_SPIN_LOCK(QUEUE_LOCK, &srv->queue.lock);
p = pendconn_first(&srv->queue.head);
+ if (!p)
+ HA_SPIN_UNLOCK(QUEUE_LOCK, &srv->queue.lock);
+ }
pp = NULL;
- HA_SPIN_LOCK(QUEUE_LOCK, &px->queue.lock);
- if (px_ok && px->queue.length)
+ if (px_ok && px->queue.length) {
+ HA_SPIN_LOCK(QUEUE_LOCK, &px->queue.lock);
pp = pendconn_first(&px->queue.head);
+ if (!pp)
+ HA_SPIN_UNLOCK(QUEUE_LOCK, &px->queue.lock);
+ }
- if (!p && !pp) {
- HA_SPIN_UNLOCK(QUEUE_LOCK, &px->queue.lock);
- HA_SPIN_UNLOCK(QUEUE_LOCK, &srv->queue.lock);
+ if (!p && !pp)
return NULL;
- }
else if (!pp)
goto use_p; /* p != NULL */
else if (!p)
@@ -311,16 +314,18 @@
use_pp:
/* Let's switch from the server pendconn to the proxy pendconn */
+ if (p)
+ HA_SPIN_UNLOCK(QUEUE_LOCK, &srv->queue.lock);
__pendconn_unlink_prx(pp);
HA_SPIN_UNLOCK(QUEUE_LOCK, &px->queue.lock);
- HA_SPIN_UNLOCK(QUEUE_LOCK, &srv->queue.lock);
_HA_ATOMIC_INC(&px->queue.idx);
_HA_ATOMIC_DEC(&px->queue.length);
_HA_ATOMIC_DEC(&px->totpend);
p = pp;
goto unlinked;
use_p:
- HA_SPIN_UNLOCK(QUEUE_LOCK, &px->queue.lock);
+ if (pp)
+ HA_SPIN_UNLOCK(QUEUE_LOCK, &px->queue.lock);
__pendconn_unlink_srv(p);
HA_SPIN_UNLOCK(QUEUE_LOCK, &srv->queue.lock);
_HA_ATOMIC_INC(&srv->queue.idx);