MINOR: threads/queue: Get rid of THREAD_WANT_SYNC in the queue code.

Now that we can wake one thread sleeping in the poller, we don't have to
use THREAD_WANT_SYNC any more.

This gives a significant performance boost on highly contended accesses
(servers with maxconn 1), showing a jump from 21k to 31k conn/s on a
test involving 8 threads.

diff --git a/src/queue.c b/src/queue.c
index 6304d61b33cc6dad95fb3bd0d24dddcc3602b771..173ef76f64d0d61a386bf355148671e4b05e20b5 100644 (file)
--- a/src/queue.c
+++ b/src/queue.c
@@ -200,7 +200,6 @@ static int pendconn_process_next_strm(struct server *srv, struct proxy *px)
 {
        struct pendconn *p = NULL;
        struct server   *rsrv;
-       int remote;
 
        rsrv = srv->track;
        if (!rsrv)
@@ -240,11 +239,9 @@ static int pendconn_process_next_strm(struct server *srv, struct proxy *px)
                px->lbprm.server_take_conn(srv);
        __stream_add_srv_conn(p->strm, srv);
 
-       remote = !(p->strm->task->thread_mask & tid_bit);
        task_wakeup(p->strm->task, TASK_WOKEN_RES);
 
-       /* Returns 1 if the current thread can process the stream, otherwise returns 2. */
-       return remote ? 2 : 1;
+       return 1;
 }
 
 /* Manages a server's connection queue. This function will try to dequeue as
@@ -253,7 +250,7 @@ static int pendconn_process_next_strm(struct server *srv, struct proxy *px)
 void process_srv_queue(struct server *s)
 {
        struct proxy  *p = s->proxy;
-       int maxconn, remote = 0;
+       int maxconn;
 
        HA_SPIN_LOCK(PROXY_LOCK,  &p->lock);
        HA_SPIN_LOCK(SERVER_LOCK, &s->lock);
@@ -262,13 +259,9 @@ void process_srv_queue(struct server *s)
                int ret = pendconn_process_next_strm(s, p);
                if (!ret)
                        break;
-               remote |= (ret == 2);
        }
        HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
        HA_SPIN_UNLOCK(PROXY_LOCK,  &p->lock);
-
-       if (remote)
-               THREAD_WANT_SYNC();
 }
 
 /* Adds the stream <strm> to the pending connection list of server <strm>->srv
@@ -333,7 +326,6 @@ int pendconn_redistribute(struct server *s)
 {
        struct pendconn *p, *pback;
        int xferred = 0;
-       int remote = 0;
 
        /* The REDISP option was specified. We will ignore cookie and force to
         * balance or use the dispatcher. */
@@ -349,13 +341,9 @@ int pendconn_redistribute(struct server *s)
                __pendconn_unlink(p);
                p->strm_flags &= ~(SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
 
-               remote |= !(p->strm->task->thread_mask & tid_bit);
                task_wakeup(p->strm->task, TASK_WOKEN_RES);
        }
        HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
-
-       if (remote)
-               THREAD_WANT_SYNC();
        return xferred;
 }
 
@@ -368,7 +356,6 @@ int pendconn_grab_from_px(struct server *s)
 {
        struct pendconn *p, *pback;
        int maxconn, xferred = 0;
-       int remote = 0;
 
        if (!srv_currently_usable(s))
                return 0;
@@ -382,14 +369,10 @@ int pendconn_grab_from_px(struct server *s)
                __pendconn_unlink(p);
                p->target = s;
 
-               remote |= !(p->strm->task->thread_mask & tid_bit);
                task_wakeup(p->strm->task, TASK_WOKEN_RES);
                xferred++;
        }
        HA_SPIN_UNLOCK(PROXY_LOCK, &s->proxy->lock);
-
-       if (remote)
-               THREAD_WANT_SYNC();
        return xferred;
 }