MEDIUM: connections: Don't use a lock when moving connections to remove.
Make it so we don't have to take a lock while moving a connection from
the idle list to the toremove_list by taking advantage of the MT_LIST.
diff --git a/include/haproxy/connection.h b/include/haproxy/connection.h
index 6e8862b..f8f235c 100644
--- a/include/haproxy/connection.h
+++ b/include/haproxy/connection.h
@@ -494,9 +494,7 @@
}
conn_force_unsubscribe(conn);
- HA_SPIN_LOCK(OTHER_LOCK, &idle_conns[tid].takeover_lock);
MT_LIST_DEL((struct mt_list *)&conn->list);
- HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[tid].takeover_lock);
pool_free(pool_head_connection, conn);
}
diff --git a/src/server.c b/src/server.c
index a6824f7..ac32e1c 100644
--- a/src/server.c
+++ b/src/server.c
@@ -5193,32 +5193,41 @@
return task;
}
+/* Move toremove_nb connections from idle_list to toremove_list, -1 means
+ * moving them all.
+ * Returns the number of connections moved.
+ */
+static int srv_migrate_conns_to_remove(struct mt_list *idle_list, struct mt_list *toremove_list, int toremove_nb)
+{
+ struct mt_list *elt1, elt2;
+ struct connection *conn;
+ int i = 0;
+
+ mt_list_for_each_entry_safe(conn, idle_list, list, elt1, elt2) {
+ if (toremove_nb != -1 && i >= toremove_nb)
+ break;
+ MT_LIST_DEL_SAFE_NOINIT(elt1);
+ MT_LIST_ADDQ_NOCHECK(toremove_list, &conn->list);
+ i++;
+ }
+ return i;
+}
/* cleanup connections for a given server
* might be useful when going on forced maintenance or live changing ip/port
*/
static void srv_cleanup_connections(struct server *srv)
{
- struct connection *conn;
int did_remove;
int i;
- int j;
/* check all threads starting with ours */
HA_SPIN_LOCK(OTHER_LOCK, &idle_conn_srv_lock);
for (i = tid;;) {
did_remove = 0;
- HA_SPIN_LOCK(OTHER_LOCK, &idle_conns[i].takeover_lock);
- for (j = 0; j < srv->curr_idle_conns; j++) {
- conn = MT_LIST_POP(&srv->idle_conns[i], struct connection *, list);
- if (!conn)
- conn = MT_LIST_POP(&srv->safe_conns[i],
- struct connection *, list);
- if (!conn)
- break;
+ if (srv_migrate_conns_to_remove(&srv->idle_conns[i], &idle_conns[i].toremove_conns, -1) > 0)
did_remove = 1;
- MT_LIST_ADDQ(&idle_conns[i].toremove_conns, (struct mt_list *)&conn->list);
- }
- HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[i].takeover_lock);
+ if (srv_migrate_conns_to_remove(&srv->safe_conns[i], &idle_conns[i].toremove_conns, -1) > 0)
+ did_remove = 1;
if (did_remove)
task_wakeup(idle_conns[i].cleanup_task, TASK_WOKEN_OTHER);
@@ -5287,18 +5296,14 @@
max_conn = (exceed_conns * srv->curr_idle_thr[i]) /
curr_idle + 1;
- HA_SPIN_LOCK(OTHER_LOCK, &idle_conns[i].takeover_lock);
- for (j = 0; j < max_conn; j++) {
- struct connection *conn = MT_LIST_POP(&srv->idle_conns[i], struct connection *, list);
- if (!conn)
- conn = MT_LIST_POP(&srv->safe_conns[i],
- struct connection *, list);
- if (!conn)
- break;
+
+ j = srv_migrate_conns_to_remove(&srv->idle_conns[i], &idle_conns[i].toremove_conns, max_conn);
+ if (j > 0)
+ did_remove = 1;
+ if (max_conn - j > 0 &&
+ srv_migrate_conns_to_remove(&srv->safe_conns[i], &idle_conns[i].toremove_conns, max_conn - j) > 0)
did_remove = 1;
- MT_LIST_ADDQ(&idle_conns[i].toremove_conns, (struct mt_list *)&conn->list);
- }
- HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[i].takeover_lock);
+
if (did_remove && max_conn < srv->curr_idle_thr[i])
srv_is_empty = 0;
if (did_remove)