dpif-netdev: Implement batched flow dumping.

Previously, flows were retrieved one by one when dumping flows for datapaths of type 'netdev'. This increased contention for the dump's mutex, negatively affecting revalidator performance. This patch retrieves batches of flows when dumping flows for datapaths of type 'netdev'. Signed-off-by: Ryan Wilson <[email protected]> [[email protected] relaxed max_flows restriction] Signed-off-by: Ben Pfaff <[email protected]>
water0615 · Jun 25, 2014 · 8bb113d · 8bb113d
1 parent 4eb58d3
commit 8bb113d
Showing 1 changed file with 56 additions and 47 deletions.
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
@@ -69,6 +69,7 @@ VLOG_DEFINE_THIS_MODULE(dpif_netdev);
 /* By default, choose a priority in the middle. */
 #define NETDEV_RULE_PRIORITY 0x8000
 
+#define FLOW_DUMP_MAX_BATCH 50
 #define NR_THREADS 1
 /* Use per thread recirc_depth to prevent recirculation loop. */
 #define MAX_RECIRC_DEPTH 5
@@ -1438,8 +1439,8 @@ dpif_netdev_flow_dump_destroy(struct dpif_flow_dump *dump_)
 struct dpif_netdev_flow_dump_thread {
     struct dpif_flow_dump_thread up;
     struct dpif_netdev_flow_dump *dump;
-    struct odputil_keybuf keybuf;
-    struct odputil_keybuf maskbuf;
+    struct odputil_keybuf keybuf[FLOW_DUMP_MAX_BATCH];
+    struct odputil_keybuf maskbuf[FLOW_DUMP_MAX_BATCH];
 };
 
 static struct dpif_netdev_flow_dump_thread *
@@ -1472,65 +1473,73 @@ dpif_netdev_flow_dump_thread_destroy(struct dpif_flow_dump_thread *thread_)
 /* XXX the caller must use 'actions' without quiescing */
 static int
 dpif_netdev_flow_dump_next(struct dpif_flow_dump_thread *thread_,
-                           struct dpif_flow *f, int max_flows OVS_UNUSED)
+                           struct dpif_flow *flows, int max_flows)
 {
     struct dpif_netdev_flow_dump_thread *thread
         = dpif_netdev_flow_dump_thread_cast(thread_);
     struct dpif_netdev_flow_dump *dump = thread->dump;
     struct dpif_netdev *dpif = dpif_netdev_cast(thread->up.dpif);
+    struct dp_netdev_flow *netdev_flows[FLOW_DUMP_MAX_BATCH];
     struct dp_netdev *dp = get_dp_netdev(&dpif->dpif);
-    struct dp_netdev_flow *netdev_flow;
-    struct flow_wildcards wc;
-    struct dp_netdev_actions *dp_actions;
-    struct ofpbuf buf;
-    int error;
+    int n_flows = 0;
+    int i;
 
     ovs_mutex_lock(&dump->mutex);
-    error = dump->status;
-    if (!error) {
-        struct hmap_node *node;
-
+    if (!dump->status) {
         fat_rwlock_rdlock(&dp->cls.rwlock);
-        node = hmap_at_position(&dp->flow_table, &dump->bucket, &dump->offset);
-        if (node) {
-            netdev_flow = CONTAINER_OF(node, struct dp_netdev_flow, node);
+        for (n_flows = 0; n_flows < MIN(max_flows, FLOW_DUMP_MAX_BATCH);
+             n_flows++) {
+            struct hmap_node *node;
+
+            node = hmap_at_position(&dp->flow_table, &dump->bucket,
+                                    &dump->offset);
+            if (!node) {
+                dump->status = EOF;
+                break;
+            }
+            netdev_flows[n_flows] = CONTAINER_OF(node, struct dp_netdev_flow,
+                                                 node);
         }
         fat_rwlock_unlock(&dp->cls.rwlock);
-        if (!node) {
-            dump->status = error = EOF;
-        }
     }
     ovs_mutex_unlock(&dump->mutex);
-    if (error) {
-        return 0;
-    }
-
-    minimask_expand(&netdev_flow->cr.match.mask, &wc);
-
-    /* Key. */
-    ofpbuf_use_stack(&buf, &thread->keybuf, sizeof thread->keybuf);
-    odp_flow_key_from_flow(&buf, &netdev_flow->flow, &wc.masks,
-                           netdev_flow->flow.in_port.odp_port, true);
-    f->key = ofpbuf_data(&buf);
-    f->key_len = ofpbuf_size(&buf);
-
-    /* Mask. */
-    ofpbuf_use_stack(&buf, &thread->maskbuf, sizeof thread->maskbuf);
-    odp_flow_key_from_mask(&buf, &wc.masks, &netdev_flow->flow,
-                           odp_to_u32(wc.masks.in_port.odp_port),
-                           SIZE_MAX, true);
-    f->mask = ofpbuf_data(&buf);
-    f->mask_len = ofpbuf_size(&buf);
-
-    /* Actions. */
-    dp_actions = dp_netdev_flow_get_actions(netdev_flow);
-    f->actions = dp_actions->actions;
-    f->actions_len = dp_actions->size;
-
-    /* Stats. */
-    get_dpif_flow_stats(netdev_flow, &f->stats);
 
-    return 1;
+    for (i = 0; i < n_flows; i++) {
+        struct odputil_keybuf *maskbuf = &thread->maskbuf[i];
+        struct odputil_keybuf *keybuf = &thread->keybuf[i];
+        struct dp_netdev_flow *netdev_flow = netdev_flows[i];
+        struct dpif_flow *f = &flows[i];
+        struct dp_netdev_actions *dp_actions;
+        struct flow_wildcards wc;
+        struct ofpbuf buf;
+
+        minimask_expand(&netdev_flow->cr.match.mask, &wc);
+
+        /* Key. */
+        ofpbuf_use_stack(&buf, keybuf, sizeof *keybuf);
+        odp_flow_key_from_flow(&buf, &netdev_flow->flow, &wc.masks,
+                               netdev_flow->flow.in_port.odp_port, true);
+        f->key = ofpbuf_data(&buf);
+        f->key_len = ofpbuf_size(&buf);
+
+        /* Mask. */
+        ofpbuf_use_stack(&buf, maskbuf, sizeof *maskbuf);
+        odp_flow_key_from_mask(&buf, &wc.masks, &netdev_flow->flow,
+                               odp_to_u32(wc.masks.in_port.odp_port),
+                               SIZE_MAX, true);
+        f->mask = ofpbuf_data(&buf);
+        f->mask_len = ofpbuf_size(&buf);
+
+        /* Actions. */
+        dp_actions = dp_netdev_flow_get_actions(netdev_flow);
+        f->actions = dp_actions->actions;
+        f->actions_len = dp_actions->size;
+
+        /* Stats. */
+        get_dpif_flow_stats(netdev_flow, &f->stats);
+    }
+
+    return n_flows;
 }
 
 static int