[ovs-dev,v4,2/4] revalidator: Gather packets-per-second rate of flows

Message ID 20180712072934.13001-3-sriharsha.basavapatna@broadcom.com
State New
Headers show
Series
  • Support dynamic rebalancing of offloaded flows
Related show

Commit Message

Sriharsha Basavapatna via dev July 12, 2018, 7:29 a.m.
This is the second patch in the patch-set to support dynamic rebalancing
of offloaded flows.

The packets-per-second (pps) rate for each flow is computed in the context
of revalidator threads when the flow stats are retrieved. The pps-rate is
computed only after a flow is revalidated and is not scheduled for
deletion. The parameters used to compute pps and the pps itself are saved
in udpif_key since they need to be persisted across iterations of
rebalancing.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Co-authored-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Signed-off-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Reviewed-by: Sathya Perla <sathya.perla@broadcom.com>
---
 lib/dpif-provider.h           |   1 +
 ofproto/ofproto-dpif-upcall.c | 152 ++++++++++++++++++++++++++++++++++
 2 files changed, 153 insertions(+)

Patch

diff --git a/lib/dpif-provider.h b/lib/dpif-provider.h
index 62b3598ac..cc6571b28 100644
--- a/lib/dpif-provider.h
+++ b/lib/dpif-provider.h
@@ -39,6 +39,7 @@  struct dpif {
     char *full_name;
     uint8_t netflow_engine_type;
     uint8_t netflow_engine_id;
+    long long int current_ms;
 };
 
 void dpif_init(struct dpif *, const struct dpif_class *, const char *name,
diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c
index 85f579251..355be9f39 100644
--- a/ofproto/ofproto-dpif-upcall.c
+++ b/ofproto/ofproto-dpif-upcall.c
@@ -42,6 +42,8 @@ 
 #include "tunnel.h"
 #include "unixctl.h"
 #include "openvswitch/vlog.h"
+#include "lib/dpif-provider.h"
+#include "lib/netdev-provider.h"
 
 #define MAX_QUEUE_LENGTH 512
 #define UPCALL_MAX_BATCH 64
@@ -304,6 +306,16 @@  struct udpif_key {
 
     uint32_t key_recirc_id;   /* Non-zero if reference is held by the ukey. */
     struct recirc_refs recircs;  /* Action recirc IDs with references held. */
+
+#define OFFL_REBAL_INTVL_MSEC  3000	/* dynamic offload rebalance freq */
+    struct netdev *in_netdev;		/* in_odp_port's netdev */
+    struct netdev *out_netdev;		/* out_odp_port's netdev */
+    struct netdev *tunnel_netdev;	/* tunnel netdev */
+    bool offloaded;			/* True if flow is offloaded */
+    float flow_pps_rate;		/* Packets-Per-Second rate */
+    long long int flow_time;		/* last pps update time */
+    uint64_t flow_packets;		/* #pkts seen in interval */
+    uint64_t flow_backlog_packets;	/* prev-mode #pkts (offl or kernel) */
 };
 
 /* Datapath operation with optional ukey attached. */
@@ -1667,6 +1679,11 @@  ukey_create__(const struct nlattr *key, size_t key_len,
     ukey->stats.used = used;
     ukey->xcache = NULL;
 
+    ukey->offloaded = false;
+    ukey->flow_time = 0;
+    ukey->in_netdev = ukey->out_netdev = ukey->tunnel_netdev = NULL;
+    ukey->flow_packets = ukey->flow_backlog_packets = 0;
+
     ukey->key_recirc_id = key_recirc_id;
     recirc_refs_init(&ukey->recircs);
     if (xout) {
@@ -2442,6 +2459,137 @@  reval_op_init(struct ukey_op *op, enum reval_result result,
     }
 }
 
+/*
+ * Given a dpif_flow, get its input and output ports (netdevs) by parsing
+ * the flow keys and actions. Save them in udpif_key.
+ */
+static void
+dpif_flow_to_netdevs(struct dpif *dpif, struct udpif_key *ukey,
+                     struct dpif_flow *f)
+{
+    const struct dpif_class *dpif_class = dpif->dpif_class;
+    odp_port_t out_port = ODPP_NONE;
+    odp_port_t in_port = ODPP_NONE;
+    const struct nlattr *a;
+    const struct nlattr *k;
+    bool forward = false;
+    unsigned int left;
+
+    ukey->in_netdev = NULL;
+    ukey->out_netdev = NULL;
+
+    /* Capture the output port */
+    NL_ATTR_FOR_EACH (a, left, f->actions, f->actions_len) {
+        enum ovs_action_attr type = nl_attr_type(a);
+        if (type == OVS_ACTION_ATTR_OUTPUT) {
+            /* Only unicast is supported */
+            if (forward) {
+                ukey->out_netdev = NULL;
+                ukey->in_netdev = NULL;
+                return;
+            }
+
+            forward = true;
+            out_port = nl_attr_get_odp_port(a);
+            ukey->out_netdev = netdev_ports_get(out_port, dpif_class);
+            break;
+        }
+    }
+
+    /* Now find the input port */
+    NL_ATTR_FOR_EACH (k, left, f->key, f->key_len) {
+        unsigned int type;
+        struct flow_tnl tnl;
+        enum odp_key_fitness res;
+
+        type = nl_attr_type(k);
+
+        switch (type) {
+        case OVS_KEY_ATTR_IN_PORT:
+            in_port = *(odp_port_t *)nl_attr_get(k);
+            ukey->in_netdev = netdev_ports_get(in_port, dpif_class);
+            break;
+        case OVS_KEY_ATTR_TUNNEL:
+            res = odp_tun_key_from_attr(k, &tnl);
+            if (res == ODP_FIT_ERROR) {
+                ukey->tunnel_netdev = NULL;
+                break;
+            }
+            ukey->tunnel_netdev = flow_get_tunnel_netdev(&tnl);
+            break;
+        default:
+            break;
+        }
+    }
+}
+
+/*
+ * Given a udpif_key and a corresponding dpif_flow, get its input and output
+ * ports (netdevs). The flow may not contain flow attributes if is a terse
+ * dump; read its attributes from the ukey and then parse the flow to get
+ * the port info.
+ */
+static void
+udpif_key_to_flow_netdevs(struct udpif *udpif, struct udpif_key *ukey,
+                          struct dpif_flow *f)
+{
+    const struct nlattr *actions;
+    size_t actions_len;
+
+    /* Read flow keys and masks from ukey */
+    f->key = ukey->key;
+    f->key_len = ukey->key_len;
+    f->mask = ukey->mask;
+    f->mask_len = ukey->mask_len;
+
+    /* Read actions from ukey */
+    ukey_get_actions(ukey, &actions, &actions_len);
+    f->actions = actions;
+    f->actions_len = actions_len;
+
+    /* Get netdev info for the flow now */
+    dpif_flow_to_netdevs(udpif->dpif, ukey, f);
+}
+
+static float
+udpif_flow_packet_delta(struct udpif_key *ukey, const struct dpif_flow *f)
+{
+    return ((float)((f->stats.n_packets + ukey->flow_backlog_packets) -
+                    ukey->flow_packets));
+}
+
+static long long int
+udpif_flow_time_delta(struct udpif *udpif, struct udpif_key *ukey)
+{
+    return (udpif->dpif->current_ms - ukey->flow_time) / 1000;
+}
+
+/* Gather pps-rate for the given dpif_flow and save it in its ukey */
+static void
+udpif_update_flow_pps(struct udpif *udpif, struct udpif_key *ukey,
+                      const struct dpif_flow *f)
+{
+    struct dpif_flow tmp_flow;
+    float pps;
+
+    ukey->offloaded = f->attrs.offloaded;
+    udpif_key_to_flow_netdevs(udpif, ukey, &tmp_flow);
+
+    if ((udpif->dpif->current_ms - ukey->flow_time) <= OFFL_REBAL_INTVL_MSEC) {
+        return;
+    }
+    if ((f->stats.n_packets + ukey->flow_backlog_packets) <
+        ukey->flow_packets) {
+        return;
+    }
+
+    pps = udpif_flow_packet_delta(ukey, f) /
+                    udpif_flow_time_delta(udpif, ukey);
+    ukey->flow_pps_rate = pps;
+    ukey->flow_packets = ukey->flow_backlog_packets + f->stats.n_packets;
+    ukey->flow_time = udpif->dpif->current_ms;
+}
+
 static void
 revalidate(struct revalidator *revalidator)
 {
@@ -2550,6 +2698,10 @@  revalidate(struct revalidator *revalidator)
             }
             ukey->dump_seq = dump_seq;
 
+            if (result != UKEY_DELETE) {
+                udpif_update_flow_pps(udpif, ukey, f);
+            }
+
             if (result != UKEY_KEEP) {
                 /* Takes ownership of 'recircs'. */
                 reval_op_init(&ops[n_ops++], result, udpif, ukey, &recircs,