[ovs-dev,v7,2/3] revalidator: Gather packets-per-second rate of flows

Message ID 20180927064827.26256-3-sriharsha.basavapatna@broadcom.com
State New
Headers show
Series
  • Support dynamic rebalancing of offloaded flows
Related show

Commit Message

Sriharsha Basavapatna via dev Sept. 27, 2018, 6:48 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 | 51 +++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

Patch

diff --git a/lib/dpif-provider.h b/lib/dpif-provider.h
index 873b6e3d4..7a71f5c0a 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 62222079f..a372d6252 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 +306,13 @@  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 */
+    bool offloaded;			/* True if flow is offloaded */
+    uint64_t 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 +1676,10 @@  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->flow_packets = ukey->flow_backlog_packets = 0;
+
     ukey->key_recirc_id = key_recirc_id;
     recirc_refs_init(&ukey->recircs);
     if (xout) {
@@ -2442,6 +2455,39 @@  reval_op_init(struct ukey_op *op, enum reval_result result,
     }
 }
 
+static uint64_t
+udpif_flow_packet_delta(struct udpif_key *ukey, const struct dpif_flow *f)
+{
+    return 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)
+{
+    uint64_t pps;
+
+    /* Update pps-rate only when we are close to rebalance interval */
+    if (udpif->dpif->current_ms - ukey->flow_time < OFFL_REBAL_INTVL_MSEC) {
+        return;
+    }
+
+    ukey->offloaded = f->attrs.offloaded;
+    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 +2596,11 @@  revalidate(struct revalidator *revalidator)
             }
             ukey->dump_seq = dump_seq;
 
+            if (netdev_is_offload_rebalance_policy_enabled() &&
+                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,