dpif-linux: collect and display mega flow mask stats

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

6 files changed, 51 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index f6e2dafdf..50f20ad28 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,8 @@ Post-v2.0.0
    - ovs-vswitchd.conf.db.5 man page will contain graphviz/dot
      diagram only if graphviz package was installed at the build time.
    - Support for Linux kernels up to 3.11
+   - ovs-dpctl:
+     The "show" command also displays mega flow mask stats.
 
 
 v2.0.0 - 15 Oct 2013
diff --git a/lib/dpif-linux.c b/lib/dpif-linux.c
index 6f75f57e8..42958d3fc 100644
--- a/lib/dpif-linux.c
+++ b/lib/dpif-linux.c
@@ -74,6 +74,8 @@ struct dpif_linux_dp {
     const char *name;                  /* OVS_DP_ATTR_NAME. */
     const uint32_t *upcall_pid;        /* OVS_DP_UPCALL_PID. */
     struct ovs_dp_stats stats;         /* OVS_DP_ATTR_STATS. */
+    struct ovs_dp_megaflow_stats megaflow_stats;
+                                       /* OVS_DP_ATTR_MEGAFLOW_STATS.*/
 };
 
 static void dpif_linux_dp_init(struct dpif_linux_dp *);
@@ -411,6 +413,8 @@ dpif_linux_get_stats(const struct dpif *dpif_, struct dpif_dp_stats *stats)
         stats->n_missed = dp.stats.n_missed;
         stats->n_lost   = dp.stats.n_lost;
         stats->n_flows  = dp.stats.n_flows;
+        stats->n_masks  = dp.megaflow_stats.n_masks;
+        stats->n_mask_hit  = dp.megaflow_stats.n_mask_hit;
         ofpbuf_delete(buf);
     }
     return error;
@@ -1770,6 +1774,9 @@ dpif_linux_dp_from_ofpbuf(struct dpif_linux_dp *dp, const struct ofpbuf *buf)
         [OVS_DP_ATTR_NAME] = { .type = NL_A_STRING, .max_len = IFNAMSIZ },
         [OVS_DP_ATTR_STATS] = { NL_POLICY_FOR(struct ovs_dp_stats),
                                 .optional = true },
+        [OVS_DP_ATTR_MEGAFLOW_STATS] = {
+                        NL_POLICY_FOR(struct ovs_dp_megaflow_stats),
+                        .optional = true },
     };
 
     struct nlattr *a[ARRAY_SIZE(ovs_datapath_policy)];
@@ -1801,6 +1808,13 @@ dpif_linux_dp_from_ofpbuf(struct dpif_linux_dp *dp, const struct ofpbuf *buf)
                sizeof dp->stats);
     }
 
+    if (a[OVS_DP_ATTR_MEGAFLOW_STATS]) {
+        /* Can't use structure assignment because Netlink doesn't ensure
+         * sufficient alignment for 64-bit members. */
+        memcpy(&dp->megaflow_stats, nl_attr_get(a[OVS_DP_ATTR_MEGAFLOW_STATS]),
+               sizeof dp->megaflow_stats);
+    }
+
     return 0;
 }
 
@@ -1833,6 +1847,8 @@ static void
 dpif_linux_dp_init(struct dpif_linux_dp *dp)
 {
     memset(dp, 0, sizeof *dp);
+    dp->megaflow_stats.n_masks = UINT32_MAX;
+    dp->megaflow_stats.n_mask_hit = UINT64_MAX;
 }
 
 static void
@@ -1871,11 +1887,11 @@ dpif_linux_dp_transact(const struct dpif_linux_dp *request,
     ofpbuf_delete(request_buf);
 
     if (reply) {
+        dpif_linux_dp_init(reply);
         if (!error) {
             error = dpif_linux_dp_from_ofpbuf(reply, *bufp);
         }
         if (error) {
-            dpif_linux_dp_init(reply);
             ofpbuf_delete(*bufp);
             *bufp = NULL;
         }
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 0f6a71c74..370691ebd 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -394,6 +394,8 @@ dpif_netdev_get_stats(const struct dpif *dpif, struct dpif_dp_stats *stats)
     stats->n_hit = dp->n_hit;
     stats->n_missed = dp->n_missed;
     stats->n_lost = dp->n_lost;
+    stats->n_masks = UINT64_MAX;
+    stats->n_mask_hit = UINT64_MAX;
     ovs_mutex_unlock(&dp_netdev_mutex);
 
     return 0;
diff --git a/lib/dpif.h b/lib/dpif.h
index 8996c0a6a..ab69c1ce6 100644
--- a/lib/dpif.h
+++ b/lib/dpif.h
@@ -387,6 +387,9 @@ struct dpif_dp_stats {
     uint64_t n_missed;          /* Number of flow table misses. */
     uint64_t n_lost;            /* Number of misses not sent to userspace. */
     uint64_t n_flows;           /* Number of flows present. */
+    uint64_t n_masks;           /* Number of mega flow masks. */
+    uint64_t n_mask_hit;        /* Number of mega flow masks visited for
+                                   flow table matches. */
 };
 int dpif_get_dp_stats(const struct dpif *, struct dpif_dp_stats *);
 
diff --git a/utilities/ovs-dpctl.8.in b/utilities/ovs-dpctl.8.in
index 35d1be590..5a0dd7064 100644
--- a/utilities/ovs-dpctl.8.in
+++ b/utilities/ovs-dpctl.8.in
@@ -101,6 +101,25 @@ port is identified as port 0.)  If \fB\-s\fR or \fB\-\-statistics\fR
 is specified, then packet and byte counters are also printed for each
 port.
 .IP
+The datapath numbers consists of flow stats and mega flow mask stats.
+.IP
+The "lookups" row displays three stats related to flow lookup triggered
+by processing incoming packets in the datapath. "hit" displays number
+of packets matches existing flows. "missed" displays the number of
+packets not matching any existing flow and require user space processing.
+"lost" displays number of packets destined for user space process but
+subsequently dropped before reaching userspace. The sum of "hit" and "miss"
+equals to the total number of packets datapath processed.
+.IP
+The "flows" row displays the number of flows in datapath.
+.IP
+The "masks" row displays the mega flow mask stats. This row is omitted
+for datapath not implementing mega flow. "hit" displays the total number
+of masks visited for matching incoming packets. "total" displays number of
+masks in the datapath. "hit/pkt" displays the average number of masks
+visited per packet; the ratio between "hit" and total number of
+packets processed by the datapath".
+.IP
 If one or more datapaths are specified, information on only those
 datapaths are displayed.  Otherwise, \fBovs\-dpctl\fR displays information
 about all configured datapaths.
diff --git a/utilities/ovs-dpctl.c b/utilities/ovs-dpctl.c
index e11e102e3..78475e70c 100644
--- a/utilities/ovs-dpctl.c
+++ b/utilities/ovs-dpctl.c
@@ -563,7 +563,15 @@ show_dpif(struct dpif *dpif)
         printf("\tlookups: hit:%"PRIu64" missed:%"PRIu64" lost:%"PRIu64"\n"
                "\tflows: %"PRIu64"\n",
                stats.n_hit, stats.n_missed, stats.n_lost, stats.n_flows);
+        if (stats.n_masks != UINT64_MAX) {
+            uint64_t n_pkts = stats.n_hit + stats.n_missed;
+            double avg = n_pkts ? (double) stats.n_mask_hit / n_pkts : 0.0;
+
+            printf("\tmasks: hit:%"PRIu64" total:%"PRIu64" hit/pkt:%.2f\n",
+                   stats.n_mask_hit, stats.n_masks, avg);
+        }
     }
+
     DPIF_PORT_FOR_EACH (&dpif_port, &dump, dpif) {
         printf("\tport %u: %s", dpif_port.port_no, dpif_port.name);