utilities: Add revalidator measurement script and needed USDT probes.

This patch adds a Python script that can be used to analyze the
revalidator runs by providing statistics (including some real time
graphs).

The USDT events can also be captured to a file and used for
later offline analysis.

The following blog explains the Open vSwitch revalidator
implementation and how this tool can help you understand what is
happening in your system.

https://developers.redhat.com/articles/2022/10/19/open-vswitch-revalidator-process-explained

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Adrian Moreno <amorenoz@redhat.com>
Acked-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c
index 442141ccd..31ac02d11 100644
--- a/ofproto/ofproto-dpif-upcall.c
+++ b/ofproto/ofproto-dpif-upcall.c
@@ -42,6 +42,7 @@
 #include "seq.h"
 #include "tunnel.h"
 #include "unixctl.h"
+#include "openvswitch/usdt-probes.h"
 #include "openvswitch/vlog.h"
 #include "lib/netdev-provider.h"
 
@@ -978,6 +979,7 @@ udpif_revalidator(void *arg)
                 terse_dump = udpif_use_ufid(udpif);
                 udpif->dump = dpif_flow_dump_create(udpif->dpif, terse_dump,
                                                     NULL);
+                OVS_USDT_PROBE(udpif_revalidator, start_dump, udpif, n_flows);
             }
         }
 
@@ -1029,6 +1031,9 @@ udpif_revalidator(void *arg)
                           duration);
             }
 
+            OVS_USDT_PROBE(udpif_revalidator, sweep_done, udpif, n_flows,
+                           MIN(ofproto_max_idle, ofproto_max_revalidator));
+
             poll_timer_wait_until(start_time + MIN(ofproto_max_idle,
                                                    ofproto_max_revalidator));
             seq_wait(udpif->reval_seq, last_reval_seq);
@@ -2239,6 +2244,9 @@ revalidate_ukey__(struct udpif *udpif, const struct udpif_key *ukey,
         .wc = &wc,
     };
 
+    OVS_USDT_PROBE(revalidate_ukey__, entry, udpif, ukey, tcp_flags,
+                   odp_actions, recircs, xcache);
+
     result = UKEY_DELETE;
     xoutp = NULL;
     netflow = NULL;
@@ -2302,6 +2310,9 @@ exit:
         netflow_flow_clear(netflow, &ctx.flow);
     }
     xlate_out_uninit(xoutp);
+
+    OVS_USDT_PROBE(revalidate_ukey__, exit, udpif, ukey, result);
+
     return result;
 }