From 3fe8050596e3cff28c007b5d7c1ec9c461849995 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Mon, 20 Jun 2011 14:21:06 -0700
Subject: [PATCH] bridge: Enable system stats only if turned on in the
 database.

Most hypervisors have no use for this column, so populating it just wastes
CPU time.  It can still be enabled explicitly via other-config.

CC: Peter Balland <peter@nicira.com>
CC: David Tsai <dtsai@nicira.com>
Bug #5961.
NIC-397.
---
 vswitchd/bridge.c          | 21 ++++++++++++++++++++-
 vswitchd/vswitch.ovsschema |  6 ++++--
 vswitchd/vswitch.xml       | 18 ++++++++++++++++++
 3 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 3a9cfa9d..d0a5764d 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -1291,6 +1291,23 @@ iface_refresh_stats(struct iface *iface)
 #undef IFACE_STATS
 }
 
+static bool
+enable_system_stats(const struct ovsrec_open_vswitch *cfg)
+{
+    const char *enable;
+
+    /* Use other-config:enable-system-stats by preference. */
+    enable = get_ovsrec_key_value(&cfg->header_,
+                                  &ovsrec_open_vswitch_col_other_config,
+                                  "enable-statistics");
+    if (enable) {
+        return !strcmp(enable, "true");
+    }
+
+    /* Disable by default. */
+    return false;
+}
+
 static void
 refresh_system_stats(const struct ovsrec_open_vswitch *cfg)
 {
@@ -1298,7 +1315,9 @@ refresh_system_stats(const struct ovsrec_open_vswitch *cfg)
     struct shash stats;
 
     shash_init(&stats);
-    get_system_stats(&stats);
+    if (enable_system_stats(cfg)) {
+        get_system_stats(&stats);
+    }
 
     ovsdb_datum_from_shash(&datum, &stats);
     ovsdb_idl_txn_write(&cfg->header_, &ovsrec_open_vswitch_col_statistics,
diff --git a/vswitchd/vswitch.ovsschema b/vswitchd/vswitch.ovsschema
index dee2a045..315affcb 100644
--- a/vswitchd/vswitch.ovsschema
+++ b/vswitchd/vswitch.ovsschema
@@ -1,6 +1,6 @@
 {"name": "Open_vSwitch",
- "version": "5.0.1",
- "cksum": "246745439 14434",
+ "version": "5.1.0",
+ "cksum": "154459795 14545",
  "tables": {
    "Open_vSwitch": {
      "columns": {
@@ -16,6 +16,8 @@
          "type": {"key": {"type": "uuid",
                           "refTable": "SSL"},
                   "min": 0, "max": 1}},
+       "other_config": {
+         "type": {"key": "string", "value": "string", "min": 0, "max": "unlimited"}},
        "external_ids": {
          "type": {"key": "string", "value": "string",
                   "min": 0, "max": "unlimited"}},
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index 3be4ccba..e399eeea 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -25,6 +25,19 @@
         SSL used globally by the daemon.
       </column>
 
+      <column name="other_config">
+        Key-value pairs for configuring rarely used Open vSwitch features.  The
+        currently defined key-value pairs are:
+        <dl>
+          <dt><code>enable-statistics</code></dt>
+          <dd>
+            Set to <code>true</code> to enable populating the <ref
+            column="statistics"/> column or <code>false</code> (the default)
+            disable populating it.
+          </dd>
+        </dl>
+      </column>
+
       <column name="external_ids">
         Key-value pairs for use by external frameworks that integrate
         with Open vSwitch, rather than by Open vSwitch itself.  System
@@ -75,6 +88,11 @@
           apply to a platform are omitted.
         </p>
 
+        <p>
+          Statistics are disabled unless <ref column="other-config"
+          key="enable-statistics"/> is set to <code>true</code>.
+        </p>
+
         <dl>
           <dt><code>cpu</code></dt>
           <dd>
-- 
2.30.2