From 62ab5594c20cc815592562af69abb5b8ebe85d55 Mon Sep 17 00:00:00 2001
From: Christophe Fontaine <cfontain@redhat.com>
Date: Mon, 21 Dec 2020 13:10:31 +0000
Subject: dpif-netdev: Add parameters to configure PMD auto load balance.

Two important parts of how PMD auto load balance operates are how
loaded a core needs to be and how much improvement is estimated
before a PMD auto load balance can trigger.

Previously they were hardcoded to 95% loaded and 25% variance
improvement.

These default values may not be suitable for all use cases and
we may want to use a more (or less) aggressive rebalance, either
on the pmd load threshold or on the minimum variance improvement
threshold.

The defaults are not changed, but "pmd-auto-lb-load-threshold" and
"pmd-auto-lb-improvement-threshold" parameters are added to override
the defaults.

$ ovs-vsctl set open_vswitch . other_config:pmd-auto-lb-load-threshold="70"
$ ovs-vsctl set open_vswitch . other_config:pmd-auto-lb-improvement-threshold="20"

Signed-off-by: Christophe Fontaine <cfontain@redhat.com>
Co-Authored-by: Kevin Traynor <ktraynor@redhat.com>
Signed-off-by: Kevin Traynor <ktraynor@redhat.com>
Acked-by: David Marchand <david.marchand@redhat.com>
Acked-by: Ian Stokes <ian.stokes@intel.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
---
 vswitchd/vswitch.xml | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

(limited to 'vswitchd')

diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml
index fee54b0fa..5b2a174ab 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -653,8 +653,9 @@
               type='{"type": "boolean"}'>
         <p>
          Configures PMD Auto Load Balancing that allows automatic assignment of
-         RX queues to PMDs if any of PMDs is overloaded (i.e. processing cycles
-         > 95%).
+         RX queues to PMDs if any of PMDs is overloaded (i.e. a processing
+         cycles >
+         <ref column="other_config" key="pmd-auto-lb-load-threshold"/>).
         </p>
         <p>
          It uses current scheme of cycle based assignment of RX queues that
@@ -690,6 +691,32 @@
          once in few hours or a day or a week.
         </p>
       </column>
+      <column name="other_config" key="pmd-auto-lb-load-threshold"
+              type='{"type": "integer", "minInteger": 0, "maxInteger": 100}'>
+        <p>
+         Specifies the minimum PMD thread load threshold (% of used cycles) of
+         any non-isolated PMD threads when a PMD Auto Load Balance may be
+         triggered.
+        </p>
+        <p>
+         The default value is <code>95%</code>.
+        </p>
+      </column>
+      <column name="other_config" key="pmd-auto-lb-improvement-threshold"
+              type='{"type": "integer", "minInteger": 0, "maxInteger": 100}'>
+        <p>
+         Specifies the minimum evaluated % improvement in load distribution
+         across the non-isolated PMD threads that will allow a PMD Auto Load
+         Balance to occur.
+        </p>
+        <p>
+         Note, setting this parameter to 0 will always allow an auto load
+         balance to occur regardless of estimated improvement or not.
+        </p>
+        <p>
+         The default value is <code>25%</code>.
+        </p>
+      </column>
       <column name="other_config" key="userspace-tso-enable"
               type='{"type": "boolean"}'>
         <p>
-- 
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