[ovs-dev] [PATCH v4 2/3] dpif-netdev: Add better debug on auto load balance parameters.

[Kevin Traynor]

Previously if auto load balance was disabled, updates to parameters
did not get logged.

Add logs so that if there are any changes to the parameters, the change
is shown as well as the current enabled/disabled state of auto load balance.

Also, show the parameters when auto load balance is changed to be enabled.

e.g.
|dpif_netdev|INFO|PMD auto load balance pmd load threshold changed to 70%
|dpif_netdev|INFO|PMD auto load balance is disabled

Signed-off-by: Kevin Traynor <ktraynor at redhat.com>
---
 lib/dpif-netdev.c | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index eb19a3afc..9c24b58d2 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -4202,9 +4202,10 @@ dpif_netdev_operate(struct dpif *dpif, struct dpif_op **ops, size_t n_ops,
 /* Enable or Disable PMD auto load balancing. */
 static void
-set_pmd_auto_lb(struct dp_netdev *dp)
+set_pmd_auto_lb(struct dp_netdev *dp, bool always_log)
 {
     unsigned int cnt = 0;
     struct dp_netdev_pmd_thread *pmd;
     struct pmd_auto_lb *pmd_alb = &dp->pmd_alb;
+    uint8_t rebalance_load_thresh;
 
     bool enable_alb = false;
@@ -4233,10 +4234,16 @@ set_pmd_auto_lb(struct dp_netdev *dp)
                     pmd_alb->auto_lb_requested;
 
-    if (pmd_alb->is_enabled != enable_alb) {
+    if (pmd_alb->is_enabled != enable_alb || always_log) {
         pmd_alb->is_enabled = enable_alb;
         if (pmd_alb->is_enabled) {
+            atomic_read_relaxed(&pmd_alb->rebalance_load_thresh,
+                                &rebalance_load_thresh);
             VLOG_INFO("PMD auto load balance is enabled "
-                      "(with rebalance interval:%"PRIu64" msec)",
-                       pmd_alb->rebalance_intvl);
+                      "interval %"PRIu64" mins, "
+                      "pmd load threshold %"PRIu8"%%, "
+                      "improvement threshold %"PRIu8"%%",
+                       pmd_alb->rebalance_intvl / MIN_TO_MSEC,
+                       rebalance_load_thresh,
+                       pmd_alb->rebalance_improve_thresh);
         } else {
             pmd_alb->rebalance_poll_timer = 0;
@@ -4244,5 +4251,4 @@ set_pmd_auto_lb(struct dp_netdev *dp)
         }
     }
-
 }
 
@@ -4264,4 +4270,5 @@ dpif_netdev_set_config(struct dpif *dpif, const struct smap *other_config)
     uint8_t rebalance_load, cur_rebalance_load;
     uint8_t rebalance_improve;
+    bool log_autolb = false;
 
     tx_flush_interval = smap_get_int(other_config, "tx-flush-interval",
@@ -4349,4 +4356,7 @@ dpif_netdev_set_config(struct dpif *dpif, const struct smap *other_config)
     if (pmd_alb->rebalance_intvl != rebalance_intvl) {
         pmd_alb->rebalance_intvl = rebalance_intvl;
+        VLOG_INFO("PMD auto load balance interval set to "
+                  "%"PRIu64" mins\n", rebalance_intvl / MIN_TO_MSEC);
+        log_autolb = true;
     }
 
@@ -4358,4 +4368,7 @@ dpif_netdev_set_config(struct dpif *dpif, const struct smap *other_config)
     if (rebalance_improve != pmd_alb->rebalance_improve_thresh) {
         pmd_alb->rebalance_improve_thresh = rebalance_improve;
+        VLOG_INFO("PMD auto load balance improvement threshold set to "
+                  "%"PRIu8"%%\n", rebalance_improve);
+        log_autolb = true;
     }
 
@@ -4369,6 +4382,9 @@ dpif_netdev_set_config(struct dpif *dpif, const struct smap *other_config)
         atomic_store_relaxed(&pmd_alb->rebalance_load_thresh,
                              rebalance_load);
+        VLOG_INFO("PMD auto load balance pmd load threshold set to "
+                "%"PRIu8"%%\n", rebalance_load);
+        log_autolb = true;
     }
-    set_pmd_auto_lb(dp);
+    set_pmd_auto_lb(dp, log_autolb);
     return 0;
 }
@@ -5454,5 +5470,5 @@ reconfigure_datapath(struct dp_netdev *dp)
 
     /* Check if PMD Auto LB is to be enabled */
-    set_pmd_auto_lb(dp);
+    set_pmd_auto_lb(dp, false);
 }
 
-- 
2.26.2