[ovs-dev] [PATCH 3/3] dpif-netdev: Destroy pmd threads only if pmd-cpu-mask changed.

[Ilya Maximets]

Since 5f2ccb1c0d3b ("dpif: Allow adding ukeys for same flow by
different pmds.") there is the possibility to reassign queues among
pmd threads without restarting them and deleting the megaflow cache.

So, reconfiguration can be performed without destroying of PMD threads
if pmd-cpu-mask not changed.

Reassignment of all rx queues done to achieve fair distribution.

Signed-off-by: Ilya Maximets <i.maxim...@samsung.com>
---
 lib/dpif-netdev.c | 62 +++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 42 insertions(+), 20 deletions(-)

diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index e62f5f6..8069163 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -2373,27 +2373,31 @@ dpif_netdev_operate(struct dpif *dpif, struct dpif_op 
**ops, size_t n_ops)
     }
 }
 
-/* Returns true if the configuration for rx queues or cpu mask
- * is changed. */
+/* Returns true if the configuration of rx queues changed. */
 static bool
-pmd_config_changed(const struct dp_netdev *dp, const char *cmask)
+pmd_n_rxq_changed(const struct dp_netdev *dp)
 {
     struct dp_netdev_port *port;
 
     CMAP_FOR_EACH (port, node, &dp->ports) {
-        struct netdev *netdev = port->netdev;
-        int requested_n_rxq = netdev_requested_n_rxq(netdev);
-        if (netdev_is_pmd(netdev)
+        int requested_n_rxq = netdev_requested_n_rxq(port->netdev);
+        if (netdev_is_pmd(port->netdev)
             && port->latest_requested_n_rxq != requested_n_rxq) {
             return true;
         }
     }
+    return false;
+}
 
+/* Returns true if cpu mask changed. */
+static bool
+pmd_cpu_mask_changed(const struct dp_netdev *dp, const char *cmask)
+{
     if (dp->pmd_cmask != NULL && cmask != NULL) {
         return strcmp(dp->pmd_cmask, cmask);
-    } else {
-        return (dp->pmd_cmask != NULL || cmask != NULL);
     }
+
+    return (dp->pmd_cmask != NULL || cmask != NULL);
 }
 
 /* Resets pmd threads if the configuration for 'rxq's or cpu mask changes. */
@@ -2401,11 +2405,20 @@ static int
 dpif_netdev_pmd_set(struct dpif *dpif, const char *cmask)
 {
     struct dp_netdev *dp = get_dp_netdev(dpif);
+    bool cmask_changed = pmd_cpu_mask_changed(dp, cmask);
+    struct dp_netdev_port *port;
 
-    if (pmd_config_changed(dp, cmask)) {
-        struct dp_netdev_port *port;
+    if (cmask_changed || pmd_n_rxq_changed(dp)) {
+        if (cmask_changed) {
+            dp_netdev_destroy_all_pmds(dp);
+        } else {
+            struct dp_netdev_pmd_thread *pmd;
 
-        dp_netdev_destroy_all_pmds(dp);
+            CMAP_FOR_EACH (pmd, node, &dp->poll_threads) {
+                dp_netdev_pmd_clear_poll_list(pmd);
+                dp_netdev_reload_pmd__(pmd);
+            }
+        }
 
         CMAP_FOR_EACH (port, node, &dp->ports) {
             struct netdev *netdev = port->netdev;
@@ -2439,15 +2452,24 @@ dpif_netdev_pmd_set(struct dpif *dpif, const char 
*cmask)
                 }
             }
         }
-        /* Reconfigures the cpu mask. */
-        ovs_numa_set_cpu_mask(cmask);
-        free(dp->pmd_cmask);
-        dp->pmd_cmask = cmask ? xstrdup(cmask) : NULL;
-
-        /* Restores the non-pmd. */
-        dp_netdev_set_nonpmd(dp);
-        /* Restores all pmd threads. */
-        dp_netdev_reset_pmd_threads(dp);
+
+        if (cmask_changed) {
+            /* Reconfigures the cpu mask. */
+            ovs_numa_set_cpu_mask(cmask);
+            free(dp->pmd_cmask);
+            dp->pmd_cmask = cmask ? xstrdup(cmask) : NULL;
+
+            /* Restores the non-pmd. */
+            dp_netdev_set_nonpmd(dp);
+            /* Restores all pmd threads. */
+            dp_netdev_reset_pmd_threads(dp);
+        } else {
+            CMAP_FOR_EACH (port, node, &dp->ports) {
+                if (netdev_is_pmd(port->netdev)) {
+                    dp_netdev_add_port_to_pmds(dp, port);
+                }
+            }
+        }
     }
 
     return 0;
-- 
2.5.0

_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev