Changeset 1960910

Timestamp:

01/08/15 18:36:44 (6 years ago)

Author:

Richard Sanger <rsangerarj@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

9b533c6

Parents:

d7fd648

Message:

Add support to detect link status changes in DPDK.
This is useful to ensure the link speed is correct, given that
we generate packet timestamps based on this.

File:

• lib/format_dpdk.c (modified) (5 diffs)

lib/format_dpdk.c

@@ -911 +911 @@
                 },
         },
+        .intr_conf = {
+                .lsc = 1
+        }
 };
 
@@ -966 +969 @@
 };
 
+/**
+ * A callback for a link state change (LSC).
+ *
+ * Packets may be received before this notification. In fact the DPDK IGXBE
+ * driver likes to put a delay upto 5sec before sending this.
+ *
+ * We use this to ensure the link speed is correct for our timestamp
+ * calculations. Because packets might be received before the link up we still
+ * update this when the packet is received.
+ *
+ * @param port The DPDK port
+ * @param event The TYPE of event (expected to be RTE_ETH_EVENT_INTR_LSC)
+ * @param cb_arg The dpdk_format_data_t structure associated with the format
+ */
+static void dpdk_lsc_callback(uint8_t port, enum rte_eth_event_type event,
+                              void *cb_arg) {
+        struct dpdk_format_data_t * format_data = cb_arg;
+        struct rte_eth_link link_info;
+        assert(event == RTE_ETH_EVENT_INTR_LSC);
+        assert(port == format_data->port);
+
+        rte_eth_link_get_nowait(port, &link_info);
+
+        if (link_info.link_status)
+                format_data->link_speed = link_info.link_speed;
+        else
+                format_data->link_speed = 0;
+
+#if DEBUG
+        fprintf(stderr, "LSC - link status is %s %s speed=%d\n",
+                link_info.link_status ? "up" : "down",
+                (link_info.link_duplex == ETH_LINK_FULL_DUPLEX) ?
+                                          "full-duplex" : "half-duplex",
+                (int) link_info.link_speed);
+#endif
+
+        /* Turns out DPDK drivers might not come back up if the link speed
+         * changes. So we reset the autoneg procedure. This is very unsafe
+         * we have have threads reading packets and we stop the port. */
+#if 0
+        if (!link_info.link_status) {
+                int ret;
+                rte_eth_dev_stop(port);
+                ret = rte_eth_dev_start(port);
+                if (ret < 0) {
+                        fprintf(stderr, "Resetting the DPDK port failed : %s\n",
+                                strerror(-ret));
+                }
+        }
+#endif
+}
+
 /* Attach memory to the port and start the port or restart the port.
  */
@@ -1086 +1141 @@
         rte_eth_promiscuous_disable(format_data->port);
 
-    /* Wait for the link to come up */
-    rte_eth_link_get(format_data->port, &link_info);
+        /* Register a callback for link state changes */
+        ret = rte_eth_dev_callback_register(format_data->port,
+                                            RTE_ETH_EVENT_INTR_LSC,
+                                            dpdk_lsc_callback,
+                                            format_data);
+        /* If this fails it is not a show stopper */
+#if DEBUG
+        fprintf(stderr, "rte_eth_dev_callback_register failed %d : %s\n",
+                ret, strerror(-ret));
+#endif
+
+    /* Get the current link status */
+    rte_eth_link_get_nowait(format_data->port, &link_info);
     format_data->link_speed = link_info.link_speed;
 #if DEBUG
@@ -1245 +1311 @@
         }*/
 
-    /* Wait for the link to come up */
-    rte_eth_link_get(format_data->port, &link_info);
+    /* Register a callback for link state changes */
+    ret = rte_eth_dev_callback_register(format_data->port,
+                                        RTE_ETH_EVENT_INTR_LSC,
+                                        dpdk_lsc_callback,
+                                        format_data);
+    /* If this fails it is not a show stopper */
+#if DEBUG
+    fprintf(stderr, "rte_eth_dev_callback_register failed %d : %s\n",
+            ret, strerror(-ret));
+#endif
+
+    /* Get the current link status */
+    rte_eth_link_get_nowait(format_data->port, &link_info);
     format_data->link_speed = link_info.link_speed;
 #if DEBUG
@@ -1531 +1608 @@
         /* Close the device completely, device cannot be restarted */
         if (FORMAT(libtrace)->port != 0xFF)
-            rte_eth_dev_close(FORMAT(libtrace)->port);
-        /* filter here if we used it */
+                rte_eth_dev_callback_unregister(FORMAT(libtrace)->port,
+                                                RTE_ETH_EVENT_INTR_LSC,
+                                                dpdk_lsc_callback,
+                                                FORMAT(libtrace));
+                rte_eth_dev_close(FORMAT(libtrace)->port);
+                /* filter here if we used it */
                 free(libtrace->format_data);
         }