Changeset 95364aa

Timestamp:

09/04/14 16:58:11 (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:

3f58e38

Parents:

66baa54

Message:

Change thresholds to work with e1000 series cards

• Fix some typos

File:

• lib/format_dpdk.c (modified) (9 diffs)

lib/format_dpdk.c

@@ -372 +372 @@
 #endif
 
-static inline int dpdk_init_enviroment(char * uridata, struct dpdk_format_data_t * format_data,
+static inline int dpdk_init_environment(char * uridata, struct dpdk_format_data_t * format_data,
                                         char * err, int errlen) {
     int ret; /* Returned error codes */
@@ -395 +395 @@
     int argc = sizeof(argv) / sizeof(argv[0]) - 1;
     
-    /* This initilises the Enviroment Abstraction Layer (EAL)
+    /* This initialises the Environment Abstraction Layer (EAL)
+    /* This initialises the Environment Abstraction Layer (EAL)
      * If we had slave workers these are put into WAITING state
      * 
      * Basically binds this thread to a fixed core, which we choose as
      * the last core on the machine (assuming fewer interrupts mapped here).
-     * "-c" controls the cpu mask 0x1=1st core 0x2=2nd 0x4=3rd and so om
+     * "-c" controls the cpu mask 0x1=1st core 0x2=2nd 0x4=3rd and so on
      * "-n" the number of memory channels into the CPU (hardware specific)
      *      - Most likely to be half the number of ram slots in your machine.
@@ -508 +509 @@
 #endif
 
-    if (dpdk_init_enviroment(libtrace->uridata, FORMAT(libtrace), err, sizeof(err)) != 0) {
+    if (dpdk_init_environment(libtrace->uridata, FORMAT(libtrace), err, sizeof(err)) != 0) {
         trace_set_err(libtrace, TRACE_ERR_INIT_FAILED, "%s", err);
         free(libtrace->format_data);
@@ -541 +542 @@
 #endif
 
-    if (dpdk_init_enviroment(libtrace->uridata, FORMAT(libtrace), err, sizeof(err)) != 0) {
+    if (dpdk_init_environment(libtrace->uridata, FORMAT(libtrace), err, sizeof(err)) != 0) {
         trace_set_err_out(libtrace, TRACE_ERR_INIT_FAILED, "%s", err);
         free(libtrace->format_data);
@@ -637 +638 @@
 static const struct rte_eth_txconf tx_conf = {
         .tx_thresh = {
-                .pthresh = 36,/* TX_PTHRESH prefetch */
-                .hthresh = 0,/* TX_HTHRESH host */
-                .wthresh = 4,/* TX_WTHRESH writeback */
+        /**
+         * TX_PTHRESH prefetch
+         * Set on the NIC, if the number of unprocessed descriptors to queued on
+         * the card fall below this try grab at least hthresh more unprocessed
+         * descriptors.
+         */
+                .pthresh = 36,
+
+        /* TX_HTHRESH host
+         * Set on the NIC, the batch size to prefetch unprocessed tx descriptors.
+         */
+                .hthresh = 0,
+        
+        /* TX_WTHRESH writeback
+         * Set on the NIC, the number of sent descriptors before writing back
+         * status to confirm the transmission. This is done more efficiently as
+         * a bulk DMA-transfer rather than writing one at a time.
+         * Similar to tx_free_thresh however this is applied to the NIC, where
+         * as tx_free_thresh is when DPDK will check these. This is extended
+         * upon by tx_rs_thresh (10Gbit cards) which doesn't write all
+         * descriptors rather only every n'th item, reducing DMA memory bandwidth.
+         */
+                .wthresh = 4,
         },
-        .tx_free_thresh = 0, /* Use PMD default values */
-        .tx_rs_thresh = 0, /* Use PMD default values */
+
+    /* Used internally by DPDK rather than passed to the NIC. The number of
+     * packet descriptors to send before checking for any responses written
+     * back (to confirm the transmission). Default = 32 if set to 0)
+     */
+        .tx_free_thresh = 0,
+
+    /* This is the Report Status threshold, used by 10Gbit cards,
+     * This signals the card to only write back status (such as 
+     * transmission successful) after this minimum number of transmit
+     * descriptors are seen. The default is 32 (if set to 0) however if set
+     * to greater than 1 TX wthresh must be set to zero, because this is kindof
+     * a replacement. See the dpdk programmers guide for more restrictions.
+     */
+        .tx_rs_thresh = 1,
 };
 
@@ -656 +690 @@
 
     /* First time started we need to alloc our memory, doing this here 
-     * rather than in enviroment setup because we don't have snaplen then */
+     * rather than in environment setup because we don't have snaplen then */
     if (format_data->paused == DPDK_NEVER_STARTED) {
         if (format_data->snaplen == 0) {
@@ -722 +756 @@
         return -1;
     }
-    /* Initilise the TX queue a minimum value if using this port for
+    /* Initialise the TX queue a minimum value if using this port for
      * receiving. Otherwise a larger size if writing packets.
      */
@@ -733 +767 @@
         return -1;
     }
-    /* Initilise the RX queue with some packets from memory */
+    /* Initialise the RX queue with some packets from memory */
     ret = rte_eth_rx_queue_setup(format_data->port, format_data->queue_id,
                             format_data->nb_rx_buf, SOCKET_ID_ANY, 
@@ -768 +802 @@
 #endif
 
-    /* We have now successfully started/unpased */
+    /* We have now successfully started/unpaused */
     format_data->paused = DPDK_RUNNING;