app/testpmd: fix statistics after reset

Currently, when running start/clear stats&xstats/stop command many times
based on testpmd application, there are incorrect forward Rx/Tx-packets
stats as below:
---------------------- Forward statistics for port 0  --------------
RX-packets: 18446744073709544808 RX-dropped: 0                <snip>
TX-packets: 18446744073709536616 TX-dropped: 0                <snip>
--------------------------------------------------------------------

The root cause as below:
1. The struct rte_port of testpmd.h has a member variable "struct
   rte_eth_stats stats" to store the last port statistics.
2. When running start command, it execute cmd_start_parsed ->
   start_packet_forwarding -> fwd_stats_reset, which call
   rte_eth_stats_get API function to save current port statistics.
3. When running stop command, it execute fwd_stats_display, which call
   rte_eth_stats_get to get current port statistics, and then minus last
   port statistics.
4. If we run clear stats or xstats after start command, then run stop,
   it may display above incorrect stats because the current
   Rx/Tx-packets is lower than the last saved RX/TX-packets(uint64_t
   overflow).

This patch fixes it by clearing last port statistics when executing
"clear stats/xstats" command.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 035d336..5381207 100644 (file)
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -234,11 +234,26 @@ nic_stats_display(portid_t port_id)
 void
 nic_stats_clear(portid_t port_id)
 {
+       int ret;
+
        if (port_id_is_invalid(port_id, ENABLED_WARN)) {
                print_valid_ports();
                return;
        }
-       rte_eth_stats_reset(port_id);
+
+       ret = rte_eth_stats_reset(port_id);
+       if (ret != 0) {
+               printf("%s: Error: failed to reset stats (port %u): %s",
+                      __func__, port_id, strerror(ret));
+               return;
+       }
+
+       ret = rte_eth_stats_get(port_id, &ports[port_id].stats);
+       if (ret != 0) {
+               printf("%s: Error: failed to get stats (port %u): %s",
+                      __func__, port_id, strerror(ret));
+               return;
+       }
        printf("\n  NIC statistics for port %d cleared\n", port_id);
 }
 
@@ -314,10 +329,19 @@ nic_xstats_clear(portid_t port_id)
                print_valid_ports();
                return;
        }
+
        ret = rte_eth_xstats_reset(port_id);
        if (ret != 0) {
                printf("%s: Error: failed to reset xstats (port %u): %s",
                       __func__, port_id, strerror(ret));
+               return;
+       }
+
+       ret = rte_eth_stats_get(port_id, &ports[port_id].stats);
+       if (ret != 0) {
+               printf("%s: Error: failed to get stats (port %u): %s",
+                      __func__, port_id, strerror(ret));
+               return;
        }
 }
 

diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
index 19260cc..581cd45 100644 (file)
--- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
+++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
@@ -237,7 +237,7 @@ Display the RSS hash functions and RSS hash key of a port::
 clear port
 ~~~~~~~~~~
 
-Clear the port statistics for a given port or for all ports::
+Clear the port statistics and forward engine statistics for a given port or for all ports::
 
    testpmd> clear port (info|stats|xstats|fdir|stat_qmap) (port_id|all)