From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id D4FD8A0471 for ; Tue, 16 Jul 2019 16:28:32 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 9E9EA2BF5; Tue, 16 Jul 2019 16:28:32 +0200 (CEST) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id C420023D; Tue, 16 Jul 2019 16:28:30 +0200 (CEST) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jul 2019 07:28:28 -0700 X-IronPort-AV: E=Sophos;i="5.63,498,1557212400"; d="scan'208";a="178566665" Received: from bricha3-mobl.ger.corp.intel.com ([10.237.221.51]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jul 2019 07:28:26 -0700 Date: Tue, 16 Jul 2019 15:28:23 +0100 From: Bruce Richardson To: Ferruh Yigit Cc: Andrew Rybchenko , "A.McLoughlin" , Wenzhuo Lu , Jingjing Wu , Bernard Iremonger , dev@dpdk.org, david.marchand@redhat.com, stable@dpdk.org, Thomas Monjalon , Stephen Hemminger Message-ID: <20190716142823.GA1313@bricha3-MOBL.ger.corp.intel.com> References: <20190712083221.4987-1-aideen.mcloughlin@intel.com> <6dec383f-a559-7036-8ecd-22f11f2c1d5f@solarflare.com> <131f21d3-dd47-4536-655a-0bb7af54ee0e@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <131f21d3-dd47-4536-655a-0bb7af54ee0e@intel.com> User-Agent: Mutt/1.11.4 (2019-03-13) Subject: Re: [dpdk-dev] [PATCH] app/testpmd: fix doubling of 'total TX dropped' X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Jul 16, 2019 at 03:23:03PM +0100, Ferruh Yigit wrote: > On 7/16/2019 1:23 PM, Andrew Rybchenko wrote: > > On 7/15/19 5:53 PM, Ferruh Yigit wrote: > >> On 7/12/2019 9:32 AM, A.McLoughlin wrote: > >>> The 'Accumulated forward statistics for all ports' incorrectly displayed > >>> double the actual value for 'total_tx_dropped'. This was because 2 > >>> lines in the same function both incremented total_tx_dropped every time > >>> a packet was dropped. I removed one of these lines to fix this issue. > >>> > >>> Fixes: 53324971a14e ("app/testpmd: display/clear forwarding stats on demand") > >>> Cc: david.marchand@redhat.com > >>> Cc: stable@dpdk.org > >>> > >>> Signed-off-by: A.McLoughlin > >>> --- > >>> app/test-pmd/testpmd.c | 1 - > >>> 1 file changed, 1 deletion(-) > >>> > >>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c > >>> index 3ed3523b7..c41bada50 100644 > >>> --- a/app/test-pmd/testpmd.c > >>> +++ b/app/test-pmd/testpmd.c > >>> @@ -1555,7 +1555,6 @@ fwd_stats_display(void) > >>> total_recv += stats.ipackets; > >>> total_xmit += stats.opackets; > >>> total_rx_dropped += stats.imissed; > >>> - total_tx_dropped += ports_stats[pt_id].tx_dropped; > >>> total_tx_dropped += stats.oerrors; > >>> total_rx_nombuf += stats.rx_nombuf; > >>> > >>> > >> > >> Hi Aideen, > >> > >> Indeed 'rte_eth_stats->oerrors' and 'tx_dropped' are different values, > >> > >> in testpmd, 'TX-total' is taken as "total_xmit + total_tx_dropped", from this > >> description it may be fair to say > >> "total_tx_dropped = oerrors + tx_dropped" > >> > >> This is easier to see in HW devices, 'oerrors' is the packets sent to HW but HW > >> reported failure for some reason, so these packets not transmitted to the medium. > >> 'tx_dropped' is mostly calculated by application, driver returns packets that > >> can't able to sent to HW, so application can re-try to send or free them and > >> increase 'tx_dropped' counter. > >> > >> > >> The problem is in the virtual drivers, the packets not able to sent are > >> calculated as 'oerrors' and tx_burst functions returns the number of the > >> successfully sent packets which cause application calculate remaining ones as > >> 'tx_dropped' which cause the duplication. > > > > I don't understand how it is. Tx burst returns a number of owned packets > > (either successfully transmitted or internally dropped/freed). If it is > > smaller than number of packets in request, other packets are either > > retried or calculated as tx_dropped. > > Virtual PMDs, at least the ones I checked, calculating not sent packets as > error, also application calculates them as tx_dropped. > > Like: > https://git.dpdk.org/dpdk/tree/drivers/net/ring/rte_eth_ring.c?h=v19.08-rc1#n97 > That is probably incorrect to do. Virtual PMDs should behave as real ones do as far as possible. I think we should change them to not count as errors any that are not handled by the driver, provided those are returned to the app. /Bruce