From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 1E620A0A02; Thu, 20 Oct 2022 09:47:54 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 0152442C5C; Thu, 20 Oct 2022 09:47:54 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mails.dpdk.org (Postfix) with ESMTP id A9C7542C4D for ; Thu, 20 Oct 2022 09:47:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666252072; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=y/yOBrFGzzUPUane7e6a50e66WQC1HhJ9S6r9/+owYg=; b=Pii/ULhlSbZPaRMu3dG1Wol8mr88sQHau1UoFj6fi/HrLwU4FEH4x4CjgGemxR1NReD4+w KwnnwwX3zETPU7hMtBPQpX4W3pjjaOZW5hGJbkhhZoBSkm0NZzkK1D7tCXtzTunhOBR8AJ Pd64PKAOYEF7+Rjn9U+iufGLx//zdVc= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-659-PyMv5Iw_PQivqCgFPVl0VQ-1; Thu, 20 Oct 2022 03:47:50 -0400 X-MC-Unique: PyMv5Iw_PQivqCgFPVl0VQ-1 Received: by mail-wm1-f72.google.com with SMTP id c5-20020a1c3505000000b003c56da8e894so1304963wma.0 for ; Thu, 20 Oct 2022 00:47:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:subject:from:references:to :content-language:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=y/yOBrFGzzUPUane7e6a50e66WQC1HhJ9S6r9/+owYg=; b=tr3KZ7MlUcUzs/ufb/FcARharoZLtQcZPJ1eNsOz3DiQwNJs75pD7QdRqXDf8Xh28I wIdtfaRJbYvZGsaAmI2ccEcX/PVVxxgxLNiiW8V1EYOeFyX0cY9SeQuhyHrdqtz8YTS1 cuVFe1ujS8CxaxEVWJ5EB354EbLpXjey+mteQoc0UnMUmXSUUDSsX9o+1TQLlQ7BzeO1 M6Pz+7zG8SGdByLPF3OldPdySvHE22uMt31JUgZcnurBSNQfG8V+1EIgHwhbLTy70VwS Tv2pzyl+k7UdK66A6KPI+AGPCFd0ndMg+WoZ0fLy0rtrmO1dyzxkGC+T0V9wgT27tw/Y tNyg== X-Gm-Message-State: ACrzQf3NlzGbpQESfgOplL+HzokU6jpjpJBZ2oBn7Khx08UWM2gJt2dV PzacNlkNUzWNSAQyuIzzvtnx4XuyW75KdWCpSQbu7GPNdYg+vGudUOD832JHvxuB42JHZX2RRCO PMzA= X-Received: by 2002:adf:f2cd:0:b0:22e:49c0:aa3b with SMTP id d13-20020adff2cd000000b0022e49c0aa3bmr7712304wrp.97.1666252069580; Thu, 20 Oct 2022 00:47:49 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5XsMi6bKAm3WXh9epi+bmFQlIvgv/qjBRadWufXyCRKmIH7+Q3KbVr+nrNK5OT+6oXsFS7dA== X-Received: by 2002:adf:f2cd:0:b0:22e:49c0:aa3b with SMTP id d13-20020adff2cd000000b0022e49c0aa3bmr7712294wrp.97.1666252069352; Thu, 20 Oct 2022 00:47:49 -0700 (PDT) Received: from [192.168.0.36] ([78.19.110.164]) by smtp.gmail.com with ESMTPSA id iw6-20020a05600c54c600b003b4e009deb2sm2300345wmb.41.2022.10.20.00.47.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 20 Oct 2022 00:47:48 -0700 (PDT) Message-ID: <30c5f90a-acd5-eacb-7ad9-8e8e6819d67d@redhat.com> Date: Thu, 20 Oct 2022 08:47:47 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 To: "Zhou, YidingX" , "dev@dpdk.org" References: <20221018102602.217673-1-yidingx.zhou@intel.com> <20221019075432.9698-1-yidingx.zhou@intel.com> From: Kevin Traynor Subject: Re: [PATCH v2] net/iavf: revert fix VLAN insertion In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On 20/10/2022 02:33, Zhou, YidingX wrote: > > >> -----Original Message----- >> From: Kevin Traynor >> Sent: Wednesday, October 19, 2022 4:53 PM >> To: Zhou, YidingX ; dev@dpdk.org >> Subject: Re: [PATCH v2] net/iavf: revert fix VLAN insertion >> >> On 19/10/2022 08:54, Yiding Zhou wrote: >>> When the kernel driver tells to use the L2TAG2 field for VLAN >>> insertion, the context descriptor needs to be used. There is an issue >>> on the vector Tx path, because it does not support the context descriptor. >>> >>> The previous commit forces to select normal path to avoid the above >>> issue, but it results in a performance loss of around 40%. So it needs >>> to be reverted and the original issue needed to be fixed by rework. >>> >> >> Thank you, that is a much clearer explanation. >> >> Now on the approach, the commit being reverted says: >> "When the driver tells the VF to insert VLAN tag using the L2TAG2 field, vector >> Tx path does not use Tx context descriptor and would cause VLAN tag inserted >> into the wrong location." >> >> So it means this revert is solving a performance regression, but re-introducing >> the functional issue above. >> >> Is there a correct fix for the original issue sent that can be applied too? If not, >> wouldn't it be better to wait until it is before doing the revert? >> > > Sorry, there is no correct fix yet. > We plan to support context descriptor on vector path to fix the original issue, > It may take more time and cannot be completed within this cycle. > ok, but you didn't answer the second question. "When the driver tells the VF to insert VLAN tag using the L2TAG2 field, vector Tx path does not use Tx context descriptor and would cause VLAN tag inserted into the wrong location." Please explain your justification for (re-)introducing this bug? Why is better to get (corrupt?) packets with incorrect VLAN tags than lose performance for this case? Or have I mis-interpreted the patches. >>> To reverts >>> commit 0d58caa7d6d1 ("net/iavf: fix VLAN insertion") >>> >>> Fixes: 0d58caa7d6d1 ("net/iavf: fix VLAN insertion") >>> >>> Signed-off-by: Yiding Zhou >>> --- >>> drivers/net/iavf/iavf_rxtx_vec_common.h | 3 --- >>> 1 file changed, 3 deletions(-) >>> >>> diff --git a/drivers/net/iavf/iavf_rxtx_vec_common.h >>> b/drivers/net/iavf/iavf_rxtx_vec_common.h >>> index 4ab22c6b2b..a59cb2ceee 100644 >>> --- a/drivers/net/iavf/iavf_rxtx_vec_common.h >>> +++ b/drivers/net/iavf/iavf_rxtx_vec_common.h >>> @@ -253,9 +253,6 @@ iavf_tx_vec_queue_default(struct iavf_tx_queue *txq) >>> if (txq->offloads & IAVF_TX_NO_VECTOR_FLAGS) >>> return -1; >>> >>> - if (txq->vlan_flag == IAVF_TX_FLAGS_VLAN_TAG_LOC_L2TAG2) >>> - return -1; >>> - >>> if (txq->offloads & IAVF_TX_VECTOR_OFFLOAD) >>> return IAVF_VECTOR_OFFLOAD_PATH; >>> >