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 730E6A04FD; Mon, 23 May 2022 10:50:05 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 63D8A4161A; Mon, 23 May 2022 10:50:05 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 3A04A40041 for ; Mon, 23 May 2022 10:50:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653295802; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yAnMBpIiVsxvq70+giJUGkljGZOAS9oICSlSiGrj2rs=; b=F9ls6/ZVyGGwMFZfgpTA4RVBBimQxdYyGLPkIOyTW4FSNEesvFcmVLU5q04NYTBSNNS6U3 GjW75NTpQcr2pkrOIL+wBHCqJ7sHqF/vFmlszERlqhpxaR7Oje2/F9MsvjErFQnijpwsGA yyYjSdMICjVVT+5bT7U7aYcKAs/vVXA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-328-Iy8PVjjzMd6Agpgn3Oe4Kw-1; Mon, 23 May 2022 04:49:57 -0400 X-MC-Unique: Iy8PVjjzMd6Agpgn3Oe4Kw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C3B95801210; Mon, 23 May 2022 08:49:56 +0000 (UTC) Received: from [10.39.208.27] (unknown [10.39.208.27]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9743C2166B25; Mon, 23 May 2022 08:49:55 +0000 (UTC) Message-ID: <343868e4-45a2-9d7a-0937-6690bc4368c4@redhat.com> Date: Mon, 23 May 2022 10:49:54 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH] vhost: support sync copy when data buffer is small To: "Hu, Jiayu" , "Ma, WenwuX" , "Xia, Chenbo" , "dev@dpdk.org" Cc: "Wang, Yinan" , "He, Xingguang" , "Ling, WeiX" References: <20220411133836.200783-1-wenwux.ma@intel.com> From: Maxime Coquelin In-Reply-To: X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=maxime.coquelin@redhat.com 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 Hi Jiayu, On 5/23/22 02:38, Hu, Jiayu wrote: > Hi Maxime, > >> -----Original Message----- >> From: Maxime Coquelin >> Sent: Tuesday, April 19, 2022 5:10 PM >> To: Ma, WenwuX ; Xia, Chenbo >> ; dev@dpdk.org >> Cc: Hu, Jiayu ; Wang, Yinan ; >> He, Xingguang ; Ling, WeiX >> Subject: Re: [PATCH] vhost: support sync copy when data buffer is small >> >> Hi Wenwu, >> >> On 4/11/22 15:38, Wenwu Ma wrote: >>> In async datapath, if the length of data buffer is less than 256, the >>> data will be copied by CPU instead of DMA. >>> >>> Signed-off-by: Wenwu Ma >>> --- >>> lib/vhost/vhost.h | 6 ++- >>> lib/vhost/virtio_net.c | 96 ++++++++++++++++++++++++++++++------------ >>> 2 files changed, 73 insertions(+), 29 deletions(-) >>> >> >> As I mentioned in the past, let's have a DMA-only solution working before >> trying to support CPU copy for small packets. > > Thanks for your suggestion. > > For "DMA-only solution working", do you mean community reaches an > agreement on OVS DSA design? The reason of asking this question is > that we will have some following patches around async vhost in 22.11, > like vhostpmd supporting async vhost data-path. Regarding your suggestion, > do you think they also need to be deferred until "DMA-only solution working"? No, I was just referring to CPU copy for small buffers features. Thanks, Maxime > Thanks, > Jiayu > >> >> Thanks, >> Maxime >