From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FE24C43334 for ; Sat, 23 Jul 2022 10:35:17 +0000 (UTC) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 26C734067C; Sat, 23 Jul 2022 12:35:16 +0200 (CEST) Received: from smartserver.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by mails.dpdk.org (Postfix) with ESMTP id 2A7514021E; Sat, 23 Jul 2022 12:35:15 +0200 (CEST) X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Subject: Test non-scattered jumbo frames Date: Sat, 23 Jul 2022 12:35:14 +0200 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D871E1@smartserver.smartshare.dk> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: Test non-scattered jumbo frames Thread-Index: Adief+TjBFiCTso6QIqcxYcp+7Q+3g== From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: Cc: 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 DPDK DTS team, Some Linux Ethernet drivers have the braindead idea that when configured = for max packet length slightly above 1518, e.g. 1536, they will scatter = packets into segments of 1024 byte, so even normal size packets get = scattered. I would like ensure that DPDK PMDs don't do something = remotely similar. I have looked at the test plans for Scattered Packets (chapter 135) and = Jumbo Frames (chapter 81). Some applications do not use scattered packets, but still might support = jumbo frames, so I would like to suggest two test cases to verify that = PMDs don't generate scattered packets on RX, even for jumbo frames: 1. Using --mbuf-size=3D2048 --max-pkt-len=3D1600, received packets up to = 1600 byte should not be scattered on RX. 2. Using --mbuf-size=3D16384 --max-pkt-len=3D9600, received packets up = to 9600 byte should not be scattered on RX. Med venlig hilsen / Kind regards, -Morten Br=F8rup