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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 919C2C04AB6 for ; Fri, 31 May 2019 18:00:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74A2E26D9A for ; Fri, 31 May 2019 18:00:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726718AbfEaSAv (ORCPT ); Fri, 31 May 2019 14:00:51 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:47390 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726359AbfEaSAv (ORCPT ); Fri, 31 May 2019 14:00:51 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id B3BCC14BEAFA9; Fri, 31 May 2019 11:00:50 -0700 (PDT) Date: Fri, 31 May 2019 11:00:50 -0700 (PDT) Message-Id: <20190531.110050.517935401011629843.davem@davemloft.net> To: brouer@redhat.com Cc: barbette@kth.se, xdp-newbies@vger.kernel.org, toke@redhat.com, saeedm@mellanox.com, leonro@mellanox.com, tariqt@mellanox.com, netdev@vger.kernel.org Subject: Re: Bad XDP performance with mlx5 From: David Miller In-Reply-To: <20190531181817.34039c9f@carbon> References: <2218141a-7026-1cb8-c594-37e38eef7b15@kth.se> <20190531181817.34039c9f@carbon> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 31 May 2019 11:00:51 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jesper Dangaard Brouer Date: Fri, 31 May 2019 18:18:17 +0200 > On Fri, 31 May 2019 08:51:43 +0200 Tom Barbette wrote: > >> I wonder if it doesn't simply come from mlx5/en_main.c: >> rq->buff.map_dir = rq->xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE; >> > > Nope, that is not the problem. And it's easy to test this theory by forcing DMA_FROM_DEVICE.