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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AEF9C433F5 for ; Thu, 29 Sep 2022 15:41:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235720AbiI2Plo (ORCPT ); Thu, 29 Sep 2022 11:41:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236013AbiI2Pkq (ORCPT ); Thu, 29 Sep 2022 11:40:46 -0400 Received: from vps0.lunn.ch (vps0.lunn.ch [185.16.172.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B31CE38442; Thu, 29 Sep 2022 08:40:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=gihPt2bKu+pozhoRu7JQZyvc66MP3qC1ZK9A68zwRwM=; b=1wW7lP2TaDcg9AXO2Kk7JN4pM6 jlDCOUAAun4zRV8fj8m0ZNgD8QauQO8aR/FcAX9UATuNp31jlKfcsweulrmO+AFYbGT6dKvwxPumA GVqkn8lIruIaHI7Z1iK+np15l27nHFGf/kZ4mALioayC3Ro4mQlWtwFb++KVM6p3YHhE=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1odvdk-000d5U-OT; Thu, 29 Sep 2022 17:39:56 +0200 Date: Thu, 29 Sep 2022 17:39:56 +0200 From: Andrew Lunn To: Jesper Dangaard Brouer Cc: Shenwei Wang , brouer@redhat.com, Joakim Zhang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "imx@lists.linux.dev" Subject: Re: [EXT] Re: [PATCH 1/1] net: fec: add initial XDP support Message-ID: References: <20220928152509.141490-1-shenwei.wang@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 29, 2022 at 05:28:43PM +0200, Jesper Dangaard Brouer wrote: > > > On 29/09/2022 15.26, Shenwei Wang wrote: > > > > > From: Andrew Lunn > > > Sent: Thursday, September 29, 2022 8:23 AM > [...] > > > > > > > I actually did some compare testing regarding the page pool for normal > > > > traffic. So far I don't see significant improvement in the current > > > > implementation. The performance for large packets improves a little, > > > > and the performance for small packets get a little worse. > > > > > > What hardware was this for? imx51? imx6? imx7 Vybrid? These all use the FEC. > > > > I tested on imx8qxp platform. It is ARM64. > > On mvneta driver/platform we saw huge speedup replacing: > > page_pool_release_page(rxq->page_pool, page); > with > skb_mark_for_recycle(skb); > > As I mentioned: Today page_pool have SKB recycle support (you might have > looked at drivers that didn't utilize this yet), thus you don't need to > release the page (page_pool_release_page) here. Instead you could simply > mark the SKB for recycling, unless driver does some page refcnt tricks I > didn't notice. > > On the mvneta driver/platform the DMA unmap (in page_pool_release_page) was > very expensive. This imx8qxp platform might have faster DMA unmap in case is > it cache-coherent. I don't know about imx8qxp, but i've played with imx6 and Vybrid, and cache flush and invalidate are very expensive. Andrew