From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: net: more accurate skb truesize - regression on Microblaze Date: Tue, 10 Apr 2012 13:32:09 +0200 Message-ID: <1334057529.3126.90.camel@edumazet-glaptop> References: <4F83EB0E.4020104@monstr.eu> <1334046444.3126.12.camel@edumazet-glaptop> <1334046746.3126.13.camel@edumazet-glaptop> <4F83F166.4010208@monstr.eu> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, John Williams , David Miller To: monstr@monstr.eu Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:62278 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751366Ab2DJLcP (ORCPT ); Tue, 10 Apr 2012 07:32:15 -0400 Received: by bkcik5 with SMTP id ik5so4109865bkc.19 for ; Tue, 10 Apr 2012 04:32:14 -0700 (PDT) In-Reply-To: <4F83F166.4010208@monstr.eu> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2012-04-10 at 10:37 +0200, Michal Simek wrote: > On 04/10/2012 10:32 AM, Eric Dumazet wrote: > > On Tue, 2012-04-10 at 10:27 +0200, Eric Dumazet wrote: > > > >> BTW, some NIC drivers are known to provide fat skb in their rx path, and > >> need to be fixed as well. (Some others just lie about skb->truesize to > >> avoid the tcp slowdown, see my previous iwlwifi patch) > >> > >> > > > > What is the driver you currently use on your platform ? > > Using Xilinx ll_temac(in mainline) and axi_emac. > ll_temac allocates XTE_MAX_JUMBO_FRAME_SIZE frames, even for MTU=1500 ? Trying to allocate smaller packets would definitely help your tcp receiver performance and overall reliability (order-0 allocations instead of order-2)