From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from colo.lackof.org (colo.lackof.org [198.49.126.79]) by dsl2.external.hp.com (Postfix) with ESMTP id 3D3D2483E for ; Mon, 10 Nov 2003 10:35:27 -0700 (MST) Date: Mon, 10 Nov 2003 10:35:25 -0700 From: Grant Grundler To: Joel Soete Cc: parisc-linux Subject: Re: [parisc-linux] C110 builtin nic slow? Message-ID: <20031110173525.GC24664@colo.lackof.org> References: <3F969FFE00009EA4@ocpmta2.freegates.net> <3F969FFE00009F73@ocpmta2.freegates.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <3F969FFE00009F73@ocpmta2.freegates.net> Sender: parisc-linux-admin@lists.parisc-linux.org Errors-To: parisc-linux-admin@lists.parisc-linux.org List-Help: List-Post: List-Subscribe: , List-Id: parisc-linux developers list List-Unsubscribe: , List-Archive: On Mon, Nov 10, 2003 at 03:00:37PM +0100, Joel Soete wrote: > if (pkt_len > rx_copybreak) { > struct sk_buff *newskb; yup - the rx_copybreak support is exactly what I'm talking about. tulip driver has similar support. > /* Copy frames shorter than rx_copybreak, otherwise pass on up in > * a full sized sk_buff. Value of 100 stolen from tulip.c (!alpha). > */ > static int rx_copybreak = 100; The comment is wrong. Tulip uses 1518 for nearly everything but x86. ie it copies all packets since the MTU is <= 1518. > This last notice seems what I am loocking for? > Have you a better idea then try and test (ie rx_copybreak=512, test, rx_copybreak=256, > ... and btw rx_copybreak = PKT_BUF_SZ == 1536)? > Or is it better to tiddle code before? I don't know. It depends on if/when the misaligned access happens. It's possible the misaligned access is less expensive than the full copy on your machine. grant