Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755470Ab1CAF7y (ORCPT ); Tue, 1 Mar 2011 00:59:54 -0500 Received: from mail-ww0-f44.google.com ([74.125.82.44]:54224 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755146Ab1CAF7x (ORCPT ); Tue, 1 Mar 2011 00:59:53 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=JI6NwMWIc39Gr8dA4pl7e4Lvakil5cTT59EpIgmaf4IS66BSLRb5pcrodpffTi9NJK Gme1bQiYTwG/GLjj8mXZ9UYZaRulI0LLETAvdvixvjidTANesjDoBUGCA1WgMddlLrp1 ZxDsS71F5f3NktfQlJ9SwdR6UtMVq5KW+nzxY= Subject: Re: [PATCH v6] net: add Faraday FTMAC100 10/100 Ethernet driver From: Eric Dumazet To: Po-Yu Chuang Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bhutchings@solarflare.com, joe@perches.com, dilinger@queued.net, mirqus@gmail.com, davem@davemloft.net, Po-Yu Chuang In-Reply-To: References: <1298539762-2242-1-git-send-email-ratbert.chuang@gmail.com> <1298627845-1583-1-git-send-email-ratbert.chuang@gmail.com> <1298634040.2659.32.camel@edumazet-laptop> <1298958336.2676.21.camel@edumazet-laptop> Content-Type: text/plain; charset="UTF-8" Date: Tue, 01 Mar 2011 06:59:48 +0100 Message-ID: <1298959188.2676.32.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1037 Lines: 28 Le mardi 01 mars 2011 à 13:51 +0800, Po-Yu Chuang a écrit : > On Tue, Mar 1, 2011 at 1:45 PM, Eric Dumazet wrote: > > I am only wondering then if not using fragments would be faster then > > (eventually doing copybreaks for small frames like tg3) > > Although not many circumstances are tested. > iperf shows that it is a little faster to use fragments than memcpy, so... This might be a side effect of skb->truesize being smaller with fragments than "regular packets" and socket backlog congestion. If a full page was really accounted for in skb->truesize, instead of used length, performance might be the same or lower :( - skb->truesize += length; + skb->truesize += PAGE_SIZE; This has nothing to do with your driver, but a core implementation detail. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/