From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH] sky2: skb recycling Date: Tue, 21 Oct 2008 13:38:11 -0700 Message-ID: <20081021133811.68bd5ce1@extreme> References: <20081020190922.7dd6510a@extreme> <20081020.221857.209830018.davem@davemloft.net> <48FE34AF.8050508@hp.com> <48FE386F.8090706@cosmosbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Rick Jones , David Miller , jgarzik@pobox.com, netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail.vyatta.com ([76.74.103.46]:47363 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751907AbYJUUiO convert rfc822-to-8bit (ORCPT ); Tue, 21 Oct 2008 16:38:14 -0400 In-Reply-To: <48FE386F.8090706@cosmosbay.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 21 Oct 2008 22:15:43 +0200 Eric Dumazet wrote: > Rick Jones a =C3=A9crit : > > David Miller wrote: > >> From: Stephen Hemminger > >> Date: Mon, 20 Oct 2008 19:09:22 -0700 > >> > >> > >>> Add support for recycling tx buffers into receive buffers. > >>> This is experimental at this point. > >>> > >>> Signed-off-by: Stephen Hemminger > >> > >> > >> Experimental, but do you have any performance data at all? > >> Just curious... > >=20 > > I've not had a good emily litella moment all day so I'll ask - is t= here=20 > > really that much in the way of suitable skb's which are completely = free=20 > > after transmit completion? >=20 > Or, if we take another way, say a VOIP RTP machine sends and receive = 20.000 > packets per second, each being 200 bytes long, are transmited packet= s > correctly sized at sendto() time to be candidates for recycling ? No. Most locally generate packets aren't going to be right size because they will be too small, cloned or fragmented. It really only helps whe= n forwarding.