From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261361AbVFETxu (ORCPT ); Sun, 5 Jun 2005 15:53:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261507AbVFETxu (ORCPT ); Sun, 5 Jun 2005 15:53:50 -0400 Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:57527 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S261361AbVFETxs (ORCPT ); Sun, 5 Jun 2005 15:53:48 -0400 Date: Sun, 05 Jun 2005 12:52:49 -0700 (PDT) Message-Id: <20050605.125249.104050648.davem@davemloft.net> To: nickpiggin@yahoo.com.au Cc: herbert@gondor.apana.org.au, mbligh@mbligh.org, jschopp@austin.ibm.com, mel@csn.ul.ie, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: Avoiding external fragmentation with a placement policy Version 12 From: "David S. Miller" In-Reply-To: <42A10ED2.7020205@yahoo.com.au> References: <42A10ED2.7020205@yahoo.com.au> X-Mailer: Mew version 3.3 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Nick Piggin Date: Sat, 04 Jun 2005 12:15:46 +1000 > Herbert Xu wrote: > > With Dave's latest super-TSO patch, TCP over loopback will only be > > doing order-0 allocations in the common case. UDP and others may > > still do large allocations but that logic is all localised in > > ip_append_data. > > > > So if we wanted we could easily remove most large allocations over > > the loopback device. > > I would be very interested to look into that. I would be > willing to do benchmarks on a range of machines too if > that would be of any use to you. Even without the super-TSO patch, we never do larger than PAGE_SIZE allocations for sendmsg() when the device is scatter-gather capable (as indicated in netdev->flags). Loopback does set this bit. This PAGE_SIZE limit comes from net/ipv4/tcp.c:select_size().