Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261941AbVANKip (ORCPT ); Fri, 14 Jan 2005 05:38:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261943AbVANKip (ORCPT ); Fri, 14 Jan 2005 05:38:45 -0500 Received: from mail15.syd.optusnet.com.au ([211.29.132.196]:51392 "EHLO mail15.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S261941AbVANKil (ORCPT ); Fri, 14 Jan 2005 05:38:41 -0500 From: Peter Chubb MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16871.39882.69994.86833@wombat.chubb.wattle.id.au> Date: Fri, 14 Jan 2005 21:15:38 +1100 To: Chris Friesen Cc: Mike Waychison , Linus Torvalds , Alan Cox , Oleg Nesterov , William Lee Irwin III , Linux Kernel Mailing List Subject: Re: Make pipe data structure be a circular list of pages, rather than In-Reply-To: <41DF1F3D.3030006@nortelnetworks.com> References: <41DE9D10.B33ED5E4@tv-sign.ru> <1105113998.24187.361.camel@localhost.localdomain> <41DEF81B.60905@sun.com> <41DF1F3D.3030006@nortelnetworks.com> X-Mailer: VM 7.17 under 21.4 (patch 15) "Security Through Obscurity" XEmacs Lucid Comments: Hyperbole mail buttons accepted, v04.18. X-Face: GgFg(Z>fx((4\32hvXq<)|jndSniCH~~$D)Ka:P@e@JR1P%Vr}EwUdfwf-4j\rUs#JR{'h# !]])6%Jh~b$VA|ALhnpPiHu[-x~@<"@Iv&|%R)Fq[[,(&Z'O)Q)xCqe1\M[F8#9l8~}#u$S$Rm`S9% \'T@`:&8>Sb*c5d'=eDYI&GF`+t[LfDH="MP5rwOO]w>ALi7'=QJHz&y&C&TE_3j! Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1072 Lines: 26 >>>>> "Chris" == Chris Friesen writes: Chris> Mike Waychison wrote: >> This got me to thinking about how you can heuristically optimize >> away coalescing support and still allow PAGE_SIZE bytes minimum in >> the effective buffer. Chris> While coalescing may be a win in some cases, there should also Chris> be some way to tell the kernel to NOT coalesce, to handle the Chris> case where you want minimum latency at the cost of some Chris> throughput. SysVr4 pipes used to have two modes: a `legacy' mode that coalesced data, and a `message' mode that preserved message boundaries. Seems to me that we could be about to have the latter in Linux... -- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au The technical we do immediately, the political takes *forever* - 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/