Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261355AbVAGRYS (ORCPT ); Fri, 7 Jan 2005 12:24:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261356AbVAGRYR (ORCPT ); Fri, 7 Jan 2005 12:24:17 -0500 Received: from fw.osdl.org ([65.172.181.6]:40877 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261355AbVAGRYP (ORCPT ); Fri, 7 Jan 2005 12:24:15 -0500 Date: Fri, 7 Jan 2005 09:23:39 -0800 (PST) From: Linus Torvalds To: Alan Cox cc: 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: <1105110401.17166.346.camel@localhost.localdomain> Message-ID: References: <41DE9D10.B33ED5E4@tv-sign.ru> <1105110401.17166.346.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 839 Lines: 22 On Fri, 7 Jan 2005, Alan Cox wrote: > > That would break stuff, but holding the last page until it fills 4K > would work, or just basic sg coalescing when possible. The pipe > behaviour - particularly size and size of atomic writes is defined by > SuS and there are people who use pipes two ways between apps and use the > guarantees to avoid deadlocks Hmm.. Are there really any other guarantees than the atomicity guarantee for a PIPE_BUF transfer? I don't see any in SuS.. That said, existing practice obviously always trumps paper standards, and yes, coalescing is possible. Linus - 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/