From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756704Ab2D3UDz (ORCPT ); Mon, 30 Apr 2012 16:03:55 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60347 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756454Ab2D3UDx (ORCPT ); Mon, 30 Apr 2012 16:03:53 -0400 Message-ID: <4F9EEFF5.4000703@zytor.com> Date: Mon, 30 Apr 2012 13:03:01 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-Version: 1.0 To: Linus Torvalds CC: Linux Kernel Mailing List , Michael Tokarev , Alan Cox , Ian Kent , Thomas Meyer , autofs@vger.kernel.org Subject: Re: autofs: make the autofsv5 packet file descriptor use a packetized pipe References: <20120429205429.63CCD7C0064@ra.kernel.org> <4F9DD994.70202@zytor.com> <4F9DDD3E.6010801@zytor.com> In-Reply-To: <4F9DDD3E.6010801@zytor.com> X-Enigmail-Version: 1.4.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/29/2012 05:30 PM, H. Peter Anvin wrote: > Incidentally, I think there is a good reason to add a v6 packet type > regardless, for efficiency: with packetized pipes there really is no > point in sending a packet which is mostly padding for no good reason. Thinking about it some more: for v6, I wouldn't use a packetized pipe at all (due to the unnecessary extra buffer consumption.) Instead just put the message size in the header and read a large chunk, which may end up being more than one packet and may end up with a partial packet at the end. *This is okay*, because there is only one reader, and any additional data needed will be gotten the next time around the loop. -hpa