From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: What to expect after 0.99.8 Date: Tue, 04 Oct 2005 19:48:51 -0700 Message-ID: <43433F13.1080306@zytor.com> References: <7v7jcvxxrl.fsf@assigned-by-dhcp.cox.net> <7vmzlqnwmw.fsf@assigned-by-dhcp.cox.net> <7v1x32l0gz.fsf@assigned-by-dhcp.cox.net> <20051004071210.GA18716@localdomain> <434296F1.5030006@zytor.com> <20051004154640.GC4682@kiste.smurf.noris.de> <4342AF4B.7020806@zytor.com> <7vu0fx9c1c.fsf@assigned-by-dhcp.cox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Oct 05 04:49:52 2005 Return-path: Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1EMzLr-00065M-2C for gcvg-git@gmane.org; Wed, 05 Oct 2005 04:49:51 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751209AbVJECtI (ORCPT ); Tue, 4 Oct 2005 22:49:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751210AbVJECtI (ORCPT ); Tue, 4 Oct 2005 22:49:08 -0400 Received: from terminus.zytor.com ([192.83.249.54]:9697 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S1751209AbVJECtG (ORCPT ); Tue, 4 Oct 2005 22:49:06 -0400 Received: from [10.4.1.13] (yardgnome.orionmulti.com [209.128.68.65]) (authenticated bits=0) by terminus.zytor.com (8.13.4/8.13.4) with ESMTP id j952mt77020039 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 4 Oct 2005 19:48:56 -0700 User-Agent: Mozilla Thunderbird 1.0.7-1.1.fc4 (X11/20050929) X-Accept-Language: en-us, en To: Junio C Hamano In-Reply-To: <7vu0fx9c1c.fsf@assigned-by-dhcp.cox.net> X-Virus-Scanned: ClamAV version 0.87, clamav-milter version 0.87 on localhost X-Virus-Status: Clean X-Spam-Status: No, score=-4.1 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.0.4 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on terminus.zytor.com Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: Junio C Hamano wrote: > "H. Peter Anvin" writes: > >>If you have an ssh connection, you're writing over a pipe to the ssh >>process, and your local buffer is that pipe, which is PIPE_BUF size. > > I vaguely recall there was an interesting regression in recent > kernel history when the implementation of the pipe buffer was > changed, with which, writing the same amount of data with > different number of writes made things behave differently and > making the worst case buffer size less than traditional 4K. > > I wonder if we are going to be bitten by that one... > The definition of PIPE_BUF is that a write to a pipe of no more than PIPE_BUF bytes will either succeed immediately or block; it will not be broken up into multiple writes (with potential interlace problems.) It says *nothing* about what happens with multiple writes. -hpa