From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757200AbYCEQCf (ORCPT ); Wed, 5 Mar 2008 11:02:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754773AbYCEQCZ (ORCPT ); Wed, 5 Mar 2008 11:02:25 -0500 Received: from n29.bullet.mail.mud.yahoo.com ([68.142.200.152]:38568 "HELO n29.bullet.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754674AbYCEQCY (ORCPT ); Wed, 5 Mar 2008 11:02:24 -0500 X-Yahoo-Newman-Id: 282562.90815.bm@omp416.mail.mud.yahoo.com DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:From:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id; b=XpjGMY47icrpf2+ATK5HIOn1SzDfDQN1oOX3QoSAKXySrqHh8P+UA/PElIYd/UpSDRSohf0iNzODje8+te3CCrjHKJ4bEeyrcuGIaOkzu4qheVB7xHJSrJzU1GGLcACzoX6jz2zZvbPzme7m67U6TXhEjFRrAMCBF6ZysEB2W6I= ; X-YMail-OSG: In8m2NUVM1kQ9FU3byAQQgqxuywqKrCyPCr89OBX7k0AGTw41nwIEtdhSKi9Sj.o_HrMXB9dng-- X-Yahoo-Newman-Property: ymail-3 From: Nick Piggin To: "Ray Lee" Subject: Re: Are Linux pipes slower than the FreeBSD ones ? Date: Thu, 6 Mar 2008 03:02:06 +1100 User-Agent: KMail/1.9.5 Cc: "Eric Dumazet" , "David Miller" , dmantipov@yandex.ru, linux-kernel@vger.kernel.org References: <1389671204703217@webmail34.yandex.ru> <200803060238.39484.nickpiggin@yahoo.com.au> <2c0942db0803050755u7e17118h923328fb79ee206b@mail.gmail.com> In-Reply-To: <2c0942db0803050755u7e17118h923328fb79ee206b@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200803060302.07084.nickpiggin@yahoo.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 06 March 2008 02:55, Ray Lee wrote: > On Wed, Mar 5, 2008 at 7:38 AM, Nick Piggin wrote: > > Yeah, but why does the pipe inode need to have its times updated? > > I guess there is some reason... hopefully not C&P related. > > In principle so that the reader or writer can find out the last time > the other end did any processing of the pipe. And yeah, for POSIX > compliance: "Upon successful completion, pipe() will mark for update > the st_atime, st_ctime and st_mtime fields of the pipe. " Thanks. > But it'd be > nice if there were a way to avoid touching it more than once a second > (note the 'will mark for update' language). Or if the pipe is a > physical FIFO on a noatime filesystem? I doubt it really matters for anything except this test. I wouldn't bother doing anything fancy really. It just caught my eye and I was wondering why it was there at all. Thanks, Nick