From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263762AbTLEACd (ORCPT ); Thu, 4 Dec 2003 19:02:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263763AbTLEACc (ORCPT ); Thu, 4 Dec 2003 19:02:32 -0500 Received: from dsl092-053-140.phl1.dsl.speakeasy.net ([66.92.53.140]:901 "EHLO grelber.thyrsus.com") by vger.kernel.org with ESMTP id S263762AbTLEACb (ORCPT ); Thu, 4 Dec 2003 19:02:31 -0500 From: Rob Landley Reply-To: rob@landley.net To: Szakacsits Szabolcs Subject: Re: Is there a "make hole" (truncate in middle) syscall? Date: Thu, 4 Dec 2003 18:02:52 -0600 User-Agent: KMail/1.5 Cc: linux-kernel@vger.kernel.org References: <200312041432.23907.rob@landley.net> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200312041802.52067.rob@landley.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 04 December 2003 15:10, Szakacsits Szabolcs wrote: > On Thu, 4 Dec 2003, Rob Landley wrote: > > What are the downsides of holes? [...] is there a performance penalty to > > having a file with 1000 4k holes in it, etc...) > > Depends what you do, what fs you use. Using XFS XFS_IOC_GETBMAPX you might > get a huge improvement, see e.g. some numbers, > > http://marc.theaimsgroup.com/?l=reiserfs&m=105827549109079&w=2 > > The problem is, 0 general purpose (like cp, tar, cat, etc) util supports > it, you have to code your app accordingly. Okay, I'll bite. How would one go about adding hole support to cat? :) Adding hole support to busybox's cp and tar is on my to-do list. (Pretty far down on the list, but still...) > Szaka Rob