From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zheng Liu Subject: Re: ext4_fallocate Date: Mon, 2 Jul 2012 11:03:11 +0800 Message-ID: <20120702030310.GA2406@gmail.com> References: <20120625191744.GB9688@thunk.org> <4FE9B57F.4030704@redhat.com> <4FE9F9F4.7010804@zoho.com> <4FEA0DD1.8080403@gmail.com> <4FEA1415.8040809@redhat.com> <4FEA1F18.6010206@redhat.com> <20120627193034.GA3198@thunk.org> <4FEB9115.6090309@redhat.com> <4FEC3FAA.1060503@redhat.com> <27810AD9-FEA3-4C82-A5EC-A4B9B5F90071@dilger.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ric Wheeler , Eric Sandeen , Theodore Ts'o , Fredrick , linux-ext4@vger.kernel.org, wenqing.lz@taobao.com To: Andreas Dilger Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:46243 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932118Ab2GBCyz (ORCPT ); Sun, 1 Jul 2012 22:54:55 -0400 Received: by pbbrp8 with SMTP id rp8so6933280pbb.19 for ; Sun, 01 Jul 2012 19:54:55 -0700 (PDT) Content-Disposition: inline In-Reply-To: <27810AD9-FEA3-4C82-A5EC-A4B9B5F90071@dilger.ca> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Jun 29, 2012 at 01:02:35PM -0600, Andreas Dilger wrote: > There is already code for this in the ext4 uninit extent handling. > Currently the limit is 15(?) blocks, to inflate the write size up > to zero-fill a 64kB chunk on 4kB blocksize filesystems. I wouldn't > object to increasing this to zero out a full 1MB (aligned) chunk > under random IO cases. I agree with you that we can increase it to 1MB chunk, and I will run some tests to see the result. In addition, I am thinking whether we can provide a parameter in sysfs or some other places to adjust this value dynamically. Regards, Zheng