From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phillip Susi Subject: Re: ext4_fallocate Date: Thu, 28 Jun 2012 11:12:15 -0400 Message-ID: <4FEC744F.6010901@ubuntu.com> References: <4FE8086F.4070506@zoho.com> <13363B8E-7411-4AA3-8835-F9DEF67B2ABE@dilger.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Fredrick , linux-ext4@vger.kernel.org To: Andreas Dilger Return-path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120]:5337 "EHLO cdptpa-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754381Ab2F1PMT (ORCPT ); Thu, 28 Jun 2012 11:12:19 -0400 In-Reply-To: <13363B8E-7411-4AA3-8835-F9DEF67B2ABE@dilger.ca> Sender: linux-ext4-owner@vger.kernel.org List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 6/25/2012 3:33 AM, Andreas Dilger wrote: > There was a recent patch series "ext4: add an io-tree to track > block allocation" that may improve the performance for your case of > overwrite of uninitialized files, but it hasn't landed yet. I'm confused. Why is writing to uninitialized extents slow, and why would this help? If you have an uninitialized extent, then the blocks are already allocated, just flagged as containing uninitialized data. Writing to them should be no different than writing to initialized extents, save for the step of clearing the uninitialized flag. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJP7HROAAoJEJrBOlT6nu75nb8IANw0fBczdWvuO7Ne/Xi6uYjY 0RUoAlsEsdmHy8Gjc7aZK0f6Qlf/pC2YQanNeMCE9DdxHEc83ibBA1jppjk1oFQ4 Qq2+lX+UNP3xsvPnB6NyH6nZNY+rZGHceDksSVZySAzdN+HCwdiBlByEXMLY7iY3 AuAm5mWPlRT34yY8/YZhs4OmlKW7FaAHxetRpj9GyobRfkqFK8EcbpXp/7iAon87 dSj4QXdQoFx6fVF1wEhCbzxrmMs+R3wpfIuqnNJwSfiunND0JYQGMC/GuSKveD0R Gn9Xd9XkNK6JXWNdGdMiGU2+R2FMjRdW1igcgkrOXd5tEUGYKjeUIwTiIclp5VY= =N44C -----END PGP SIGNATURE-----