From: Florian Weimer Subject: Re: Is TRIM/DISCARD going to be a performance problem? Date: Fri, 29 May 2009 12:52:21 +0200 Message-ID: <82k540dvve.fsf@mid.bfk.de> References: <20090511081216.GK4694@kernel.dk> <20090511084121.GB29082@mit.edu> <1242062325.9647.4.camel@localhost.localdomain> <20090511184323.GA16885@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Chris Mason , Theodore Tso , Jens Axboe , Ric Wheeler , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org To: Matthew Wilcox Return-path: Received: from mx01.bfk.de ([193.227.124.2]:52891 "EHLO mx01.bfk.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757421AbZE2LFW convert rfc822-to-8bit (ORCPT ); Fri, 29 May 2009 07:05:22 -0400 In-Reply-To: <20090511184323.GA16885@linux.intel.com> (Matthew Wilcox's message of "Mon\, 11 May 2009 11\:43\:23 -0700") Sender: linux-ext4-owner@vger.kernel.org List-ID: * Matthew Wilcox: > Actually, that's the exact opposite of what you want. You want to tr= y > to reuse blocks that are scheduled for trimming so that we never have= to > send the command at all. I thought that the device would receive as many TRIM commands as possible, to aid its internal reorganization process? A write which overwrites a whole block could be equivalent, but it may not be a good idea to artificially increase I/O traffic to turn partial writes to unused blocks into full-block writes. --=20 =46lorian Weimer BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstra=DFe 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html