From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:55385 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753707AbaCNUqf (ORCPT ); Fri, 14 Mar 2014 16:46:35 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1WOYzy-0001wD-EN for linux-btrfs@vger.kernel.org; Fri, 14 Mar 2014 21:46:34 +0100 Received: from p5b005895.dip0.t-ipconnect.de ([91.0.88.149]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 14 Mar 2014 21:46:34 +0100 Received: from holger.hoffstaette by p5b005895.dip0.t-ipconnect.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 14 Mar 2014 21:46:34 +0100 To: linux-btrfs@vger.kernel.org From: Holger =?iso-8859-1?q?Hoffst=E4tte?= Subject: Re: discard synchronous on most SSDs? Date: Fri, 14 Mar 2014 20:46:09 +0000 (UTC) Message-ID: References: <1756989.4ep0Vdupld@tethys> <20140309113350.GH6318@carfax.org.uk> <20140314021159.GQ18959@merlins.org> <20140314051750.GY6143@merlins.org> <531C1CC4.701@gmail.com> <20140314051750.GY6143@merlins.org> <5289248.oqpgSKG6td@quad> <20140314192605.GD6143@merlins.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, 14 Mar 2014 15:57:41 -0400, Martin K. Petersen wrote: > So right now I'm afraid we don't have a good way for a user to determine > whether a device supports queued trims or not. Mount with discard, unpack kernel tree, sync, rm -rf tree. If it takes several seconds, you have sync discard, no? This changed somewhere around kernel 3.8.x; before that it used to be acceptably fast. Since then I only do batch trims, daily (server) or weekly (laptop). -h