From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756894AbYJKQE3 (ORCPT ); Sat, 11 Oct 2008 12:04:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753616AbYJKQEU (ORCPT ); Sat, 11 Oct 2008 12:04:20 -0400 Received: from casper.infradead.org ([85.118.1.10]:42020 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753599AbYJKQET (ORCPT ); Sat, 11 Oct 2008 12:04:19 -0400 Date: Sat, 11 Oct 2008 09:04:07 -0700 From: Arjan van de Ven To: James Bottomley Cc: Jens Axboe , Alan Cox , Linux Kernel Mailing List , linux-ide@vger.kernel.org, torvalds@osdl.org Subject: Re: libata: set queue SSD flag for SSD devices Message-ID: <20081011090407.6de9b8b4@infradead.org> In-Reply-To: <1223739853.4159.17.camel@localhost.localdomain> References: <200810101904.m9AJ42Gq018897@hera.kernel.org> <20081010202515.446857cc@lxorguk.ukuu.org.uk> <20081010200528.GJ19428@kernel.dk> <20081010175508.3d1ed2a4@infradead.org> <1223710417.4159.11.camel@localhost.localdomain> <20081011140600.GR19428@kernel.dk> <1223739853.4159.17.camel@localhost.localdomain> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 11 Oct 2008 17:44:13 +0200 James Bottomley wrote: > > > So we need something a bit more involved, but not too complex. A > > fine line... > > It's a policy ... just let userspace do it so the user can tune it. > That's what EMC does now (except I think they key of inquiry strings > rather than cache size). while the chosen elevator obviously is policy, the kernel really should pick a sensible default based on what it knows. Lets put it this way: if userland needs to do a tuning to the kernel based on data only provided by the kernel, and will always do it the same way, we should have made that choice the default policy in the kernel in the first place. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org