From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750816Ab3HSNkn (ORCPT ); Mon, 19 Aug 2013 09:40:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60277 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750707Ab3HSNkm (ORCPT ); Mon, 19 Aug 2013 09:40:42 -0400 Date: Mon, 19 Aug 2013 09:40:39 -0400 From: Mike Snitzer To: Frank Mayhar , linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: Re: dm: Make MIN_IOS, et al, tunable via sysctl. Message-ID: <20130819134038.GA27167@redhat.com> References: <1376070533.26057.244.camel@bobble.lax.corp.google.com> <20130817123039.GR1762@agk-dp.fab.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130817123039.GR1762@agk-dp.fab.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 17 2013 at 8:30am -0400, Alasdair G Kergon wrote: > On Fri, Aug 16, 2013 at 03:55:21PM -0700, Frank Mayhar wrote: > > This patch fixes that by changing the hardcoded MIN_IOS (and certain > > other) #defines in dm-crypt, dm-io, dm-mpath, dm-snap and dm itself to > > sysctl-modifiable values. This lets us change the size of these pools > > on the fly, we can reduce the size of the pools and reduce memory > > pressure. > > Did you consider using module_param_named()? > (E.g. dm_verity_prefetch_cluster in dm-verity.) Right, I'd prefer to see this be implemented in terms of module_param_named(). Aside from dm-verity, dm-bufio.c makes the most use of it. Mike