From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753144Ab3HQMao (ORCPT ); Sat, 17 Aug 2013 08:30:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54433 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752917Ab3HQMam (ORCPT ); Sat, 17 Aug 2013 08:30:42 -0400 Date: Sat, 17 Aug 2013 13:30:39 +0100 From: Alasdair G Kergon To: Frank Mayhar Cc: linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: Re: [dm-devel] [PATCH] dm: Make MIN_IOS, et al, tunable via sysctl. Message-ID: <20130817123039.GR1762@agk-dp.fab.redhat.com> Mail-Followup-To: Frank Mayhar , linux-kernel@vger.kernel.org, dm-devel@redhat.com References: <1376070533.26057.244.camel@bobble.lax.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1376070533.26057.244.camel@bobble.lax.corp.google.com> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: 64 Baker Street, 4th floor, London, W1U 7DF. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.) Alasdair