From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932136Ab1EYHYN (ORCPT ); Wed, 25 May 2011 03:24:13 -0400 Received: from mtagate2.uk.ibm.com ([194.196.100.162]:50661 "EHLO mtagate2.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754041Ab1EYHYL (ORCPT ); Wed, 25 May 2011 03:24:11 -0400 Date: Wed, 25 May 2011 09:24:07 +0200 From: Heiko Carstens To: David Rientjes Cc: Martin Schwidefsky , Pekka Enberg , Christoph Lameter , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/6] s390, block: disable fixed buffer mode when DMA support is disabled Message-ID: <20110525072407.GB2498@osiris.boeblingen.de.ibm.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Tue, May 24, 2011 at 04:53:45PM -0700, David Rientjes wrote: > dasd=fixedbuffers must create a SLAB_CACHE_DMA cache, which is not > possible if CONFIG_ZONE_DMA is disabled (a supported configuration > without 64-bit support). > > If passed, emit a warning and disable fixed buffer mode. > > Signed-off-by: David Rientjes What's the reasoning here? On s390 for !CONFIG_64BIT ZONE_DMA would be equal to ZONE_NORMAL, that's why we only have ZONE_NORMAL. So I don't see that something wouldn't work... > --- > drivers/s390/block/dasd_devmap.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c > --- a/drivers/s390/block/dasd_devmap.c > +++ b/drivers/s390/block/dasd_devmap.c > @@ -282,6 +282,11 @@ dasd_parse_keyword( char *parsestring ) { > return residual_str; > } > if (strncmp("fixedbuffers", parsestring, length) == 0) { > +#ifndef CONFIG_ZONE_DMA > + DBF_EVENT(DBF_WARNING, "%s", "DMA support disabled, " > + "fixed buffer mode disabled."); > + return residual_str; > +#endif > if (dasd_page_cache) > return residual_str; > dasd_page_cache =