Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765778AbXEWTRe (ORCPT ); Wed, 23 May 2007 15:17:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756164AbXEWTRX (ORCPT ); Wed, 23 May 2007 15:17:23 -0400 Received: from mail-gw3.adaptec.com ([216.52.22.36]:55487 "EHLO mail-gw3.adaptec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756173AbXEWTRW convert rfc822-to-8bit (ORCPT ); Wed, 23 May 2007 15:17:22 -0400 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message Subject: RE: [PATCH] [scsi] Remove __GFP_DMA MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 8BIT Date: Wed, 23 May 2007 15:17:08 -0400 Message-ID: In-reply-to: <1179933494.3700.16.camel@mulgrave.il.steeleye.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH] [scsi] Remove __GFP_DMA Thread-Index: AcedTjUWC94ku7uJQvyyMCq8TAc5OwAIDuKA References: <20070521151525.GA581@suse.de> <6d6a94c50705221941y63f4db7bj174a2265d9eaa61a@mail.gmail.com> <1179933494.3700.16.camel@mulgrave.il.steeleye.com> From: "Salyzyn, Mark" To: "James Bottomley" , "Aubrey Li" Cc: "Christoph Lameter" , "Bernhard Walle" , , "Andrew Morton" , Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2124 Lines: 59 The 31 bit limit for some of these cards is a problem, we currently only do __GFP_DMA for bounce buffer sg elements allocated for user supplied references in ioctls. I figure we should be using pci_alloc_consistent calls for these allocations to more accurately acquire memory within the 31 bit limit if necessary, we could switch to these to remove the need for the __GFP_DMA flag in the aacraid driver? -- Mark -----Original Message----- From: linux-scsi-owner@vger.kernel.org [mailto:linux-scsi-owner@vger.kernel.org] On Behalf Of James Bottomley Sent: Wednesday, May 23, 2007 11:18 AM To: Aubrey Li Cc: Christoph Lameter; Bernhard Walle; linux-scsi@vger.kernel.org; Andrew Morton; linux-kernel@vger.kernel.org Subject: Re: [PATCH] [scsi] Remove __GFP_DMA On Wed, 2007-05-23 at 10:41 +0800, Aubrey Li wrote: > On 5/23/07, Christoph Lameter wrote: > > On Mon, 21 May 2007, Bernhard Walle wrote: > > > > > [PATCH] [scsi] Remove __GFP_DMA > > > > > > After 821de3a27bf33f11ec878562577c586cd5f83c64, it's not necessary to alloate a > > > DMA buffer any more in sd.c. > > > > > > Signed-off-by: Bernhard Walle > > > > Great that avoids a DMA kmalloc slab. Any other GFP_DMAs left in the scsi > > layer? > > > > Acked-by: Christoph Lameter > > Yes, here is another patch I'll defer to Mark on this one. However, please remember that you can't just blindly remove GFP_DMA ... there are some cards which require it. Aacraid is one example ... it has a set of cards that can only DMA to 31 bits. For them, the GFP_DMA is necessary: The allocation in question is a scatterlist, which must be within the device DMA mask. James - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/