Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756634AbZJ0I6O (ORCPT ); Tue, 27 Oct 2009 04:58:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932124AbZJ0I6N (ORCPT ); Tue, 27 Oct 2009 04:58:13 -0400 Received: from vpn.id2.novell.com ([195.33.99.129]:24431 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756589AbZJ0I6N convert rfc822-to-8bit (ORCPT ); Tue, 27 Oct 2009 04:58:13 -0400 Message-Id: <4AE6C436020000780001BF10@vpn.id2.novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.1 Date: Tue, 27 Oct 2009 08:58:14 +0000 From: "Jan Beulich" To: , "FUJITA Tomonori" Cc: , , , , , Subject: Re: [PATCH] x86: adjust GFP mask handling for coherent allocations References: <20091026152246.GB3749@elte.hu> <4AE5D238020000780001BD46@vpn.id2.novell.com> <20091026201917.GE24682@elte.hu> <20091027103758L.fujita.tomonori@lab.ntt.co.jp> In-Reply-To: <20091027103758L.fujita.tomonori@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1449 Lines: 33 >>> FUJITA Tomonori 27.10.09 02:38 >>> >On Mon, 26 Oct 2009 21:19:17 +0100 >Ingo Molnar wrote: >> Well, can ISA_BIT_MASK fall back to DMA_BIT_MASK(32) on !CONFIG_ISA? If >> we have ISA support disabled we might as well pretend the whole world is >> PCI, right? > >I don't think that it works. At least, you can't do that with >the DMA_BIT_MASK(24) in arch/x86/kernl/pci-dma.c; it must be >DMA_BIT_MASK(24) even with !CONFIG_ISA. This one I too was about to point out, which is why I think DMA_ISA_BIT_MASK should only be an alias of DMA_BIT_MASK(24), with no fallback to DMA_BIT_MASK(32). >> That way we'd get rid of that #ifdef in the .c code too. > >Well, in the first place, we don't need the #ifdef in Jan's patch. We >can always use DMA_BIT_MASK(24) for the fallback device. But this one I don't agree with - the purpose of the patch is to not have a 24-bit (or 32-bit) mask here unconditionally: It would result in GFP_DMA to be forced on for the allocation (which the patch specifically eliminates), and for x86-64 this wasn't the case up to .25, which is the behavior I'm trying to restore (and extend to the !CONFIG_ISA case for ix86). Jan -- 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/