Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752697AbZJ0Jrb (ORCPT ); Tue, 27 Oct 2009 05:47:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752181AbZJ0Jra (ORCPT ); Tue, 27 Oct 2009 05:47:30 -0400 Received: from vpn.id2.novell.com ([195.33.99.129]:28950 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751639AbZJ0Jra convert rfc822-to-8bit (ORCPT ); Tue, 27 Oct 2009 05:47:30 -0400 Message-Id: <4AE6CFC4020000780001BF75@vpn.id2.novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.1 Date: Tue, 27 Oct 2009 09:47:32 +0000 From: "Jan Beulich" To: "FUJITA Tomonori" Cc: , , , , , , Subject: Re: [PATCH] x86: adjust GFP mask handling for coherent allocations References: <4AE6C4D3020000780001BF13@vpn.id2.novell.com> <20091027181053L.fujita.tomonori@lab.ntt.co.jp> <4AE6CA2A020000780001BF51@vpn.id2.novell.com> <20091027183658A.fujita.tomonori@lab.ntt.co.jp> In-Reply-To: <20091027183658A.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: 1401 Lines: 31 >>> FUJITA Tomonori 27.10.09 10:37 >>> >On Tue, 27 Oct 2009 09:23:38 +0000 >"Jan Beulich" wrote: > >> Because there's quite a few of them - just search for callers of >> dma_alloc_coherent() passing NULL as the first argument. Of course >> I'd rather see the fallback gone, but I think this requires cooperation >> from/action taken by the driver maintainers first. A first step might be >> to add a WRN_ON() for that case, but I don't see it being reasonable >> to eliminate the fallback right away. Hence, with it having got broken >> in .26 I think it is reasonable to fix it for the time being. > >Well, the most of them are drivers that nobody cares about (uses). > >What drivers did you hit this problem with? drivers/firmware/dell_rbu.c (on .27.x, and in particular with the derivation of __GFP_NORETRY from __GFP_DMA, which fortunately doesn't exist in newer kernels anymore). >We've lived with the current code for some years so this problem isn't >urgent at all. Please don't add another workaround for broken code. >Let's put WARN_ON for callers that use NULL and see who complains. 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/