Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753721Ab1FJJNN (ORCPT ); Fri, 10 Jun 2011 05:13:13 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:49812 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750774Ab1FJJNM (ORCPT ); Fri, 10 Jun 2011 05:13:12 -0400 Date: Fri, 10 Jun 2011 10:12:33 +0100 From: Russell King - ARM Linux To: Dmitry Eremin-Solenikov Cc: Andrew Morton , KOSAKI Motohiro , tglx@linutronix.de, rientjes@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mel@csn.ul.ie, kamezawa.hiroyu@jp.fujitsu.com, riel@redhat.com, pavel@ucw.cz Subject: Re: [PATCH] Make GFP_DMA allocations w/o ZONE_DMA emit a warning instead of failing Message-ID: <20110610091233.GJ24424@n2100.arm.linux.org.uk> References: <20110601181918.GO3660@n2100.arm.linux.org.uk> <4DF1C9DE.4070605@jp.fujitsu.com> <20110610004331.13672278.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1303 Lines: 29 On Fri, Jun 10, 2011 at 12:11:42PM +0400, Dmitry Eremin-Solenikov wrote: > On 6/10/11, Andrew Morton wrote: > > On Fri, 10 Jun 2011 16:38:06 +0900 KOSAKI Motohiro > > wrote: > > > >> Subject: [PATCH] Revert "mm: fail GFP_DMA allocations when ZONE_DMA is not > >> configured" > > > > Confused. We reverted this over a week ago. > > Should one submit a patch adding a warning to GFP_DMA allocations > w/o ZONE_DMA, or the idea of the original patch is wrong? Linus was far from impressed by the original commit, saying: | Using GFP_DMA is reasonable in a driver - on platforms where that | matters, it should allocate from the DMA zone, on platforms where it | doesn't matter it should be a no-op. So no, not even a warning. What is a useful exercise though is to remove GFP_DMA from those allocations which should never have had GFP_DMA added - such as those used for data structures which have nothing to do with DMA at all. Also dma_alloc_coherent() should not be given GFP_DMA in any case. -- 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/