From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755344Ab2JCFAX (ORCPT ); Wed, 3 Oct 2012 01:00:23 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:59717 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752928Ab2JCFAW (ORCPT ); Wed, 3 Oct 2012 01:00:22 -0400 Date: Tue, 2 Oct 2012 22:00:19 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Glauber Costa cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Christoph Lameter , Mel Gorman Subject: Re: [PATCH] make GFP_NOTRACK flag unconditional In-Reply-To: <1348826194-21781-1-git-send-email-glommer@parallels.com> Message-ID: References: <1348826194-21781-1-git-send-email-glommer@parallels.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 28 Sep 2012, Glauber Costa wrote: > There was a general sentiment in a recent discussion (See > https://lkml.org/lkml/2012/9/18/258) that the __GFP flags should be > defined unconditionally. Currently, the only offender is GFP_NOTRACK, > which is conditional to KMEMCHECK. > > This simple patch makes it unconditional. > > Signed-off-by: Glauber Costa > CC: Christoph Lameter > CC: Mel Gorman > CC: Andrew Morton Acked-by: David Rientjes I think it was done this way to show that if CONFIG_KMEMCHECK=n then the bit could be reused for something else but I can't think of any reason why that would be useful; what would need to add a gfp bit that would also happen to depend on CONFIG_KMEMCHECK=n? Nothing comes to mind to save a bit. There are other cases of this as well, like __GFP_OTHER_NODE which is only useful for thp and it's defined unconditionally. So this seems fine to me.