From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ea0-f178.google.com (mail-ea0-f178.google.com [209.85.215.178]) by kanga.kvack.org (Postfix) with ESMTP id A12AF6B0031 for ; Wed, 15 Jan 2014 19:17:00 -0500 (EST) Received: by mail-ea0-f178.google.com with SMTP id d10so801362eaj.23 for ; Wed, 15 Jan 2014 16:17:00 -0800 (PST) Received: from jenni2.inet.fi (mta-out.inet.fi. [195.156.147.13]) by mx.google.com with ESMTP id r9si10876265eeo.65.2014.01.15.16.16.59 for ; Wed, 15 Jan 2014 16:16:59 -0800 (PST) Date: Thu, 16 Jan 2014 02:16:54 +0200 From: "Kirill A. Shutemov" Subject: Re: [RFC][PATCH 3/9] mm: page->pfmemalloc only used by slab/skb Message-ID: <20140116001654.GB8456@node.dhcp.inet.fi> References: <20140114180042.C1C33F78@viggo.jf.intel.com> <20140114180051.0181E467@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140114180051.0181E467@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, penberg@kernel.org, cl@linux-foundation.org On Tue, Jan 14, 2014 at 10:00:51AM -0800, Dave Hansen wrote: > > From: Dave Hansen > > page->pfmemalloc does not deserve a spot in 'struct page'. It is > only used transiently _just_ after a page leaves the buddy > allocator. > > Instead of declaring a union, we move its functionality behind a > few quick accessor functions. This way we could also much more > easily audit that it is being used correctly in debugging > scenarios. For instance, we could store a magic number in there > which could never get reused as a page->index and check that the > magic number exists in page_pfmemalloc(). > > Signed-off-by: Dave Hansen Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org