From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id 5798E6B002C for ; Tue, 18 Oct 2011 14:00:41 -0400 (EDT) Received: by pzd13 with SMTP id 13so2389120pzd.6 for ; Tue, 18 Oct 2011 11:00:38 -0700 (PDT) Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Subject: Re: [PATCH 2/9] mm: alloc_contig_freed_pages() added References: <1317909290-29832-1-git-send-email-m.szyprowski@samsung.com> <1317909290-29832-3-git-send-email-m.szyprowski@samsung.com> <20111018122109.GB6660@csn.ul.ie> <1318960126.4465.249.camel@nimitz> Date: Tue, 18 Oct 2011 11:00:34 -0700 MIME-Version: 1.0 Content-Transfer-Encoding: Quoted-Printable From: "Michal Nazarewicz" Message-ID: In-Reply-To: <1318960126.4465.249.camel@nimitz> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Marek Szyprowski , Mel Gorman , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org, Kyungmin Park , Russell King , Andrew Morton , KAMEZAWA Hiroyuki , Ankita Garg , Daniel Walker , Arnd Bergmann , Jesse Barker , Jonathan Corbet , Shariq Hasnain , Chunsang Jeong On Tue, 18 Oct 2011 10:48:46 -0700, Dave Hansen wrote: > On Tue, 2011-10-18 at 10:26 -0700, Michal Nazarewicz wrote: >> > You can do this in a more general fashion by checking the >> > zone boundaries and resolving the pfn->page every MAX_ORDER_NR_PAGE= S. >> > That will not be SPARSEMEM specific. >> >> I've tried doing stuff that way but it ended up with much more code. > > I guess instead of: > >>> +static inline bool zone_pfn_same_memmap(unsigned long pfn1, unsigne= d long pfn2) >>> +{ >>> + return pfn_to_section_nr(pfn1) =3D=3D pfn_to_section_nr(pfn2); >>> +} > > You could do: > > static inline bool zone_pfn_same_maxorder(unsigned long pfn1, unsigned= long pfn2) > { > unsigned long mask =3D MAX_ORDER_NR_PAGES-1; > return (pfn1 & mask) =3D=3D (pfn2 & mask); > } > > I think that works. Should be the same code you have now, basically. Makes sense. It'd require calling pfn_to_page() every MAX_ORDER_NR_PAGE= S even in memory models that have linear mapping of struct page, but I guess th= at's not that bad. -- = Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=3D./ `o ..o | Computer Science, Micha=C5=82 =E2=80=9Cmina86=E2=80=9D Nazarewicz= (o o) ooo +------------------ooO--(_)--Ooo-- -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org