From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id DC24A6B02A4 for ; Sun, 25 Jul 2010 13:03:09 -0400 (EDT) Received: by iwn2 with SMTP id 2so2462482iwn.14 for ; Sun, 25 Jul 2010 10:03:08 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1280066561-8543-1-git-send-email-minchan.kim@gmail.com> References: <1280066561-8543-1-git-send-email-minchan.kim@gmail.com> Date: Sun, 25 Jul 2010 22:33:08 +0530 Message-ID: Subject: Re: [PATCH] Tight check of pfn_valid on sparsemem - v3 From: Balbir Singh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: Andrew Morton , linux-mm , linux-arm-kernel , LKML , Kukjin Kim , KAMEZAWA Hiroyuki , Mel Gorman , Johannes Weiner , Russell King List-ID: On Sun, Jul 25, 2010 at 7:32 PM, Minchan Kim wrote: > Changelog since v2 > =A0o Change some function names > =A0o Remove mark_memmap_hole in memmap bring up > =A0o Change CONFIG_SPARSEMEM with CONFIG_ARCH_HAS_HOLES_MEMORYMODEL > > I have a plan following as after this patch is acked. > > TODO: > 1) expand pfn_valid to FALTMEM in ARM > I think we can enhance pfn_valid of FLATMEM in ARM. > Now it is doing binary search and it's expesive. > First of all, After we merge this patch, I expand it to FALTMEM of ARM. > > 2) remove memmap_valid_within > We can remove memmap_valid_within by strict pfn_valid's tight check. > > 3) Optimize hole check in sparsemem > In case of spasemem, we can optimize pfn_valid through defining new flag > like SECTION_HAS_HOLE of hole mem_section. > Is there an assumption somewhere that assumes that page->private will always have MEMMAP_HOLE set when the pfn is invalid, independent of the context in which it is invoked? BTW, I'd also recommend moving over to using set_page_private() and page_private() wrappers (makes the code easier to search) Balbir -- 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