From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754063Ab1AXSsG (ORCPT ); Mon, 24 Jan 2011 13:48:06 -0500 Received: from e9.ny.us.ibm.com ([32.97.182.139]:34640 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753562Ab1AXSsE (ORCPT ); Mon, 24 Jan 2011 13:48:04 -0500 Subject: Re: [PATCH] ARM: mm: Regarding section when dealing with meminfo From: Dave Hansen To: Russell King - ARM Linux Cc: KyongHo Cho , Kukjin Kim , KeyYoung Park , linux-kernel@vger.kernel.org, Ilho Lee , linux-mm@kvack.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org In-Reply-To: <20110124175807.GA27427@n2100.arm.linux.org.uk> References: <1295516739-9839-1-git-send-email-pullip.cho@samsung.com> <1295544047.9039.609.camel@nimitz> <20110120180146.GH6335@n2100.arm.linux.org.uk> <1295547087.9039.694.camel@nimitz> <20110123180532.GA3509@n2100.arm.linux.org.uk> <1295887937.11047.119.camel@nimitz> <20110124175807.GA27427@n2100.arm.linux.org.uk> Content-Type: text/plain; charset="ANSI_X3.4-1968" Date: Mon, 24 Jan 2011 10:47:37 -0800 Message-ID: <1295894857.11047.556.camel@nimitz> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-01-24 at 17:58 +0000, Russell King - ARM Linux wrote: > Wrong. For flatmem, we have a pfn_valid() which is backed by doing a > one, two or maybe rarely three compare search of the memblocks. Short > of having a bitmap of every page in the 4GB memory space, you can't > get more efficient than that. Sweet. So, we can just take the original patch that started this conversation, add the requisite pfn_valid()s and pfn_to_page()s, and skip the sparsemem #ifdefs. Right? -- Dave