From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751449Ab1KYFnA (ORCPT ); Fri, 25 Nov 2011 00:43:00 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:60951 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751081Ab1KYFm7 (ORCPT ); Fri, 25 Nov 2011 00:42:59 -0500 Message-ID: <4ECF2AD3.5050801@gmail.com> Date: Fri, 25 Nov 2011 13:42:43 +0800 From: Wang Sheng-Hui User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.18) Gecko/20110617 Thunderbird/3.1.11 MIME-Version: 1.0 To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mel@csn.ul.ie Subject: Question about mm/compaction.c/acct_isolated: computing nr_anon, nr_file Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Why does it double the number in line 233/234? 222/* Update the number of anon and file isolated pages in the zone */ 223static void acct_isolated(struct zone *zone, struct compact_control *cc) 224{ 225 struct page *page; 226 unsigned int count[NR_LRU_LISTS] = { 0, }; 227 228 list_for_each_entry(page, &cc->migratepages, lru) { 229 int lru = page_lru_base_type(page); 230 count[lru]++; 231 } 232 233 cc->nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; 234 cc->nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; 235 __mod_zone_page_state(zone, NR_ISOLATED_ANON, cc->nr_anon); 236 __mod_zone_page_state(zone, NR_ISOLATED_FILE, cc->nr_file); 237} thanks,