From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id B2E006B01F0 for ; Tue, 17 Aug 2010 07:04:41 -0400 (EDT) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o7HB4duS020405 for (envelope-from iram.shahzad@jp.fujitsu.com); Tue, 17 Aug 2010 20:04:39 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 7808545DE4F for ; Tue, 17 Aug 2010 20:04:39 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 5756645DE4E for ; Tue, 17 Aug 2010 20:04:39 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 3FE101DB8040 for ; Tue, 17 Aug 2010 20:04:39 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id F27281DB803C for ; Tue, 17 Aug 2010 20:04:38 +0900 (JST) Message-ID: <325E0A25FE724BA18190186F058FF37E@rainbow> From: "Iram Shahzad" Subject: compaction: trying to understand the code Date: Tue, 17 Aug 2010 20:08:54 +0900 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-15"; reply-type=response Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: linux-mm@kvack.org List-ID: Hi I am trying to understand the following code in isolate_migratepages function. I have a question regarding this. --- while (unlikely(too_many_isolated(zone))) { congestion_wait(BLK_RW_ASYNC, HZ/10); if (fatal_signal_pending(current)) return 0; } --- I have seen that in some cases this while loop never exits because too_many_isolated keeps returning true for ever. And hence the process hangs. Is this intended behaviour? What is it that is supposed to change the "too_many_isolated" situation? In other words, what is it that is supposed to increase the "inactive" or decrease the "isolated" so that isolated > inactive becomes false? Best regards Iram -- 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