From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751388AbXC3Nzc (ORCPT ); Fri, 30 Mar 2007 09:55:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751789AbXC3Nzc (ORCPT ); Fri, 30 Mar 2007 09:55:32 -0400 Received: from nz-out-0506.google.com ([64.233.162.236]:32645 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388AbXC3Nzb (ORCPT ); Fri, 30 Mar 2007 09:55:31 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:subject:content-type:content-transfer-encoding; b=LTMFrzLD5Q5yECQSoiPe8wOF8ElXEWVogxgNi9cdClKgv5Zo1vOtNK9QpX8fNJBiG6WlyMsle6grB1Lhgip/ZOZ62osa276LI9pdbqDxJS5nJfchIoU+eo4pLRW11m2sl/ztiK/m4UgmytGKHJgRqc+XIyU081vDYi8UiV7Y2NQ= Message-ID: <460D16CC.2070708@gmail.com> Date: Fri, 30 Mar 2007 21:55:24 +0800 From: Bin Chen User-Agent: Thunderbird 1.5.0.9 (X11/20070103) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: What is the active page in Linux kernel, so inactive? Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I am quite confusing about the concept that Linux usage of the term active and inactive pages. Some book tells me active pages is the 'working set' in system, but what is the 'working set'? There is a page cache system in the system, and when a page is freed when not needed by some way, the page will first considered be added to the page cache. Once some stuff need more pages, it also get it from page cache. So it is easy to understand that there is two list in the page cache, one for 'used' pages, that is, the page actually used by some one. And the other one is 'unused', that is, unused by any one but is still cached. But I doubt whether the 'used' and 'unused' correspond to active and inactive correctly? If I am right, when the system memory is tight, the pages in the active list will be swapped out and the pages will be added to the inactive list? Or the pages that has swapped out go directly to the buddy allocator? Thanks in advance. abai