From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261190AbVAMHcg (ORCPT ); Thu, 13 Jan 2005 02:32:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261198AbVAMHcf (ORCPT ); Thu, 13 Jan 2005 02:32:35 -0500 Received: from holomorphy.com ([207.189.100.168]:14306 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S261190AbVAMHbz (ORCPT ); Thu, 13 Jan 2005 02:31:55 -0500 Date: Wed, 12 Jan 2005 23:31:46 -0800 From: William Lee Irwin III To: Mel Gorman Cc: Linux Memory Management List , Linux Kernel Mailing List Subject: Re: [RFC] Avoiding fragmentation through different allocator Message-ID: <20050113073146.GB1226@holomorphy.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 12, 2005 at 09:09:24PM +0000, Mel Gorman wrote: > So... What the patch does. Allocations are divided up into three different > types of allocations; > UserReclaimable - These are userspace pages that are easily reclaimable. Right > now, I'm putting all allocations of GFP_USER and GFP_HIGHUSER as > well as disk-buffer pages into this category. These pages are trivially > reclaimed by writing the page out to swap or syncing with backing > storage > KernelReclaimable - These are pages allocated by the kernel that are easily > reclaimed. This is stuff like inode caches, dcache, buffer_heads etc. > These type of pages potentially could be reclaimed by dumping the > caches and reaping the slabs (drastic, but you get the idea). We could > also add pages into this category that are known to be only required > for a short time like buffers used with DMA > KernelNonReclaimable - These are pages that are allocated by the kernel that > are not trivially reclaimed. For example, the memory allocated for a > loaded module would be in this category. By default, allocations are > considered to be of this type I'd expect to do better with kernel/user discrimination only, having address-ordering biases in opposite directions for each case. -- wli