From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <20040204191829.57468.qmail@web9704.mail.yahoo.com> Date: Wed, 4 Feb 2004 11:18:29 -0800 (PST) From: Alok Mooley Subject: Re: Active Memory Defragmentation: Our implementation & problems In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: root@chaos.analogic.com Cc: linux-kernel , linux-mm , Dave Hansen List-ID: --- "Richard B. Johnson" > If this is an Intel x86 machine, it is impossible > for pages > to get fragmented in the first place. The hardware > allows any > page, from anywhere in memory, to be concatenated > into linear > virtual address space. Even the kernel address space > is virtual. > The only time you need physically-adjacent pages is > if you > are doing DMA that is more than a page-length at a > time. The > kernel keeps a bunch of those pages around for just > that > purpose. > > So, if you are making a "memory defragmenter", it is > a CPU time-sink. > That's all. What if the external fragmentation increases so much that it is not possible to find a large sized block? Then, is it not better to defragment rather than swap or fail? -Alok __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free web site building tool. Try it! http://webhosting.yahoo.com/ps/sb/ -- 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: aart@kvack.org