From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 1 Mar 2007 19:59:43 -0800 From: Andrew Morton Subject: Re: The performance and behaviour of the anti-fragmentation related patches Message-Id: <20070301195943.8ceb221a.akpm@linux-foundation.org> In-Reply-To: References: <20070301101249.GA29351@skynet.ie> <20070301160915.6da876c5.akpm@linux-foundation.org> <45E7835A.8000908@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: Balbir Singh , Mel Gorman , npiggin@suse.de, clameter@engr.sgi.com, mingo@elte.hu, jschopp@austin.ibm.com, arjan@infradead.org, mbligh@mbligh.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Thu, 1 Mar 2007 19:44:27 -0800 (PST) Linus Torvalds wrote: > In other words, I really don't see a huge upside. I see *lots* of > downsides, but upsides? Not so much. Almost everybody who wants unplug > wants virtualization, and right now none of the "big virtualization" > people would want to have kernel-level anti-fragmentation anyway sicne > they'd need to do it on their own. Agree with all that, but you're missing the other application: power saving. FBDIMMs take eight watts a pop. If we can turn them off when the system is unloaded we save either four or all eight watts (assuming we can get Intel to part with the information which is needed to do this. I fear an ACPI method will ensue). There's a whole lot of complexity and work in all of this, but 24*8 watts is a lot of watts, and it's worth striving for. -- 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