From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id EABF96B01E3 for ; Sun, 11 Apr 2010 11:28:24 -0400 (EDT) Date: Sun, 11 Apr 2010 08:22:04 -0700 (PDT) From: Linus Torvalds Subject: Re: hugepages will matter more in the future In-Reply-To: <20100411115229.GB10952@elte.hu> Message-ID: References: <20100410194751.GA23751@elte.hu> <4BC0DE84.3090305@redhat.com> <4BC0E2C4.8090101@redhat.com> <4BC0E556.30304@redhat.com> <4BC19663.8080001@redhat.com> <4BC19916.20100@redhat.com> <20100411110015.GA10149@elte.hu> <4BC1B034.4050302@redhat.com> <20100411115229.GB10952@elte.hu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Ingo Molnar Cc: Avi Kivity , Jason Garrett-Glaser , Mike Galbraith , Andrea Arcangeli , Pekka Enberg , Andrew Morton , linux-mm@kvack.org, Marcelo Tosatti , Adam Litke , Izik Eidus , Hugh Dickins , Nick Piggin , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , Arnd Bergmann , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Arjan van de Ven List-ID: On Sun, 11 Apr 2010, Ingo Molnar wrote: > > Both Xorg, xterms and firefox have rather huge RSS's on my boxes. (Even a > phone these days easily has more than 512 MB RAM.) Andrea measured > multi-percent improvement in gcc performance. I think it's real. Reality check: he got multiple percent with - one huge badly written file being compiled that took 22s because it's such a horrible monster. - magic libc malloc flags tghat are totally and utterly unrealistic in anything but a benchmark - by basically keeping one CPU totally busy doing defragmentation. Quite frankly, that kind of "performance analysis" makes me _less_ interested rather than more. Because all it shows is that you're willing to do anything at all to get better numbers, regardless of whether it is _realistic_ or not. Seriously, guys. Get a grip. If you start talking about special malloc algorithms, you have ALREADY LOST. Google for memory fragmentation with various malloc implementations in multi-threaded applications. Thinking that you can just allocate in 2MB chunks is so _fundamnetally_ broken that this whole thread should have been laughed out of the room. Instead, you guys egg each other on. Stop the f*cking circle-jerk already. Linus -- 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