From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 14 Jan 2008 09:14:18 +0100 From: Ingo Molnar Subject: Re: [PATCH 00/10] x86: Reduce memory and intra-node effects with large count NR_CPUs Message-ID: <20080114081418.GB18296@elte.hu> References: <20080113183453.973425000@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080113183453.973425000@sgi.com> Sender: owner-linux-mm@kvack.org Return-Path: To: travis@sgi.com Cc: Andrew Morton , Andi Kleen , Christoph Lameter , Jack Steiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: * travis@sgi.com wrote: > This patchset addresses the kernel bloat that occurs when NR_CPUS is > increased. The memory numbers below are with NR_CPUS = 1024 which I've > been testing (4 and 32 real processors, the rest "possible" using the > additional_cpus start option.) These changes are all specific to the > x86 architecture, non-arch specific changes will follow. thanks, i'll try this patchset in x86.git. > 32cpus 1kcpus-before 1kcpus-after > 7172678 Total +23314404 Total -147590 Total 1kcpus-after means it's +23314404-147590, i.e. +23166814? (i.e. a 0.6% reduction of the bloat?) i.e. we've got ~22K bloat per CPU - which is not bad, but because it's a static component, it hurts smaller boxes. For distributors to enable CONFIG_NR_CPU=1024 by default i guess that bloat has to drop below 1-2K per CPU :-/ [that would still mean 1-2MB total bloat but that's much more acceptable than 23MB] Ingo -- 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