Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753948AbZFZGyc (ORCPT ); Fri, 26 Jun 2009 02:54:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750964AbZFZGyX (ORCPT ); Fri, 26 Jun 2009 02:54:23 -0400 Received: from one.firstfloor.org ([213.235.205.2]:43964 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750853AbZFZGyW (ORCPT ); Fri, 26 Jun 2009 02:54:22 -0400 Date: Fri, 26 Jun 2009 08:54:23 +0200 From: Andi Kleen To: Tejun Heo Cc: Andi Kleen , "H. Peter Anvin" , Andrew Morton , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, mingo@elte.hu, tglx@linutronix.de, cl@linux-foundation.org Subject: Re: [PATCHSET] percpu: generalize first chunk allocators and improve lpage NUMA support Message-ID: <20090626065423.GY6760@one.firstfloor.org> References: <1245850216-31653-1-git-send-email-tj@kernel.org> <20090624165508.30b88343.akpm@linux-foundation.org> <20090625000202.GR6760@one.firstfloor.org> <4A42C131.6040007@zytor.com> <20090625091939.GS6760@one.firstfloor.org> <4A43871F.9030507@zytor.com> <20090625195408.GW6760@one.firstfloor.org> <4A43DAFD.90409@zytor.com> <20090625202642.GX6760@one.firstfloor.org> <4A4418EA.9000705@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A4418EA.9000705@kernel.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 914 Lines: 25 On Fri, Jun 26, 2009 at 09:40:10AM +0900, Tejun Heo wrote: > Andi Kleen wrote: > >> I don't know why, but in the configuration I saw each percpu area was > >> something like 1.8 MB. > > > > That sounds like something that needs to be investigated and fixed then. > > In a sense per cpu space is precious like stack space and shouldn't > > be wasted. > > The large percpu space is most likely from lockdep. It would be better then to fix lockdep then to add weird hacks for that elsewhere. e.g. it could just allocate buffers in a cpu up/down callback and only put a pointer to these buffers into percpu. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/