Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269090AbUI3HD1 (ORCPT ); Thu, 30 Sep 2004 03:03:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269096AbUI3HD1 (ORCPT ); Thu, 30 Sep 2004 03:03:27 -0400 Received: from ozlabs.org ([203.10.76.45]:11212 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S269090AbUI3HDP (ORCPT ); Thu, 30 Sep 2004 03:03:15 -0400 Date: Thu, 30 Sep 2004 17:01:51 +1000 From: David Gibson To: Anton Blanchard Cc: Olaf Hering , Andrew Morton , Paul Mackerras , linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PPC64] Improved VSID allocation algorithm Message-ID: <20040930070151.GG21889@zax> Mail-Followup-To: David Gibson , Anton Blanchard , Olaf Hering , Andrew Morton , Paul Mackerras , linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org References: <20040913041119.GA5351@zax> <20040929194730.GA6292@suse.de> <20040930064037.GA3167@krispykreme.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040930064037.GA3167@krispykreme.ozlabs.ibm.com> User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1090 Lines: 25 On Thu, Sep 30, 2004 at 04:40:37PM +1000, Anton Blanchard wrote: > > > This patch went into 2.6.9-rc2-bk2, and my p640 does not boot anymore. > > Hangs after 'returning from prom_init', wants a power cycle. > > How much memory do you have? We might be filling up a hpte bucket > completely with certain amounts of memory. Bugger, bugger, bugger bugger. That's it. Just ran 4GB linear mapping with 4k pages through by hash scattering simulator - max bucket load is 2 with the old algo and 16 with the new one. Well, we just found the first case where the new algorithm scatters significantly worse than the old one. It would be something this dire, wouldn't it. -- David Gibson | For every complex problem there is a david AT gibson.dropbear.id.au | solution which is simple, neat and | wrong. http://www.ozlabs.org/people/dgibson - 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/