From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932474AbWDMW14 (ORCPT ); Thu, 13 Apr 2006 18:27:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932475AbWDMW14 (ORCPT ); Thu, 13 Apr 2006 18:27:56 -0400 Received: from lixom.net ([66.141.50.11]:60325 "EHLO mail.lixom.net") by vger.kernel.org with ESMTP id S932474AbWDMW1z (ORCPT ); Thu, 13 Apr 2006 18:27:55 -0400 Date: Thu, 13 Apr 2006 17:27:21 -0500 To: Benjamin Herrenschmidt Cc: Muli Ben-Yehuda , paulus@samba.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [2/2] POWERPC: Lower threshold for DART enablement to 1GB, V2 Message-ID: <20060413222721.GN24769@pb15.lixom.net> References: <20060413020559.GC24769@pb15.lixom.net> <20060413022809.GD24769@pb15.lixom.net> <20060413025233.GE24769@pb15.lixom.net> <20060413064027.GH10412@granada.merseine.nu> <1144925149.4935.14.camel@localhost.localdomain> <20060413160712.GG24769@pb15.lixom.net> <1144961515.4935.22.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1144961515.4935.22.camel@localhost.localdomain> User-Agent: Mutt/1.5.11 From: Olof Johansson Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 14, 2006 at 06:51:55AM +1000, Benjamin Herrenschmidt wrote: > an improvement with the DART thanks to virtual merging. Currently, we > pay a cost due to our stupid invalidate mecanism that we should really > fix by shooting the TLB directly. What was keeping me from implementing this before was the lack of public documentation on how to do it. Has that changed? I'd be happy to do the implementation. > Also have you made sure all your > additions for handling crappy hardware are nicely wrapped in unlikely() > statements ? :) I would expect the dynamic predictor to work quite well on this. I'm not worried about the overhead of the tests as much as the overhead of having to enable the DART for smaller configs. If benchmark profiling shows different down the road then we can add them. -Olof