Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753729AbZKGW7s (ORCPT ); Sat, 7 Nov 2009 17:59:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753489AbZKGW7q (ORCPT ); Sat, 7 Nov 2009 17:59:46 -0500 Received: from mga12.intel.com ([143.182.124.36]:42998 "EHLO azsmga102.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753460AbZKGW7p (ORCPT ); Sat, 7 Nov 2009 17:59:45 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,701,1249282800"; d="scan'208";a="208893758" Message-ID: <4AF5FBC7.9000105@linux.intel.com> Date: Sat, 07 Nov 2009 16:59:19 -0600 From: Arjan van de Ven User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: Thomas Renninger CC: "Luis R. Rodriguez" , davej@redhat.com, cpufreq@vger.kernel.org, linux-kernel@vger.kernel.org, mcgrof@gmail.com, Matthew Garrett , Reinette Chatre , Aeolus Yang , Amod Bodas , David Quan , Kishore Jotwani Subject: Re: [PATCH] cpu-freq: add troubleshooting section for FSB changes References: <1257537660-5301-1-git-send-email-lrodriguez@atheros.com> <200911072152.57596.trenn@suse.de> <4AF5F47C.5000402@linux.intel.com> <200911072347.05786.trenn@suse.de> In-Reply-To: <200911072347.05786.trenn@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 999 Lines: 18 >> in addition, most FSB systems have the memory controller in the chipset, >> next to the PCI logic... so that the FSB bus for DMA transactions only >> carries the snoop traffic, not the whole data. > So when should people look at this? at this point the atheros folks haven't even confirmed that this is the cause... I'm not saying that the linux behavior is optimal with P states (I have a rather sizeable algorithm rewrite in the queue) but to blame anything and everything on a half-speed FSB during a very idle system? I'm still somewhat skeptical. Again.. the CPU is basically idle here (otherwise ondemand would ramp the freq up quickly); at which point the FSB traffic mostly is just cache coherency traffic.... much less bandwidth intensive. -- 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/