Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756741Ab3E0HfH (ORCPT ); Mon, 27 May 2013 03:35:07 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:34519 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756654Ab3E0HfE (ORCPT ); Mon, 27 May 2013 03:35:04 -0400 X-AuditID: cbfee61b-b7f8e6d00000524c-ad-51a30ca6058a Date: Mon, 27 May 2013 09:34:55 +0200 From: Lukasz Majewski To: Viresh Kumar Cc: Jonghwa Lee , "Rafael J. Wysocky" , linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, Vicent Guittot , Daniel Lezcano , MyungJoo Ham , Lukasz Majewski Subject: Re: [RFC v2 0/3][TESTS] LAB: Support for Legacy Application Booster governor - tests results Message-id: <20130527093455.04de38b1@amdc308.digital.local> In-reply-to: References: <1367590072-10496-1-git-send-email-jonghwa3.lee@samsung.com> <20130522122700.104ca5cd@amdc308.digital.local> <20130522164453.29cd3a7d@amdc308.digital.local> <20130524075640.0a5b80ff@amdc308.digital.local> <20130524103007.7bb206ee@amdc308.digital.local> <20130524132036.7e7d5ffe@amdc308.digital.local> Organization: SPRC Poland X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) MIME-version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrKLMWRmVeSWpSXmKPExsVy+t9jAd1lPIsDDc7dErd42vSD3WLeZ1mL zrNPmC3ePOK2uLxrDpvF594jjBa3G1ewWfQv7GWy6Djyjdli41cPBy6PO9f2sHmsm/aW2aNv yypGj0eLWxg9Pm+SC2CN4rJJSc3JLEst0rdL4Mr4Pu0ZS8EnkYqP+xczNTAeF+hi5OSQEDCR eL/6GhOELSZx4d56ti5GLg4hgUWMEov+P2aHcNqZJGZMW8ECUsUioCrx/8ZsNhCbTUBP4vPd p0DdHBwiAloSL2+mgtQzC1xgkjh1aRbYVGGBdIl/27rAbF4Ba4klk76D9XIKBEv07P/OBLFg KavEu9vfwIr4BSQl2v/9YIY4yU7i3KcN7BDNghI/Jt8DO4IZaNnmbU2sELa8xOY1b5knMArO QlI2C0nZLCRlCxiZVzGKphYkFxQnpeca6RUn5haX5qXrJefnbmIER8Yz6R2MqxosDjEKcDAq 8fAumLEoUIg1say4MvcQowQHs5IIb0I0UIg3JbGyKrUoP76oNCe1+BCjNAeLkjjvwVbrQCGB 9MSS1OzU1ILUIpgsEwenVAOj6KuYH5p+XF17tsrbFz6zjWsoKOIVvsucJrkt4+0CviL56V5T Vs040HXo6MUErsh9h52lZY141gk/27t/24zINarL7P2vvlJ8837BH46jlg+t0yYmSYlO+3KQ xVE1Ir3ykW/l5ktNb9fy/0mb/DLBitXu33ZHtwaO9xxXrr5ZKzN/3dv+mY0flFiKMxINtZiL ihMBkrgj64gCAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2842 Lines: 82 Hi Viresh, > On 24 May 2013 16:50, Lukasz Majewski wrote: > >> On 24 May 2013 14:00, Lukasz Majewski > >> wrote: > > > This is not safe IMHO to add permanently overclocked frequency to > > the freq table. Since, for example, thermal framework also asks for > > reference to this table. > > Yes, its wrong. Even adding it permanently this way would be a problem > if governor is changed to performance. :) > > > The idea beneath overclocking is to add "dangerous" frequency to the > > frequency table only when necessary (and remove it when not needed). > > Hmm.. probably the idea beneath is to use dangerous frequency only > when we are assured that we will not break system.. Exactly, this is the idea. > It doesn't have > anything to do with cpufreq table entries :) > > > In this way, the thermal framework (as it is done at our platform) > > will decrease the frequency (according to thermal governor :-) ) to > > safe level. > > > > Overclocking is disabled in 2 ways (at our setup): > > - thermal framework is here to help us > > - lab governor disables the overclocking when favorable conditions > > are gone. > > I don't want to discuss OR think about LAB for now.. Want to get > overclocking feature in first. > > > One more remark - enabling tb_en_over_clk at sysfs (echo 1 > >> /sys/devices/system/cpu/cpu0/cpufreq/tb_en_over_clk) > > adds overclock frequency to frequency table and updates policy. > > What if it is enabled and governor is changed to performance > without disabling it... Who will take care of disabling dangerous > frequencies? So we could disable overclocking by default when policy is changed, or when we remove governor (at cpufreq_unregister_governor()). > > One thing I am certain about is to make overclocking a generic and > core feature, rather than platform specific... Ok, I see your point. I will prepare appropriate patches to rewrite overclocking as a generic framework. > > What about adding overdrive frequencies in freq table permanently > but with .index field as: CPUFREQ_ENTRY_OVERDRIVE ?? > > This way we will use frequencies marked with > CPUFREQ_ENTRY_OVERDRIVE only when we have overclocking > enabled. And not at other times? It seems to be a good idea. In this way we could solve some other problems as well (like specifying not single overclocked frequency, make sysfs entries read only). As I've stated above, I will prepare only overclocking patches, with new generic approach. -- Best regards, Lukasz Majewski Samsung R&D Poland (SRPOL) | Linux Platform Group -- 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/