From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: [PATCH] cpufreq: stats: Do not populate stats when policy->cur has no exact match Date: Mon, 18 Nov 2013 09:08:09 -0600 Message-ID: <528A2D59.3080001@ti.com> References: <1384561243-30391-1-git-send-email-nm@ti.com> <1423628.uM8DtnYzDe@vostro.rjw.lan> <5287010F.9000508@linaro.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5287010F.9000508@linaro.org> Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: viresh kumar , "Rafael J. Wysocki" Cc: cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, ceh@ti.com, Tobias Diedrich , Konrad Rzeszutek Wilk , Dave Jones On 11/15/2013 11:22 PM, viresh kumar wrote: > On Saturday 16 November 2013 06:40 AM, Rafael J. Wysocki wrote: >> On Friday, November 15, 2013 06:20:43 PM Nishanth Menon wrote: > >>> So, instead of having a statistics information that never ever >>> reflects valid data in the mentioned case and scratching our heads, we >>> instead, refuse to populate any of the statistics entries and note in >>> kernel log the error condition for developers to fix. The only useable > > s/useable/usable > >>> information are the available frequencies which is already available >>> in other cpufreq sysfs entries. > >> I like this one. Any objections from anyone? > > Well nothing against the patch but I have other thoughts. There are platforms > which might have no choice of fixing this issue as their bootloaders might be > setting boot freq to any value outside of our freq table. > > And those might not have a chance to fix that in driver as well in case they are > using something like cpufreq-cpu0.. > > So, eventually this patch wouldn't do anything except giving a boot time error > and not initializing any stats at all.. > > Wouldn't it be better to create another frequency in all these tables, which > will be an *Invalid* frequency.. With a value of -1 (i.e. largest value of an > unsigned int) ?? > > And so nobody will ever miss stats again, even if they are running on invalid > frequencies. We will capture that information too: > - we have moved from/to invalid frequency to/from a valid/invalid frequency this > much times. > - We have stayed at valid/invalid frequencies for this much time. > > I have a untested patch for this. If this looks okay, Nishant can you please try > below patch? With some fixups from your side :) http://pastebin.mozilla.org/3628975 I agree that it does show something, but would we not rather prefer to stick with the entries available in freq_table than have to deal with invalid frequencies that may be provided by the driver? for example: how do we in stat know that there will only be one invalid frequency request? > [..] > (@Rafael: Finally I have moved to thunderbird, found a way out, so no more > crappy attachments from me :)) > there are some patch wrapping that thunderbird tends to do - I prefer mutt that way, when I need to send inline patches :). -- Regards, Nishanth Menon