From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Renninger Subject: Re: ondemand governor and passive cooling broken? Date: Thu, 25 Aug 2005 12:30:03 +0200 Message-ID: <430D9DAB.6050502@renninger.de> References: <88056F38E9E48644A0F562A38C64FB600588ED10@scsmsx403.amr.corp.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <88056F38E9E48644A0F562A38C64FB600588ED10@scsmsx403.amr.corp.intel.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cpufreq-bounces@lists.linux.org.uk Errors-To: cpufreq-bounces+glkc-cpufreq=m.gmane.org@lists.linux.org.uk Content-Type: text/plain; charset="us-ascii" To: "Pallipadi, Venkatesh" Cc: cpufreq@lists.linux.org.uk, Dominik Brodowski Pallipadi, Venkatesh wrote: > > >>-----Original Message----- >>From: Thomas Renninger [mailto:mail@renninger.de] >>Sent: Saturday, August 20, 2005 9:49 PM >>To: Dominik Brodowski >>Cc: cpufreq@lists.linux.org.uk; Pallipadi, Venkatesh >>Subject: Re: ondemand governor and passive cooling broken? >> >>Hi, >> >>This makes ondemand governor aware of thermal limits. >>The policy was buffered and new policy values never reached >>the governor. > > I don't think there is an issue with buffering here. > This_dbs_info->cur_policy is a pointer to the cpufreq policy (and not > allocated by ondemand governor). So, any change to max/min in cpufreq > should be automatically getting reflected. Atleast that was the intent > with having policy pointer. If it is not happening then that should be a > bug. I don't think that this memcpy is required here. > You are right. I tried to reproduce this problem with a powernow-k8 machine and thermal cooling worked just fine. >>I just used the cpufreq_get_policy call every time the load is checked, >>maybe the new policy should be made available via notifier as >>it is done >>for the cur_freq in the userspace governor? >>If this sounds reasonable I can come up with a bigger patch on Monday. >> >>However, thermal cooling still does not always work right: >> >> - Sometimes the limit is not decreased correctly in polling >>frequency time >> (I saw it at max for more than 20 secs, polling freq 5 >>secs, passive tp exceeded). >> Strange enough, that seems to happen only in rare cases. >> - I also saw the limit stuck at lowest frequency even after >>getting back in >> normal temperature zones. > > I think we need to do some more things to intergrate cpufreq and thermal > cooling. Especially in relation to polling frequency. Probably, ondemand > governor should slow down its polling interval to something higher than > thermal polling frequency as soon as it notices the passive cooling is > on. Don't know. I will try to get a speedstep-centrino machine and have a look whether this makes a difference and also play around a bit with thermal polling freq and ondemand configs. Do you think this could be a driver specific problem? Thanks, Thomas