Messages in this thread | | | Date | Mon, 24 Mar 2014 11:00:32 +0100 | From | Lukasz Majewski <> | Subject | Re: [RFC v3 0/5] cpufreq:LAB: Support for LAB governor. |
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Hi Viresh,
> On 4 March 2014 15:57, Lukasz Majewski <l.majewski@samsung.com> wrote: > > Despite this patch set is working and applicable on top of 3.14-rc5, > > please regard it solely as a pure RFC. > > Okay, I am trying to do a review here and because you have mentioned > how different it is from the earlier versions, I am trying with a > fresh mind. i.e. with zero memories of earlier discussions :) > > LAB was: Legacy Application Boost ??
Yes, correct.
> > Probably mention that in your new threads as well, so that new readers > know the details. Also, like other governors, just name it "boost" > governor.
I think, that "LAB" name is with us for some time, so it would be a pity to discard it.
> > > This patch provides support for LAB governor build on top of > > ondemand. Previous version of LAB can be found here: > > http://thread.gmane.org/gmane.linux.kernel/1484746/match=cpufreq > > > > LAB short reminder: > > > > LAB uses information about how many cores are in "idle" state (the > > core idleness is represented as the value between 0 and 100) and > > the overall load of the system (from 0 to 100) to decide about > > frequency to be set. It is extremely useful with SoCs like > > Exynos4412, which can set only one frequency for all cores. > > Probably a description of how exactly these two values come into play > would have been more interesting here for all. Always think of new > followers of your patchset and so add all interesting things about it > when you resend it. > > If I remember well the logic was more or less like this: > - More idle cores means run few running cores at high frequency > - Less idle cores means don't run them at very high frequencies > > Right?
This is correct. Also, the underlying SoC - Exynos4412 has 4 cores with option to set frequency only on all of them.
> > What about making it as simple as: > - changing the ondemand governor only instead of adding a new governor
My goal is to not touch the ondemand code. It has matured, so I would like to leave it as it is.
> - Keeping the bahavior as is for all platforms not publishing boost > frequencies
This is also done - you get the LAB configuration specified in the DT for the particular platform/board.
> - If more cores are idle, enable switching to boost frequencies and > take them into consideration all the time.
I'm not sure if I have understood you, but something like that is also performed in the code.
> - If less cores are idle, disable boost frequencies..
As written above.
> > Lets discuss this first and then I will get into the very details of > your implementation.
Discussion about above functionalities requires consulting the implementation to be sure that our opinions are the same.
-- Best regards,
Lukasz Majewski
Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
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