Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Tue, 1 Oct 2019 11:31:32 +0200 | Subject | Re: [RFC/RFT][PATCH v8] cpuidle: New timer events oriented governor for tickless systems |
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On Sun, Sep 29, 2019 at 6:05 PM Doug Smythies <dsmythies@telus.net> wrote: > > On 2019.09.26 09:32 Doug Smythies wrote: > > > If the deepest idle state is disabled, the system > > can become somewhat unstable, with anywhere between no problem > > at all, to the occasional temporary jump using a lot more > > power for a few seconds, to a permanent jump using a lot more > > power continuously. I have been unable to isolate the exact > > test load conditions under which this will occur. However, > > temporarily disabling and then enabling other idle states > > seems to make for a somewhat repeatable test. It is important > > to note that the issue occurs with only ever disabling the deepest > > idle state, just not reliably. > > > > I want to know how you want to proceed before I do a bunch of > > regression testing. > > I did some regression testing anyhow, more to create and debug > a methodology than anything else. > > > On 2018.12.11 03:50 Rafael J. Wysocki wrote: > > > >> v7 -> v8: > >> * Apply the selection rules to the idle deepest state as well as to > >> the shallower ones (the deepest idle state was treated differently > >> before by mistake). > >> * Subtract 1/2 of the exit latency from the measured idle duration > >> in teo_update() (instead of subtracting the entire exit latency). > >> This makes the idle state selection be slightly more performance- > >> oriented. > > > > I have isolated the issue to a subset of the v7 to v8 changes, however > > it was not the exit latency changes. > > > > The partial revert to V7 changes I made were (on top of 5.3): > > The further testing showed a problem or two with my partial teo-v7 reversion > (I call it teo-v12) under slightly different testing conditions. > > I also have a 5.3 based kernel with the current teo reverted and the entire > teo-v7 put in its place. I have yet to find a idle state disabled related issue > with this kernel. > > I'll come back to this thread at a later date with better details and test results.
Thanks for this work!
Please also note that there is a teo patch in 5.4-rc1 that may make a difference in principle.
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