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    SubjectRE: [RFC/RFT][PATCH v3 0/6] sched/cpuidle: Idle loop rework
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    On 2018.03.11 08:52 Doug Smythies wrote:
    > On 2018.03.11 03:22 Rafael J. Wysocki wrote:
    >> On Sunday, March 11, 2018 8:43:02 AM CET Doug Smythies wrote:
    >>> On 2018.03.10 15:55 Rafael J. Wysocki wrote:
    >>>> On Saturday, March 10, 2018 5:07:36 PM CET Doug Smythies wrote:
    >>>>> On 2018.03.10 01:00 Rafael J. Wysocki wrote:
    >>>
    >>> ... [snip] ...
    >>>
    >>>> The information that they often spend more time than a tick
    >>>> period in state 0 in one go *is* relevant, though.
    >>>>
    >>>>
    >>>> That issue can be dealt with in a couple of ways and the patch below is a
    >>>> rather straightforward attempt to do that. The idea, basically, is to discard
    >>>> the result of governor prediction if the tick has been stopped alread and
    >>>> the predicted idle duration is within the tick range.
    >>>
    >>>> Please try it on top of the v3 and tell me if you see an improvement.
    >>>
    >>> It seems pretty good so far.
    >>> See a new line added to the previous graph, "rjwv3plus".
    >>>
    >>> http://fast.smythies.com/rjwv3plus_100.png
    >>
    >> OK, cool!
    >>
    >> Below is a respin of the last patch which also prevents shallow states from
    >> being chosen due to interactivity_req when the tick is stopped.
    >>
    >> You may also add a poll_idle() fix I've just posted:
    >>
    >> https://patchwork.kernel.org/patch/10274595/
    >>
    >> on top of this. It makes quite a bit of a difference for me. :-)
    >
    > I will add and test, but I already know from testing previous versions
    > of this patch, from Rik van Riel and myself, that the results will be
    > awesome.

    And the results are indeed awesome.

    A four hour 100% load on one CPU test was run, with trace, however
    there is nothing to report, as everything is great.

    The same graph as the last couple of days, with a new line added for
    V3 + the respin of patch 7 of 6 + the poll-idle fix, called rjwv3pp,
    is here:

    http://fast.smythies.com/rjwv3pp_100.png

    ... Doug


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