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    SubjectRe: nohz problem with idle time on old hardware
    On Wed, 13 Nov 2013, Steven Rostedt wrote:

    > On Wed, 13 Nov 2013 10:31:34 -0500
    > Steven Rostedt <rostedt@goodmis.org> wrote:
    >
    > > The trace does indeed show that a tick is happening, as the config has
    > > HZ=250 (4ms) and we see a tick happen every 4ms. But for some reason,
    > > we don't update the the idle time correctly when nohz is enabled.
    > >
    > > When I say nohz is enabled, I mean that we don't have nohz=off in the
    > > command line. There seems to be some difference between having nohz=off
    > > and having nohz disabled at runtime.
    >
    >
    > Looking at the differences between nohz=off from the command line, and
    > disabled at run time seems to be the variable "tick_nohz_enabled". I
    > don't see where it gets set to zero except for nohz=off.

    Right. It's telling you if NOHZ is enabled. It's not telling you that
    NOHZ is active.

    Thanks,

    tglx


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