Re: [PATCH] nohz: make the idle_entrytime/idle_exittime correct

From: Thomas Gleixner
Date: Thu Sep 17 2015 - 17:46:15 EST


On Wed, 16 Sep 2015, Yunhong Jiang wrote:

> Currently the idle_entrytime is updated on idle_entry, idle_exit and
> get_cpu_idle/iowait_time_us() with non-NULL parameter. This makes the
> idle_entrytime not the real entrytime anymore. The idle_exittiime is
> updated when exit tickless state, which can be idle tickless or full
> tickless.

If something calls one of the functions then the cpu is not idle. It's
running code.

> Change the idle_entrytime to be updated only when enter idle, the
> idle_exittime to be updated only when exit idle. Update
> the get_cpu_idle_iowait_time_us() accordingly.

And the rationale for this change is?

Thanks,

tglx
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