On 17 June 2016 at 17:27, Thomas Gleixner [off-list ref] wrote:

On Fri, 17 Jun 2016, Zhaoyang Huang wrote:

quoted

There should be a gap between tick_nohz_idle_enter and
tick_nohz_get_sleep_length when idle, which will cause the
sleep_length is not very precised. Change it in this patch.

What kind of imprecision are we talking about? Seconds, nanoseconds or
lightyears?

Your changelog lacks any form of useful information.

Thanks,

        tglx

sorry for the confusion. The imprecision can be caused by, for
example, the callback function registered for CPU_PM_ENTER, which may
consume a period of time within the 'idle' time. Besides, I also
wonder why not calc the 'sleep_length' in the
tick_nohz_get_sleep_length?  This value is calculated at very
beginning of the idle in current approach.