Re: [PATCH]time: Optimize nohz idle enter

From: Gaurav Jindal (Gaurav Jindal)
Date: Tue Jul 19 2016 - 06:01:32 EST


On Tue, Jul 19, 2016 at 10:47:37AM +0200, Thomas Gleixner wrote:
> On Thu, 14 Jul 2016, Gaurav Jindal (Gaurav Jindal) wrote:
> >
> > tick_nohz_start_idle is called before checking the condition if the idle tick
> > can be stopped. In case when can_stop_idle_tick returns 0, the function called
> > is of no use thus a extra call doing nothing.
> >
> > Shifting calling of function tick_nohz_start_idle inside the if condition makes
> > sure that corresponding operations are done only if idle tick can be actually
> > stopped. Observance for 1 minute on arm64 architecture shows that shifting code
> > can prevent 1.5% of extra calls thus optimizing the idle call sequence.
>
> Nice.
>
> > Signed-off-by: gaurav jindal<gaurav.jindal@xxxxxxxxxxxxxx>
> > Signed-off-by: sanjeev yadav<sanjeev.yadav@xxxxxxxxxxxxxx>
>
> This SOB chain is wrong. Sanjeev did not send the patch and is not the
> author. Please clarify.
>
Actually Sanjeev and me worked together, but since only one send the mail so I
included his name as SOB.
> Thanks,
>
> tglx

--
Regards
Gaurav Jindal
+91-8800803297