Re: [NOHZ] Remove scheduler_tick_max_deferment

From: Paul E. McKenney
Date: Mon Nov 10 2014 - 11:01:13 EST


On Mon, Nov 10, 2014 at 12:41:38PM +0530, Viresh Kumar wrote:
> On 6 November 2014 22:54, Christoph Lameter <cl@xxxxxxxxx> wrote:
>
> > We did not need to housekeeper in the dynticks idle case. What is so
> > different about dynticks busy?
>
> We do have a running task here and so the stats are important..
>
> > I may not have the complete picture of the timer tick processing in my
> > mind these days (it has been a lots of years since I did any work there
> > after all) but as far as my arguably simplistic reading of the code goes I
> > do not see why a housekeeper would be needed there. The load is constant
> > and known in the dynticks busy case as it is in the dynticks idle case.
>
> I tried to initiate a thread on similar stuff, might be helpful:
>
> https://lkml.org/lkml/2014/5/22/131

Would it make sense for unlimited max deferment to be available as
a boot parameter? That would allow people who want tick-free execution
more than accurate stats to get that easily, while keeping stats accurate
for everyone else.

Thanx, Paul

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