Re: [NOHZ] Remove scheduler_tick_max_deferment

[Frederic Weisbecker]

On Tue, Nov 11, 2014 at 08:58:35AM -0600, Christoph Lameter wrote:
> On Mon, 10 Nov 2014, Frederic Weisbecker wrote:
> 
> > Ok, I confess we moved part of that housekeeping to the syscall/exception/interrupt
> > entry path. We did that for cputime accounting and RCU. And it's possible to
> > even do that for timekeeping. But then the kernel entrypoint is going to be extremely
> > costly. It's worth CPU 0 as a sacrificial lamb.
> 
> Well we can redirect to the scheduler setting the task flag and handle
> costly stuff there if necessary?

"there" here is the syscall/exception/interrupt entry path. And like I said, updating
timekeeping from these places is overkill (although we do it in interrupt entry on
dynticks-idle, but we don't have timekeeping when all system is idle).
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