Re: [RFC 2/2] Introduce sysctl(s) for the migration costs

[Mike Galbraith]

On Fri, 2018-02-09 at 12:33 -0500, Steven Sistare wrote:
> On 2/9/2018 12:08 PM, Mike Galbraith wrote:
> 
> > Shrug.  It's bogus no mater what we do.  Once Upon A Time, a cost
> > number was generated via measurement, but the end result was just as
> > bogus as a number pulled out of the ether.  How much bandwidth you have
> > when blasting data to/from wherever says nothing about misses you avoid
> > vs those you generate.
> 
> Yes, yes and yes. I cannot make the original tunable less bogus.  Using a smaller
> cost for closer caches still makes logical sense and is supported by the data.

You forgot to write "microscopic" before "data" :)  I'm mostly agnostic
about this, but don't like the yet more knobs that 99.99% won't touch.

	-Mike