Re: [PATCH UPDATED] percpu: use dynamic percpu allocator as the default percpu allocator

Ingo Molnar
2009-04-02T03:27:44Z

* Christoph Lameter <cl@linux.com> wrote:

> > A sub-sub argument was that perhaps we should not split .data
> > and .bss variables into separate sections - it doubles the
> > chance of false cacheline sharing and spreads the cacheline
> > footprint.
>
> False cacheline sharing is something normal that comes with the
> cpu caching schemes. As long as there is no significant impact on
> performance we are fine with it. Extensive measures to avoid false
> cacheline sharing on unimportant variables increases the cache
> footprint of code.

You didnt really answer to my suggestion(s) though. You only stated
that:

"problem XYZ is something normal that comes with the cpu caching
schemes. As long as there is no significant impact on
performance weare fine with it."

Which i'd proffer is true for any given value of XYZ ;-)

Ingo