Re: [RFC Patch 3/3] mm/slub: setup maxim per-node partial according to cpu numbers

Feng Tang
2023-09-15T05:15:03Z

On Thu, Sep 14, 2023 at 07:40:22PM -0700, Lameter, Christopher wrote:
> On Thu, 14 Sep 2023, Feng Tang wrote:
>
> > One reason I wanted to revisit the MIN_PARTIAL is, it was changed from
> > 2 to 5 in 2007 by Christoph, in commit 76be895001f2 ("SLUB: Improve
> > hackbench speed"), the system has been much huger since then.
> > Currently while a per-cpu partial can already have 5 or more slabs,
> > the limit for a node with possible 100+ CPU could be reconsidered.
>
> Well the trick that I keep using in large systems with lots of memory is to
> use huge page sized page allocation. The applications on those already are
> using the same page size. Doing so usually removes a lot of overhead and
> speeds up things significantly.
>
> Try booting with "slab_min_order=9"

Thanks for sharing the trick! I tried and it works here. But this is
kind of extreme and fit for some special use case, and these patches
try to be useful for generic usage.

Thanks,
Feng