[dm-devel] [PATCH] slab: introduce the flag SLAB_MINIMIZE_WASTE

[Christopher Lameter]

On Wed, 21 Mar 2018, Matthew Wilcox wrote:

> > Have a look at include/linux/mempool.h.
>
> That's not what mempool is for.  mempool is a cache of elements that were
> allocated from slab in the first place.  (OK, technically, you don't have
> to use slab as the allocator, but since there is no allocator that solves
> this problem, mempool doesn't solve the problem either!)

You can put the page allocator in there instead of a slab allocator.

> > But still the increased page order will get you into trouble with
> > fragmentation when the system runs for a long time. That is the reason we
> > try to limit the allocation sizes coming from the slab allocator.
>
> Right; he has a fallback already (vmalloc).  So ... let's just add the
> interface to allow slab caches to have their order tuned by users who
> really know what they're doing?

Ok thats trivial.