Re: [LSF/MM/BPF TOPIC] State Of The Page

["Christoph Lameter (Ampere)" <cl@linux.com>]

On Sun, 21 Jan 2024, Matthew Wilcox wrote:

>
> I'd like to keep this topic relevant to as many people as possible.
> I can add a proposal for a topic on both the PCP and Buddy allocators
> (I have a series of Thoughts on how the PCP allocator works in a memdesc
> world that I haven't written down & sent out yet).

Well the PCP cache's  (I would not call it an allocator) intent is to 
provide cache hot / tlb hot pages. In some ways this is like the SLAB/SLUB 
situation. I.e. lists of objects vs. service objects that are 
locally related.

Can we come up with a design that uses a huge page (or some 
arbitrary page size) and the breaks out portions of the large page? That 
way potentially TLB use can be reduced (multiple sections of a large page 
use the same TLB) and defragmentation occurs because allocs and frees 
focus on a selection of large memory sections.

This is rougly equivalent to a per cpu page (folio?) in SLUB where cache 
hot objects can be served from a single memory section and also freed back 
without too much interaction with higher level more expensive components 
of the allocator.