page pools, was Re: [PATCH v9 1/5] drm: Add a sharable drm page-pool implementation

[Christoph Hellwig]

On Wed, Jun 30, 2021 at 01:34:17AM +0000, John Stultz wrote:
> This adds a shrinker controlled page pool, extracted
> out of the ttm_pool logic, and abstracted out a bit
> so it can be used by other non-ttm drivers.

Can you explain in detail why you need a differnt page pool over the one
maintained by the page allocator?  Fragmenting the memory into all kinds
of pools has lots of downsides, so the upsides need to be explained in
detail.