Re: [Resend LSF/MM/BPF TOPIC] A case of a CXL compressed memory tier

[Adam Manzanares <a.manzanares@samsung.com>]

On Tue, May 14, 2024 at 01:43:29PM +0200, Yiannis Nikolakopoulos wrote:
> Hello all,
> 
> This is almost literally last minute and the work itself is only
> getting started. But since I'm virtually attending, I thought to give
> it a shot in case it is of interest.
> 
> Background: at ZeroPoint Technologies we are developing inline memory
> compression IP. Currently we are focusing on CXL type 3 devices
> (memory expanders), effectively introducing a compressed memory tier
> (i.e. fulfilling the OCP specification "Hyperscale CXL Tiered Memory
> Expander Specification”).
> 
> To utilize the memory saved due to compression, we oversubscribe the
> Device Physical Address Space (DPA) in addition to some custom .io
> interfaces. If there is interest, I would be glad to present these
> APIs and how the host's point of view changes compared to a "typical"
> memory tiering system. The goal would be to get some early feedback
> and direction for our upstream driver development, before we start
> pushing the first RFCs.

I am interested in understanding the interfaces and how the memory will be
consumed and presented by the MM subsystem. It is my understanding that
we have a 30 min slot for CXL related topics open this morning. I think this 
would be a good fit.

> 
> Best regards,
> Yiannis Nikolakopoulos