Re: [LSF/MM/BPF TOPIC][RFC PATCH v4 00/27] Private Memory Nodes (w/ Compressed RAM)

[Gregory Price <gourry@gourry.net>]

On Wed, Feb 25, 2026 at 12:40:09PM +0000, Alejandro Lucero Palau wrote:
> 
> > /* This is my memory. There are many like it, but this one is mine. */
> > rc = add_private_memory_driver_managed(nid, start, size, name, flags,
> >                                         online_type, private_context);
> > 
> > page = alloc_pages_node(nid, __GFP_PRIVATE, 0);
> 
> 
> Hi Gregory,
> 
> 
> I can see the nid param is just a "preferred nid" with alloc pages. Using
> __GFP_PRIVATE will restrict the allocation to private nodes but I think the
> idea here is:
> 
> 
> 1) I own this node
> 
> 2) Do not give me memory from another private node but from mine.
> 
> 
> Should not this be ensure somehow?
> 

A right I set up GFP_PRIVATE for this

#define GFP_PRIVATE     (__GFP_PRIVATE | __GFP_THISNODE)

If your service hides the interface to get to this node behind something
it controls, and it doesn't enable things like reclaim/compaction etc,
then it's responsible for dealing with an out-of-memory situation.

__THISNODE was insufficient alone to allow isolation since it is used in
a variety of scenarios around the kernel.  v2 or v3 explored that.

~Gregory