Re: [PATCH] perf: map pages in advance

[David Hildenbrand <david@redhat.com>]

On 29.11.24 13:48, Lorenzo Stoakes wrote:
> Will reply inline also but to be clear - we should differentiate between
> ongoing discussion about how best to tackle these things going forward
> vs. whether _this patch_ is OK :)
> 
> I don't think you're objecting to the patch as such, just disappointed
> about VM_PFNMAP and wanting to discuss this more generally?

Well, a bit of both :)

> 
> As I say below, we can't use VM_MIXEDMAP as it's broken for our case (we
> have to use page->mapping if there's a struct page), so I think _right now_
> this is the only sane solution.

I'm not so sure ...

I've also been wondering whether this particular user really wants to 
allocate and work on folios for the time being :/


Putting aside the remainder of what we discuss further below for now, 
I've just been wondering if we could somehow have two mappings with two 
separate ops. The one for the single R/W page, the other for the R/O 
pages ...

... but I'm not sure yet if that would completely help.

... still trying to grasp all the details here, and how to keep GUP working.

-- 
Cheers,

David / dhildenb