Re: [RFC PATCH 0/4] Add fbind() and NUMA mempolicy support for KVM guest_memfd

Matthew Wilcox
2024-11-07T15:10:14Z

On Thu, Nov 07, 2024 at 02:24:20PM +0530, Shivank Garg wrote:
> The folio allocation path from guest_memfd typically looks like this...
>
> kvm_gmem_get_folio
> filemap_grab_folio
> __filemap_get_folio
> filemap_alloc_folio
> __folio_alloc_node_noprof
> -> goes to the buddy allocator
>
> Hence, I am trying to have a version of filemap_alloc_folio() that takes an mpol.

It only takes that path if cpuset_do_page_mem_spread() is true. Is the
real problem that you're trying to solve that cpusets are being used
incorrectly?

Backing up, it seems like you want to make a change to the page cache,
you've had a long discussion with people who aren't the page cache
maintainer, and you all understand the pros and cons of everything,
and here you are dumping a solution on me without talking to me, even
though I was at Plumbers, you didn't find me to tell me I needed to go
to your talk.

So you haven't explained a damned thing to me, and I'm annoyed at you.
Do better. Starting with your cover letter.