Re: [PATCH 03/16] mm: add vma_desc_size(), vma_desc_pages() helpers

Jason Gunthorpe
2025-09-08T15:57:00Z

On Mon, Sep 08, 2025 at 05:50:18PM +0200, David Hildenbrand wrote:

> So in practice there is indeed not a big difference between a private and
> cow mapping.

Right and most drivers just check SHARED.

But if we are being documentative why they check shared is because the
driver cannot tolerate COW.

I think if someone is cargo culting a diver and sees
'vma_never_cowable' they will have a better understanding of the
driver side issues.

Driver's don't actually care about private vs shared, except this
indirectly implies something about cow.

Jason