Re: [PATCH v7 1/3] mm: make persistent huge zero folio read-only

On Thu, Sep 3, 2026 at 10:09 PM Dave Hansen [off-list ref] wrote:

On 9/3/26 02:20, Mike Rapoport wrote:

quoted

On Wed, Sep 02, 2026 at 01:59:15PM -0700, Dave Hansen wrote:

quoted

On 9/1/26 08:18, Xueyuan Chen wrote:

quoted

+static inline int set_direct_map_ro(struct page *page, unsigned int nr)
+{
+   return 0;
+}

I still really think the stub here needs to return an error *or* the
thing needs to just be void and tell folks that they can't know whether
it worked or not.

All other stubs return 0 here when an arch does not support set_direct_map.
I'm for keeping them all consistent and fixing that technical debt as a
whole rather than creating a one-off here.

Oof. I didn't realize the set_direct_map_*() functions all did this.

I do think it's generally a bad idea, and I'm also OK if it is not fixed
up here.

OK, I'll leave it as-is then.

Thanks,
Xueyuan