Re: [PATCH 01/10] mm: page_ref_add_unless() does not trace 'u' argument

[Matthew Wilcox]

On Wed, Dec 08, 2021 at 08:35:35PM +0000, Pasha Tatashin wrote:
> In other page_ref_* functions all arguments and returns are traced, but
> in page_ref_add_unless the 'u' argument which stands for unless boolean
> is not traced. However, what is more confusing is that in the tracing
> routine:
> 	__page_ref_mod_unless(struct page *page, int v, int u);
> 
> The 'u' argument present, but instead a return value is passed into
> this argument.
> 
> Add a new template specific for page_ref_add_unless(), and trace all
> arguments and the return value.

The special casing of '1' for device pages is going away, so NAK
to this user-visible change.