Re: [PATCH v14 002/138] mm: Introduce struct folio

[Darrick J. Wong]

On Wed, Jul 21, 2021 at 04:42:36AM +0100, Matthew Wilcox wrote:
> On Tue, Jul 20, 2021 at 01:40:05PM +0300, Mike Rapoport wrote:
> > > +/**
> > > + * folio_shift - The number of bits covered by this folio.
> > 
> > For me this sounds like the size of the folio in bits.
> > Maybe just repeat "The base-2 logarithm of the size of this folio" here and
> > in return description?
> > 
> > > + * @folio: The folio.
> > > + *
> > > + * A folio contains a number of bytes which is a power-of-two in size.
> > > + * This function tells you which power-of-two the folio is.
> > > + *
> > > + * Context: The caller should have a reference on the folio to prevent
> > > + * it from being split.  It is not necessary for the folio to be locked.
> > > + * Return: The base-2 logarithm of the size of this folio.
> > > + */
> 
> I've gone with:
> 
>  /**
> - * folio_shift - The number of bits covered by this folio.
> + * folio_shift - The size of the memory described by this folio.
>   * @folio: The folio.
>   *
> - * A folio contains a number of bytes which is a power-of-two in size.
> - * This function tells you which power-of-two the folio is.
> + * A folio represents a number of bytes which is a power-of-two in size.
> + * This function tells you which power-of-two the folio is.  See also
> + * folio_size() and folio_order().
>   *
>   * Context: The caller should have a reference on the folio to prevent
>   * it from being split.  It is not necessary for the folio to be locked.
> 

I like it. :)

--D