Re: [PATCH 2/7] mm: shrinker: Add a .to_text() method for shrinkers

[Kent Overstreet <kent.overstreet@linux.dev>]

On Tue, Nov 28, 2023 at 11:27:11AM +0800, Muchun Song wrote:
> 
> 
> > On Nov 25, 2023, at 08:30, Kent Overstreet <kent.overstreet@linux.dev> wrote:
> > 
> > On Fri, Nov 24, 2023 at 11:08:11AM +0800, Qi Zheng wrote:
> >> Hi Kent,
> >> 
> >> On 2023/11/24 05:24, Kent Overstreet wrote:
> >>> On Thu, Nov 23, 2023 at 11:32:59AM +0800, Qi Zheng wrote:
> >>>>> + void (*to_text)(struct seq_buf *, struct shrinker *);
> >>>> 
> >>>> The "to_text" looks a little strange, how about naming it
> >>>> "stat_objects"?
> >>> 
> >>> The convention I've been using heavily in bcachefs is
> >>> typename_to_text(), or type.to_text(), for debug reports. The
> >> 
> >> OK.
> >> 
> >>> consistency is nice.
> >> 
> >> However, this is inconsistent with the name style of other
> >> shrinker callbacks. Please use the "objects" suffix. As for
> >> bcachefs's own callback function, you can use typename_to_text()
> >> to ensure consistency.
> > 
> > That would be inconsistent with introducing a convention to the wider
> > kernel.
> > 
> 
> I don not think .to_text is a good name. I really do not know what it means
> when I first look at this name. I knew you want to report the objects of
> shrinks, so why not use .report_objects or stat_objects proposed by Qi.
> Although .to_text is only used by bcachefs now, shrinker is a general module
> which is not only serving the bcachefs itself. I think it should be better
> to use a more straightforward name.

No, .report_objects or .stat_objects would be wrong; this isn't
generating a report on the objects owned by the shrinker, it's just a
report on the statistics of the shrinker itself.

That's why the convention is typename_to_text() - generate a text
representation of an object of that type.