Re: [PATCH] list: Add hlist_count_nodes()

[Pierre Gondois]

Hello Marco,

On 1/3/24 12:25, Marco Elver wrote:
> On Wed, 3 Jan 2024 at 10:02, Pierre Gondois <pierre.gondois@xxxxxxx> wrote:
> > Add a function to count nodes in a hlist. hlist_count_nodes()
> > is similar to list_count_nodes().
> >
> > Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
>
> Is this patch part of another patch series? As-is, this will be dead
> code, and there's no guarantee someone will just go and delete it in
> future. Although this function looks useful, we also should avoid
> adding new dead code.

The function is indeed not used in the project right now. I needed
it for a private module. If it helps integrating the function and
not make it dead code, maybe I could add usages at the following
places:
- drivers/gpu/drm/drm_hashtab.c::print_binder_node_nilocked()
- drivers/md/bcache/sysfs.c::bch_cache_max_chain()

Regards,
Pierre

> > ---
> >   include/linux/list.h | 15 +++++++++++++++
> >   1 file changed, 15 insertions(+)
> >
> > diff --git a/include/linux/list.h b/include/linux/list.h
> > index 1837caedf723..0f1b1d4a2e2e 100644
> > --- a/include/linux/list.h
> > +++ b/include/linux/list.h
> > @@ -1175,4 +1175,19 @@ static inline void hlist_move_list(struct hlist_head *old,
> >               pos && ({ n = pos->member.next; 1; });                     \
> >               pos = hlist_entry_safe(n, typeof(*pos), member))
> >
> > +/**
> > + * hlist_count_nodes - count nodes in the hlist
> > + * @head:      the head for your hlist.
> > + */
> > +static inline size_t hlist_count_nodes(struct hlist_head *head)
> > +{
> > +       struct hlist_node *pos;
> > +       size_t count = 0;
> > +
> > +       hlist_for_each(pos, head)
> > +               count++;
> > +
> > +       return count;
> > +}
> > +
> >   #endif
> > --
> > 2.25.1