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From: Marco Elver <elver@google.com>
Date: Wed, 3 Jan 2024 12:25:51 +0100
Message-ID: <CANpmjNPsBUJy6tkOdRSJyWrS9CMUOQhQyb7_hwmw68pjjiEDWQ@mail.gmail.com>
Subject: Re: [PATCH] list: Add hlist_count_nodes()
To: Pierre Gondois <pierre.gondois@arm.com>
Cc: linux-kernel@vger.kernel.org, Kees Cook <keescook@chromium.org>, 
	Lucas De Marchi <lucas.demarchi@intel.com>, Jani Nikula <jani.nikula@intel.com>, 
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Ingo Molnar <mingo@kernel.org>
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On Wed, 3 Jan 2024 at 10:02, Pierre Gondois <pierre.gondois@arm.com> 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@arm.com>

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.

> ---
>  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
>