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SubjectRe: [PATCH 4/9] mm, swap: tidy up swap device and cluster info helpers
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On 22.08.25 21:20, Kairui Song wrote:
> From: Kairui Song <kasong@tencent.com>
>
> swp_swap_info is the most commonly used helper for retrieving swap info.
> It has an internal check that may lead to a NULL return value, but
> almost none of its caller checks the return value, making the internal
> check pointless. In fact, most of these callers already ensured the
> entry is valid and never expect a NULL value.
>
> Tidy this up and shorten the name.

Shorter != better. But yes, "swp_swap" was a mess.

> If the caller can make sure the
> swap entry/type is valid and the device is pinned, use the new introduced
> swp_info/swp_type_info instead. They have more debug sanity checks and
> lower overhead as they are inlined.
>
> Callers that may expect a NULL value should use
> swp_get_info/swp_type_get_info instead.

High-level comments:

1) I hate the "swp" vs. "swap". Is that a valuable distinction or could
we just convert it to "swap" as we touch it?

You're converting swap_type_to_swap_info() to swp_type_to_swap_info(),
and I am not sure if that is the right direction :)


2) Can we just call it "swap_entry" when we work on a swap entry and
"swap_type" when we work on a swap type in the function name?

swp_info() is a rather bad function name.


3) I am not sure about "to" -> "get". "to" is much more readable in that
context and consistent.


4) swp_info[] vs. swap_info() gah.


I would just have done:

swap_type_to_info(int type)
__swap_type_to_info(int type)
swap_entry_to_info(swp_entry_t entry)
__swap_entry_to_info(swp_entry_t entry)

__ are the expert functions where we don't expect NULL.

--
Cheers

David / dhildenb


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