Re: [PATCH v3 05/12] mm, swap: unify large folio allocation

[David Hildenbrand (Arm)]

On 5/11/26 16:37, Kairui Song wrote:
> On Mon, May 11, 2026 at 8:58 PM David Hildenbrand (Arm)
> <david@xxxxxxxxxx> wrote:
>>
>> On 4/21/26 08:16, Kairui Song via B4 Relay wrote:
>>> From: Kairui Song <kasong@xxxxxxxxxxx>
>>>
>>> Now that direct large order allocation is supported in the swap cache,
>>> both anon and shmem can use it instead of implementing their own methods.
>>> This unifies the fallback and swap cache check, which also reduces the
>>> TOCTOU race window of swap cache state: previously, high order swapin
>>> required checking swap cache states first, then allocating and falling
>>> back separately. Now all these steps happen in the same compact loop.
>>>
>>> Order fallback and statistics are also unified, callers just need to
>>> check and pass the acceptable order bitmask.
>>>
>>> There is basically no behavior change. This only makes things more
>>> unified and prepares for later commits. Cgroup and zero map checks can
>>> also be moved into the compact loop, further reducing race windows and
>>> redundancy
>>>
>>
>> You should spell out the rename from swapin_folio() to swapin_entry() [and why
>> it is done].
>>
>> swapin_readahead() vs. swapin_entry() looks a bit odd, fiven that both consume
>> an entry.
> 
> Yes, the current status is a bit odd, about two years ago I also
> wanted to name it `swapin_direct()`.
> https://lore.kernel.org/linux-mm/20240326185032.72159-3-ryncsn@xxxxxxxxx/
> 
> But actually ZRAM or shmem would also benefit from supporting unified
> readahead like this:
> https://lore.kernel.org/linux-mm/20240102175338.62012-6-ryncsn@xxxxxxxxx/
> 
> So calling it `swapin_entry` seems more future-proof. At some point in
> the future we might remove `swapin_readahead`. All swapin operations
> could have a unified or at least a per-device readahead policy like
> the one in the link above, instead of the current policy where the
> caller must decide whether to perform readahead.
> 
> But any suggestion on naming is welcome :)

The other proposal

	https://lore.kernel.org/all/tencent_CD11FE9B4A0B362E95E776C5F679598FAA07@xxxxxx/

calls it

	swapin_synchronous_folio

Maybe just swapin_sync_io()/swapin_sync() or sth like that?


-- 
Cheers,

David