Re: [PATCH v10 0/6] mm/swap, memcg: Introduce swap tiers for cgroup based swap control

[Yosry Ahmed]

On Sun, Jul 12, 2026 at 7:57 PM Youngjun Park <youngjun.park@xxxxxxx> wrote:
>
> This is the v10 series of the swap tier patchset.
>
> v10 folds in the Sashiko review fixes for the selftests added in v9 and
> rebases onto the current mm-new. There are no functional changes to the
> core swap or memcg code since v9; see the changelog for details.
>
> For context, the bulk of the series is unchanged since v8, with great thanks
> to Shakeel Butt and Yosry for the reviews and discussions [1] that shaped it.
> The main change in v8 was the interface change to use memory.swap.tiers.max
> with '0' (disable) and 'max' (enable) values. This mechanism was suggested
> by Shakeel and Yosry.
>
> This change allows for future extensions to control swap between tiers and
> aligns better with existing memcg interfaces. It is confined to patch #3's
> user-facing interface; internally, patch #3 still uses the existing mask
> processing method, which is implementation-efficient.
>
> We also discussed tier extensions. Thanks to Yosry, Nhat and Shakeel for their
> valuable feedback.
>
> Here is a brief summary of our tentative conclusions. Please correct me
> if anything is misrepresented (details in references):
>
> * Zswap tiering [2]:
>   Zswap can itself be a tier (typically the fastest one). But, until vswap lands,
>   zswap cannot be the only allowed tier,
>   since it still needs a physical device for allocation;
>   that restriction can be lifted once vswap is supported.

Does this series support zswap being a tier? I cannot find any mention
of zswap in the patches.