Re: [PATCH v6 2/4] mm: swap: associate swap devices with tiers

[Baoquan He <baoquan.he@linux.dev>]

On 04/21/26 at 02:53pm, Youngjun Park wrote:
> This patch connects swap devices to the swap tier infrastructure,
> ensuring that devices are correctly assigned to tiers based on their
> priority.
> 
> A `tier_mask` is added to identify the tier membership of swap devices.
> Although tier-based allocation logic is not yet implemented, this
> mapping is necessary to track which tier a device belongs to. Upon
> activation, the device is assigned to a tier by matching its priority
> against the configured tier ranges.
> 
> The infrastructure allows dynamic modification of tiers, such as
> splitting or merging ranges. These operations are permitted provided
> that the tier assignment of already configured swap devices remains
> unchanged.
> 
> This patch also adds the documentation for the swap tier feature,
> covering the core concepts, sysfs interface usage, and configuration
> details.
> 
> Signed-off-by: Youngjun Park <youngjun.park@lge.com>
> ---
>  Documentation/mm/index.rst     |   1 +
>  Documentation/mm/swap-tier.rst | 159 +++++++++++++++++++++++++++++++++
>  MAINTAINERS                    |   1 +
>  include/linux/swap.h           |   1 +
>  mm/swap_state.c                |   2 +-
>  mm/swap_tier.c                 | 101 ++++++++++++++++++---
>  mm/swap_tier.h                 |  13 ++-
>  mm/swapfile.c                  |   2 +
>  8 files changed, 266 insertions(+), 14 deletions(-)
>  create mode 100644 Documentation/mm/swap-tier.rst

LGTM,

Reviewed-by: Baoquan He <baoquan.he@linux.dev>