Re: [PATCH RFC 00/32] mm/mglru: MGLRU-FG and refault distance support

[Kairui Song]

Joanne Koong <joannelkoong@xxxxxxxxx> 于 2026年7月23日周四 08:49写道：
>
> Gotcha. Can I ask what speaks against having the flags unification
> work ordered first, with the MGLRU-FG patches based on top of that and
> submitted in parallel as a separate series? It seems like the two
> could be reviewed upstream concurrently, and I think that would make
> the MGLRU-FG series easier to review with it on top of the flags
> cleanup, and freeing the two page flags seems like a sweet win on its
> own :) Is your concern that the FG series would then be gated on the
> flag series landing and you anticipate that the flag series would take
> longer to land than the FG series?

Hi,

That's not how it works, though. Without the MGLRU-FG, it takes four
bits for tracking the tier and these two flag bits have special
meanings. After FG, only three bits are needed and these two original
flag bits are just the lower two bits of a three-bit counter now. So,
there is an advantage to rearranging them together and removing the
single-bit (flag) operations to always use them as a whole. Before
that, that conversion will actual make thing more ugly.

BTW will there be any feature change with your splitting plan? If
there is no feature change, that should be easy to review.