Re: [PATCH v2 3/3] mm/mglru: add tracepoint for inc_max_seq()

[Baolin Wang]

On 9/11/26 6:29 PM, Ridong Chen wrote:
> From: Ridong Chen <chenridong@xxxxxxxxxx>
>
> Aging in MGLRU advances max_seq via inc_max_seq(), creating a new
> youngest generation. There is currently no tracepoint on this path, so
> the moment a new generation is created, and how the min_seq of each type
> trails behind it, cannot be observed as it happens.
>
> Add mm_mglru_inc_max_seq, emitted right after max_seq is bumped, with
> the memcg id, the new max_seq, the anon and file min_seq, and the number
> of pages in each generation for both types, summed over zones the same
> way the debugfs lru_gen file reports them. The nr_anon/nr_file arrays are
> indexed by generation slot, so the emitted max_seq/min_seq say which slot
> holds which seq. They are printed with __print_array(), so the output is
> hex and its length follows MAX_NR_GENS automatically. Paired with the
> mm_mglru_scan_folios tracepoint it makes the full aging-to-eviction
> window observable per memcg.
>
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Ridong Chen <chenridong@xxxxxxxxxx>
> ---

Make sense to me.
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>