Re: [PATCH v2] mm: drop the 'anon_' prefix for swap-out mTHP counters

[Barry Song]

On Thu, May 23, 2024 at 2:37 PM Baolin Wang
<baolin.wang@xxxxxxxxxxxxxxxxx> wrote:
>
> The mTHP swap related counters: 'anon_swpout' and 'anon_swpout_fallback' are
> confusing with an 'anon_' prefix, since the shmem can swap out non-anonymous
> pages. So drop the 'anon_' prefix to keep consistent with the old swap counter
> names.
>
> Suggested-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>

Acked-by: Barry Song <baohua@xxxxxxxxxx>

> ---
> Hi Andrew,
>
> Hope this patch can be merged into kernel 6.10-rc to maintain ABI compatibility.
> Thanks.
>
> Changes from v1:
>  - Update the documentation per Barry Song.
> ---
>  Documentation/admin-guide/mm/transhuge.rst | 4 ++--
>  include/linux/huge_mm.h                    | 4 ++--
>  mm/huge_memory.c                           | 8 ++++----
>  mm/page_io.c                               | 2 +-
>  mm/vmscan.c                                | 2 +-
>  5 files changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index 076443cc10a6..d414d3f5592a 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -467,11 +467,11 @@ anon_fault_fallback_charge
>         instead falls back to using huge pages with lower orders or
>         small pages even though the allocation was successful.
>
> -anon_swpout
> +swpout
>         is incremented every time a huge page is swapped out in one
>         piece without splitting.
>
> -anon_swpout_fallback
> +swpout_fallback
>         is incremented if a huge page has to be split before swapout.
>         Usually because failed to allocate some continuous swap space
>         for the huge page.
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index c8d3ec116e29..8c72d3786583 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -269,8 +269,8 @@ enum mthp_stat_item {
>         MTHP_STAT_ANON_FAULT_ALLOC,
>         MTHP_STAT_ANON_FAULT_FALLBACK,
>         MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE,
> -       MTHP_STAT_ANON_SWPOUT,
> -       MTHP_STAT_ANON_SWPOUT_FALLBACK,
> +       MTHP_STAT_SWPOUT,
> +       MTHP_STAT_SWPOUT_FALLBACK,
>         __MTHP_STAT_COUNT
>  };
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 317de2afd371..89932fd0f62e 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -558,15 +558,15 @@ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
>  DEFINE_MTHP_STAT_ATTR(anon_fault_alloc, MTHP_STAT_ANON_FAULT_ALLOC);
>  DEFINE_MTHP_STAT_ATTR(anon_fault_fallback, MTHP_STAT_ANON_FAULT_FALLBACK);
>  DEFINE_MTHP_STAT_ATTR(anon_fault_fallback_charge, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE);
> -DEFINE_MTHP_STAT_ATTR(anon_swpout, MTHP_STAT_ANON_SWPOUT);
> -DEFINE_MTHP_STAT_ATTR(anon_swpout_fallback, MTHP_STAT_ANON_SWPOUT_FALLBACK);
> +DEFINE_MTHP_STAT_ATTR(swpout, MTHP_STAT_SWPOUT);
> +DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK);
>
>  static struct attribute *stats_attrs[] = {
>         &anon_fault_alloc_attr.attr,
>         &anon_fault_fallback_attr.attr,
>         &anon_fault_fallback_charge_attr.attr,
> -       &anon_swpout_attr.attr,
> -       &anon_swpout_fallback_attr.attr,
> +       &swpout_attr.attr,
> +       &swpout_fallback_attr.attr,
>         NULL,
>  };
>
> diff --git a/mm/page_io.c b/mm/page_io.c
> index 46c603dddf04..0a150c240bf4 100644
> --- a/mm/page_io.c
> +++ b/mm/page_io.c
> @@ -217,7 +217,7 @@ static inline void count_swpout_vm_event(struct folio *folio)
>                 count_memcg_folio_events(folio, THP_SWPOUT, 1);
>                 count_vm_event(THP_SWPOUT);
>         }
> -       count_mthp_stat(folio_order(folio), MTHP_STAT_ANON_SWPOUT);
> +       count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
>  #endif
>         count_vm_events(PSWPOUT, folio_nr_pages(folio));
>  }
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 6981a71c8ef0..18b796605aa5 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1244,7 +1244,7 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
>                                                         THP_SWPOUT_FALLBACK, 1);
>                                                 count_vm_event(THP_SWPOUT_FALLBACK);
>                                         }
> -                                       count_mthp_stat(order, MTHP_STAT_ANON_SWPOUT_FALLBACK);
> +                                       count_mthp_stat(order, MTHP_STAT_SWPOUT_FALLBACK);
>  #endif
>                                         if (!add_to_swap(folio))
>                                                 goto activate_locked_split;
> --
> 2.39.3
>