Re: [PATCH] mm/memcontrol: add per-memcg pgpgin/pswpin counter

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 30 Aug 2024 16:22:44 +0800 Jingxiang Zeng <jingxiangzeng.cas@gmail.com> wrote:

> From: Jingxiang Zeng <linuszeng@tencent.com>
> 
> In proactive memory reclamation scenarios, it is necessary to
> estimate the pswpin and pswpout metrics of the cgroup to
> determine whether to continue reclaiming anonymous pages in
> the current batch. This patch will collect these metrics and
> expose them.

Could we have some reviewer input on this please?

> diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
> index b37c0d870816..44803cbea38a 100644
> --- a/mm/memcontrol-v1.c
> +++ b/mm/memcontrol-v1.c
> @@ -2729,6 +2729,8 @@ static const char *const memcg1_stat_names[] = {
>  static const unsigned int memcg1_events[] = {
>  	PGPGIN,
>  	PGPGOUT,
> +	PSWPIN,
> +	PSWPOUT,
>  	PGFAULT,
>  	PGMAJFAULT,
>  };
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 087a8cb1a6d8..dde3d026f174 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -418,6 +418,8 @@ static const unsigned int memcg_vm_event_stat[] = {
>  	PGPGIN,
>  	PGPGOUT,
>  #endif
> +	PSWPIN,
> +	PSWPOUT,
>  	PGSCAN_KSWAPD,
>  	PGSCAN_DIRECT,
>  	PGSCAN_KHUGEPAGED,
> diff --git a/mm/page_io.c b/mm/page_io.c
> index b6f1519d63b0..4bc77d1c6bfa 100644
> --- a/mm/page_io.c
> +++ b/mm/page_io.c
> @@ -310,6 +310,7 @@ static inline void count_swpout_vm_event(struct folio *folio)
>  	}
>  	count_mthp_stat(folio_order(folio), MTHP_STAT_SWPOUT);
>  #endif
> +	count_memcg_folio_events(folio, PSWPOUT, folio_nr_pages(folio));
>  	count_vm_events(PSWPOUT, folio_nr_pages(folio));
>  }
>  
> @@ -505,6 +506,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
>  		for (p = 0; p < sio->pages; p++) {
>  			struct folio *folio = page_folio(sio->bvec[p].bv_page);
>  
> +			count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
>  			folio_mark_uptodate(folio);
>  			folio_unlock(folio);
>  		}
> @@ -588,6 +590,7 @@ static void swap_read_folio_bdev_sync(struct folio *folio,
>  	 * attempt to access it in the page fault retry time check.
>  	 */
>  	get_task_struct(current);
> +	count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
>  	count_vm_event(PSWPIN);
>  	submit_bio_wait(&bio);
>  	__end_swap_bio_read(&bio);
> @@ -603,6 +606,7 @@ static void swap_read_folio_bdev_async(struct folio *folio,
>  	bio->bi_iter.bi_sector = swap_folio_sector(folio);
>  	bio->bi_end_io = end_swap_bio_read;
>  	bio_add_folio_nofail(bio, folio, folio_size(folio), 0);
> +	count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
>  	count_vm_event(PSWPIN);
>  	submit_bio(bio);
>  }
> -- 
> 2.43.5
>