On Fri, Aug 30, 2024 at 1:23 AM Jingxiang Zeng
<jingxiangzeng.cas@xxxxxxxxx> wrote:
>
> From: Jingxiang Zeng <linuszeng@xxxxxxxxxxx>
>
> 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 you add more details about the use case?
By "reclaiming anonymous pages", do you mean using memory.reclaim with
swappiness=200?
Why not just use PGPGOUT to figure out how many pages were reclaimed?
Do you find a significant amount of file pages getting reclaimed with
swappiness=200?
>
> Signed-off-by: Jingxiang Zeng <linuszeng@xxxxxxxxxxx>
> ---
> mm/memcontrol-v1.c | 2 ++
> mm/memcontrol.c | 2 ++
> mm/page_io.c | 4 ++++
> 3 files changed, 8 insertions(+)
>
> 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,
memory.reclaim is not exposed in cgroup v1, so assuming these are only
used for such proactive reclaim, we don't need to add them here.
> 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
>
>
