On Fri, Sep 13, 2024 at 8:21 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. +1 - this is also useful for zswap shrinker enablement, after which an anon page can be loaded back in either from swap or zswap. Differentiating these two situations helps a lot with performance regression diagnostics. We have host level metrics, but they become less useful when we combine workloads with different characteristics in the same host. > > Link: https://lkml.kernel.org/r/20240830082244.156923-1-jingxiangzeng.cas@xxxxxxxxx > Signed-off-by: Jingxiang Zeng <linuszeng@xxxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxxxx> > Cc: Muchun Song <muchun.song@xxxxxxxxx> > Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx> > Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > mm/memcontrol.c | 2 ++ > mm/page_io.c | 4 ++++ > 2 files changed, 6 insertions(+) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 6efbfc9399d0..dbc1d43a5c4c 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); Not related to this patch, but why does the global stats not take into account large folios here... `count_vm_event(PSWPIN);`? Acked-by: Nhat Pham <nphamcs@xxxxxxxxx>
