| Message ID | 20241011124928.1224813-1-jaewon31.kim@samsung.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] vmscan: add a vmscan event for reclaim_pages | expand |
On 10/11/24 14:49, Jaewon Kim wrote: > The reclaim_folio_list uses a dummy reclaim_stat and is not being > used. To know the memory stat, add a new trace event. This is useful how > how many pages are not reclaimed or why. > > This is an example. > mm_vmscan_reclaim_pages: nid=0 nr_scanned=112 nr_reclaimed=112 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=0 nr_unmap_fail=0 > > Currenlty reclaim_folio_list is only called by reclaim_pages, and > reclaim_pages is used by damon and madvise. In the latest Android, > reclaim_pages is also used by shmem to reclaim all pages in a > address_space. > > Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> > --- > v2: remove reclaim_stat_add function and call the trace on each node > v1: introduce a new trace event > --- > include/trace/events/vmscan.h | 45 +++++++++++++++++++++++++++++++++++ > mm/vmscan.c | 16 +++++++++---- > 2 files changed, 56 insertions(+), 5 deletions(-) > > diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h > index 1a488c30afa5..490958fa10de 100644 > --- a/include/trace/events/vmscan.h > +++ b/include/trace/events/vmscan.h > @@ -346,6 +346,51 @@ TRACE_EVENT(mm_vmscan_write_folio, > show_reclaim_flags(__entry->reclaim_flags)) > ); > > +TRACE_EVENT(mm_vmscan_reclaim_pages, > + > + TP_PROTO(int nid, > + unsigned long nr_scanned, unsigned long nr_reclaimed, > + struct reclaim_stat *stat), > + > + TP_ARGS(nid, nr_scanned, nr_reclaimed, stat), > + > + TP_STRUCT__entry( > + __field(int, nid) > + __field(unsigned long, nr_scanned) > + __field(unsigned long, nr_reclaimed) > + __field(unsigned long, nr_dirty) > + __field(unsigned long, nr_writeback) > + __field(unsigned long, nr_congested) > + __field(unsigned long, nr_immediate) > + __field(unsigned int, nr_activate0) > + __field(unsigned int, nr_activate1) > + __field(unsigned long, nr_ref_keep) > + __field(unsigned long, nr_unmap_fail) > + ), > + > + TP_fast_assign( > + __entry->nid = nid; > + __entry->nr_scanned = nr_scanned; > + __entry->nr_reclaimed = nr_reclaimed; > + __entry->nr_dirty = stat->nr_dirty; > + __entry->nr_writeback = stat->nr_writeback; > + __entry->nr_congested = stat->nr_congested; > + __entry->nr_immediate = stat->nr_immediate; > + __entry->nr_activate0 = stat->nr_activate[0]; > + __entry->nr_activate1 = stat->nr_activate[1]; > + __entry->nr_ref_keep = stat->nr_ref_keep; > + __entry->nr_unmap_fail = stat->nr_unmap_fail; > + ), > + > + TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld", > + __entry->nid, > + __entry->nr_scanned, __entry->nr_reclaimed, > + __entry->nr_dirty, __entry->nr_writeback, > + __entry->nr_congested, __entry->nr_immediate, > + __entry->nr_activate0, __entry->nr_activate1, > + __entry->nr_ref_keep, __entry->nr_unmap_fail) > +); > + > TRACE_EVENT(mm_vmscan_lru_shrink_inactive, > > TP_PROTO(int nid, > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 749cdc110c74..0c2c36bf4c5a 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2126,9 +2126,10 @@ static void shrink_active_list(unsigned long nr_to_scan, > } > > static unsigned int reclaim_folio_list(struct list_head *folio_list, > + unsigned int nr_scanned, > struct pglist_data *pgdat) > { > - struct reclaim_stat dummy_stat; > + struct reclaim_stat stat; > unsigned int nr_reclaimed; > struct folio *folio; > struct scan_control sc = { > @@ -2139,12 +2140,13 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, > .no_demotion = 1, > }; > > - nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true); > + nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &stat, true); > while (!list_empty(folio_list)) { > folio = lru_to_folio(folio_list); > list_del(&folio->lru); > folio_putback_lru(folio); > } > + trace_mm_vmscan_reclaim_pages(pgdat->node_id, nr_scanned, nr_reclaimed, &stat); Why is the new calculation of nr_scanned needed? Could you just take a delta of sc->nr_scanned, i.e. after - before calling shrink_folio_list() ? > > return nr_reclaimed; > } > @@ -2152,6 +2154,7 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, > unsigned long reclaim_pages(struct list_head *folio_list) > { > int nid; > + unsigned int nr_scanned = 0; > unsigned int nr_reclaimed = 0; > LIST_HEAD(node_folio_list); > unsigned int noreclaim_flag; > @@ -2168,15 +2171,18 @@ unsigned long reclaim_pages(struct list_head *folio_list) > if (nid == folio_nid(folio)) { > folio_clear_active(folio); > list_move(&folio->lru, &node_folio_list); > + nr_scanned += folio_nr_pages(folio); > continue; > } > > - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); > + nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned, > + NODE_DATA(nid)); > + nr_scanned = 0; > nid = folio_nid(lru_to_folio(folio_list)); > } while (!list_empty(folio_list)); > > - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); > - > + nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned, > + NODE_DATA(nid)); > memalloc_noreclaim_restore(noreclaim_flag); > > return nr_reclaimed;
>On 10/11/24 14:49, Jaewon Kim wrote: >> The reclaim_folio_list uses a dummy reclaim_stat and is not being >> used. To know the memory stat, add a new trace event. This is useful how >> how many pages are not reclaimed or why. >> >> This is an example. >> mm_vmscan_reclaim_pages: nid=0 nr_scanned=112 nr_reclaimed=112 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=0 nr_unmap_fail=0 >> >> Currenlty reclaim_folio_list is only called by reclaim_pages, and >> reclaim_pages is used by damon and madvise. In the latest Android, >> reclaim_pages is also used by shmem to reclaim all pages in a >> address_space. >> >> Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> >> --- >> v2: remove reclaim_stat_add function and call the trace on each node >> v1: introduce a new trace event >> --- >> include/trace/events/vmscan.h | 45 +++++++++++++++++++++++++++++++++++ >> mm/vmscan.c | 16 +++++++++---- >> 2 files changed, 56 insertions(+), 5 deletions(-) >> >> diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h >> index 1a488c30afa5..490958fa10de 100644 >> --- a/include/trace/events/vmscan.h >> +++ b/include/trace/events/vmscan.h >> @@ -346,6 +346,51 @@ TRACE_EVENT(mm_vmscan_write_folio, >> show_reclaim_flags(__entry->reclaim_flags)) >> ); >> >> +TRACE_EVENT(mm_vmscan_reclaim_pages, >> + >> + TP_PROTO(int nid, >> + unsigned long nr_scanned, unsigned long nr_reclaimed, >> + struct reclaim_stat *stat), >> + >> + TP_ARGS(nid, nr_scanned, nr_reclaimed, stat), >> + >> + TP_STRUCT__entry( >> + __field(int, nid) >> + __field(unsigned long, nr_scanned) >> + __field(unsigned long, nr_reclaimed) >> + __field(unsigned long, nr_dirty) >> + __field(unsigned long, nr_writeback) >> + __field(unsigned long, nr_congested) >> + __field(unsigned long, nr_immediate) >> + __field(unsigned int, nr_activate0) >> + __field(unsigned int, nr_activate1) >> + __field(unsigned long, nr_ref_keep) >> + __field(unsigned long, nr_unmap_fail) >> + ), >> + >> + TP_fast_assign( >> + __entry->nid = nid; >> + __entry->nr_scanned = nr_scanned; >> + __entry->nr_reclaimed = nr_reclaimed; >> + __entry->nr_dirty = stat->nr_dirty; >> + __entry->nr_writeback = stat->nr_writeback; >> + __entry->nr_congested = stat->nr_congested; >> + __entry->nr_immediate = stat->nr_immediate; >> + __entry->nr_activate0 = stat->nr_activate[0]; >> + __entry->nr_activate1 = stat->nr_activate[1]; >> + __entry->nr_ref_keep = stat->nr_ref_keep; >> + __entry->nr_unmap_fail = stat->nr_unmap_fail; >> + ), >> + >> + TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld", >> + __entry->nid, >> + __entry->nr_scanned, __entry->nr_reclaimed, >> + __entry->nr_dirty, __entry->nr_writeback, >> + __entry->nr_congested, __entry->nr_immediate, >> + __entry->nr_activate0, __entry->nr_activate1, >> + __entry->nr_ref_keep, __entry->nr_unmap_fail) >> +); >> + >> TRACE_EVENT(mm_vmscan_lru_shrink_inactive, >> >> TP_PROTO(int nid, >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index 749cdc110c74..0c2c36bf4c5a 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -2126,9 +2126,10 @@ static void shrink_active_list(unsigned long nr_to_scan, >> } >> >> static unsigned int reclaim_folio_list(struct list_head *folio_list, >> + unsigned int nr_scanned, >> struct pglist_data *pgdat) >> { >> - struct reclaim_stat dummy_stat; >> + struct reclaim_stat stat; >> unsigned int nr_reclaimed; >> struct folio *folio; >> struct scan_control sc = { >> @@ -2139,12 +2140,13 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, >> .no_demotion = 1, >> }; >> >> - nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true); >> + nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &stat, true); >> while (!list_empty(folio_list)) { >> folio = lru_to_folio(folio_list); >> list_del(&folio->lru); >> folio_putback_lru(folio); >> } >> + trace_mm_vmscan_reclaim_pages(pgdat->node_id, nr_scanned, nr_reclaimed, &stat); > >Why is the new calculation of nr_scanned needed? Could you just take a delta >of sc->nr_scanned, i.e. after - before calling shrink_folio_list() ? Oh correct. Except the case of (!folio_trylock(folio)), shrink_folio_list would count at sc->nr_scanned. I don't understand why we do not count this lock case though. Let me try to change as you suggested. I think without 'after - before', we can just use sc->nr_scanned after shrink_folio_list. Thank you > >> >> return nr_reclaimed; >> } >> @@ -2152,6 +2154,7 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, >> unsigned long reclaim_pages(struct list_head *folio_list) >> { >> int nid; >> + unsigned int nr_scanned = 0; >> unsigned int nr_reclaimed = 0; >> LIST_HEAD(node_folio_list); >> unsigned int noreclaim_flag; >> @@ -2168,15 +2171,18 @@ unsigned long reclaim_pages(struct list_head *folio_list) >> if (nid == folio_nid(folio)) { >> folio_clear_active(folio); >> list_move(&folio->lru, &node_folio_list); >> + nr_scanned += folio_nr_pages(folio); >> continue; >> } >> >> - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); >> + nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned, >> + NODE_DATA(nid)); >> + nr_scanned = 0; >> nid = folio_nid(lru_to_folio(folio_list)); >> } while (!list_empty(folio_list)); >> >> - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); >> - >> + nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned, >> + NODE_DATA(nid)); >> memalloc_noreclaim_restore(noreclaim_flag); >> >> return nr_reclaimed; >
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index 1a488c30afa5..490958fa10de 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -346,6 +346,51 @@ TRACE_EVENT(mm_vmscan_write_folio, show_reclaim_flags(__entry->reclaim_flags)) ); +TRACE_EVENT(mm_vmscan_reclaim_pages, + + TP_PROTO(int nid, + unsigned long nr_scanned, unsigned long nr_reclaimed, + struct reclaim_stat *stat), + + TP_ARGS(nid, nr_scanned, nr_reclaimed, stat), + + TP_STRUCT__entry( + __field(int, nid) + __field(unsigned long, nr_scanned) + __field(unsigned long, nr_reclaimed) + __field(unsigned long, nr_dirty) + __field(unsigned long, nr_writeback) + __field(unsigned long, nr_congested) + __field(unsigned long, nr_immediate) + __field(unsigned int, nr_activate0) + __field(unsigned int, nr_activate1) + __field(unsigned long, nr_ref_keep) + __field(unsigned long, nr_unmap_fail) + ), + + TP_fast_assign( + __entry->nid = nid; + __entry->nr_scanned = nr_scanned; + __entry->nr_reclaimed = nr_reclaimed; + __entry->nr_dirty = stat->nr_dirty; + __entry->nr_writeback = stat->nr_writeback; + __entry->nr_congested = stat->nr_congested; + __entry->nr_immediate = stat->nr_immediate; + __entry->nr_activate0 = stat->nr_activate[0]; + __entry->nr_activate1 = stat->nr_activate[1]; + __entry->nr_ref_keep = stat->nr_ref_keep; + __entry->nr_unmap_fail = stat->nr_unmap_fail; + ), + + TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate_anon=%d nr_activate_file=%d nr_ref_keep=%ld nr_unmap_fail=%ld", + __entry->nid, + __entry->nr_scanned, __entry->nr_reclaimed, + __entry->nr_dirty, __entry->nr_writeback, + __entry->nr_congested, __entry->nr_immediate, + __entry->nr_activate0, __entry->nr_activate1, + __entry->nr_ref_keep, __entry->nr_unmap_fail) +); + TRACE_EVENT(mm_vmscan_lru_shrink_inactive, TP_PROTO(int nid, diff --git a/mm/vmscan.c b/mm/vmscan.c index 749cdc110c74..0c2c36bf4c5a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2126,9 +2126,10 @@ static void shrink_active_list(unsigned long nr_to_scan, } static unsigned int reclaim_folio_list(struct list_head *folio_list, + unsigned int nr_scanned, struct pglist_data *pgdat) { - struct reclaim_stat dummy_stat; + struct reclaim_stat stat; unsigned int nr_reclaimed; struct folio *folio; struct scan_control sc = { @@ -2139,12 +2140,13 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, .no_demotion = 1, }; - nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &dummy_stat, true); + nr_reclaimed = shrink_folio_list(folio_list, pgdat, &sc, &stat, true); while (!list_empty(folio_list)) { folio = lru_to_folio(folio_list); list_del(&folio->lru); folio_putback_lru(folio); } + trace_mm_vmscan_reclaim_pages(pgdat->node_id, nr_scanned, nr_reclaimed, &stat); return nr_reclaimed; } @@ -2152,6 +2154,7 @@ static unsigned int reclaim_folio_list(struct list_head *folio_list, unsigned long reclaim_pages(struct list_head *folio_list) { int nid; + unsigned int nr_scanned = 0; unsigned int nr_reclaimed = 0; LIST_HEAD(node_folio_list); unsigned int noreclaim_flag; @@ -2168,15 +2171,18 @@ unsigned long reclaim_pages(struct list_head *folio_list) if (nid == folio_nid(folio)) { folio_clear_active(folio); list_move(&folio->lru, &node_folio_list); + nr_scanned += folio_nr_pages(folio); continue; } - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); + nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned, + NODE_DATA(nid)); + nr_scanned = 0; nid = folio_nid(lru_to_folio(folio_list)); } while (!list_empty(folio_list)); - nr_reclaimed += reclaim_folio_list(&node_folio_list, NODE_DATA(nid)); - + nr_reclaimed += reclaim_folio_list(&node_folio_list, nr_scanned, + NODE_DATA(nid)); memalloc_noreclaim_restore(noreclaim_flag); return nr_reclaimed;
The reclaim_folio_list uses a dummy reclaim_stat and is not being used. To know the memory stat, add a new trace event. This is useful how how many pages are not reclaimed or why. This is an example. mm_vmscan_reclaim_pages: nid=0 nr_scanned=112 nr_reclaimed=112 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=0 nr_unmap_fail=0 Currenlty reclaim_folio_list is only called by reclaim_pages, and reclaim_pages is used by damon and madvise. In the latest Android, reclaim_pages is also used by shmem to reclaim all pages in a address_space. Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> --- v2: remove reclaim_stat_add function and call the trace on each node v1: introduce a new trace event --- include/trace/events/vmscan.h | 45 +++++++++++++++++++++++++++++++++++ mm/vmscan.c | 16 +++++++++---- 2 files changed, 56 insertions(+), 5 deletions(-)