From: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Account the number of demoted pages into reclaim_state->nr_demoted. Add pgdemote_kswapd and pgdemote_direct VM counters showed in /proc/vmstat. [ daveh: - __count_vm_events() a bit, and made them look at the THP size directly rather than getting data from migrate_pages() ] Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Yang Shi <shy828301@xxxxxxxxx> Cc: Wei Xu <weixugc@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Huang Ying <ying.huang@xxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: osalvador <osalvador@xxxxxxx> -- Changes since 202010: * remove unused scan-control 'demoted' field --- b/include/linux/vm_event_item.h | 2 ++ b/mm/vmscan.c | 5 +++++ b/mm/vmstat.c | 2 ++ 3 files changed, 9 insertions(+) diff -puN include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter include/linux/vm_event_item.h --- a/include/linux/vm_event_item.h~mm-vmscan-add-page-demotion-counter 2021-03-31 15:17:17.079000248 -0700 +++ b/include/linux/vm_event_item.h 2021-03-31 15:17:17.101000248 -0700 @@ -33,6 +33,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PS PGREUSE, PGSTEAL_KSWAPD, PGSTEAL_DIRECT, + PGDEMOTE_KSWAPD, + PGDEMOTE_DIRECT, PGSCAN_KSWAPD, PGSCAN_DIRECT, PGSCAN_DIRECT_THROTTLE, diff -puN mm/vmscan.c~mm-vmscan-add-page-demotion-counter mm/vmscan.c --- a/mm/vmscan.c~mm-vmscan-add-page-demotion-counter 2021-03-31 15:17:17.081000248 -0700 +++ b/mm/vmscan.c 2021-03-31 15:17:17.109000248 -0700 @@ -1120,6 +1120,11 @@ static unsigned int demote_page_list(str target_nid, MIGRATE_ASYNC, MR_DEMOTION, &nr_succeeded); + if (current_is_kswapd()) + __count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded); + else + __count_vm_events(PGDEMOTE_DIRECT, nr_succeeded); + return nr_succeeded; } diff -puN mm/vmstat.c~mm-vmscan-add-page-demotion-counter mm/vmstat.c --- a/mm/vmstat.c~mm-vmscan-add-page-demotion-counter 2021-03-31 15:17:17.092000248 -0700 +++ b/mm/vmstat.c 2021-03-31 15:17:17.116000248 -0700 @@ -1259,6 +1259,8 @@ const char * const vmstat_text[] = { "pgreuse", "pgsteal_kswapd", "pgsteal_direct", + "pgdemote_kswapd", + "pgdemote_direct", "pgscan_kswapd", "pgscan_direct", "pgscan_direct_throttle", _