mm/vmscan: add page demotion counter

Account the number of demoted pages.

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()
]

Link: https://lkml.kernel.org/r/20210721063926.3024591-5-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-6-ying.huang@intel.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Wei Xu <weixugc@google.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index ae0dd19..a185cc7 100644 (file)
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -33,6 +33,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
                PGREUSE,
                PGSTEAL_KSWAPD,
                PGSTEAL_DIRECT,
+               PGDEMOTE_KSWAPD,
+               PGDEMOTE_DIRECT,
                PGSCAN_KSWAPD,
                PGSCAN_DIRECT,
                PGSCAN_DIRECT_THROTTLE,

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f26b247..88593b8 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1318,6 +1318,11 @@ static unsigned int demote_page_list(struct list_head *demote_pages,
                            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 --git a/mm/vmstat.c b/mm/vmstat.c
index b0534e0..ec5a2e7 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1217,6 +1217,8 @@ const char * const vmstat_text[] = {
        "pgreuse",
        "pgsteal_kswapd",
        "pgsteal_direct",
+       "pgdemote_kswapd",
+       "pgdemote_direct",
        "pgscan_kswapd",
        "pgscan_direct",
        "pgscan_direct_throttle",