[PATCH REBASED 1/4] mm: Move recent_rotated pages calculation to shrink_inactive_list()

[Kirill Tkhai <ktkhai@virtuozzo.com>]

The patch moves the calculation from putback_inactive_pages()
to shrink_inactive_list(). This makes putback_inactive_pages()
looking more similar to move_active_pages_to_lru().

To do that, we account activated pages in reclaim_stat::nr_activate.
Since a page may change its LRU type from anon to file cache
inside shrink_page_list() (see ClearPageSwapBacked()), we have to
account pages for the both types. So, nr_activate becomes an array.

Previously we used nr_activate to account PGACTIVATE events, but now
we account them into pgactivate variable (since they are about
number of pages in general, not about sum of hpage_nr_pages).

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>

v2.5: Update comment.
v2:   Update trace events.
---
 .../trace/postprocess/trace-vmscan-postprocess.pl  |    7 ++++---
 include/linux/vmstat.h                             |    2 +-
 include/trace/events/vmscan.h                      |   13 ++++++++-----
 mm/vmscan.c                                        |   15 +++++++--------
 4 files changed, 20 insertions(+), 17 deletions(-)

diff --git a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
index 66bfd8396877..995da15b16ca 100644
--- a/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
+++ b/Documentation/trace/postprocess/trace-vmscan-postprocess.pl
@@ -113,7 +113,7 @@ my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)';
 my $regex_kswapd_sleep_default = 'nid=([0-9]*)';
 my $regex_wakeup_kswapd_default = 'nid=([0-9]*) zid=([0-9]*) order=([0-9]*) gfp_flags=([A-Z_|]*)';
 my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) classzone_idx=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_skipped=([0-9]*) nr_taken=([0-9]*) lru=([a-z_]*)';
-my $regex_lru_shrink_inactive_default = 'nid=([0-9]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) nr_dirty=([0-9]*) nr_writeback=([0-9]*) nr_congested=([0-9]*) nr_immediate=([0-9]*) nr_activate=([0-9]*) nr_ref_keep=([0-9]*) nr_unmap_fail=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)';
+my $regex_lru_shrink_inactive_default = 'nid=([0-9]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) nr_dirty=([0-9]*) nr_writeback=([0-9]*) nr_congested=([0-9]*) nr_immediate=([0-9]*) nr_activate_anon=([0-9]*) nr_activate_file=([0-9]*) nr_ref_keep=([0-9]*) nr_unmap_fail=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)';
 my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_scanned=([0-9]*) nr_rotated=([0-9]*) priority=([0-9]*)';
 my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)';
 
@@ -212,7 +212,8 @@ $regex_lru_shrink_inactive = generate_traceevent_regex(
 			"vmscan/mm_vmscan_lru_shrink_inactive",
 			$regex_lru_shrink_inactive_default,
 			"nid", "nr_scanned", "nr_reclaimed", "nr_dirty", "nr_writeback",
-			"nr_congested", "nr_immediate", "nr_activate", "nr_ref_keep",
+			"nr_congested", "nr_immediate", "nr_activate_anon",
+			"nr_activate_file", "nr_ref_keep",
 			"nr_unmap_fail", "priority", "flags");
 $regex_lru_shrink_active = generate_traceevent_regex(
 			"vmscan/mm_vmscan_lru_shrink_active",
@@ -407,7 +408,7 @@ sub process_events {
 			}
 
 			my $nr_reclaimed = $3;
-			my $flags = $12;
+			my $flags = $13;
 			my $file = 0;
 			if ($flags =~ /RECLAIM_WB_FILE/) {
 				$file = 1;
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 2db8d60981fe..bdeda4b079fe 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -26,7 +26,7 @@ struct reclaim_stat {
 	unsigned nr_congested;
 	unsigned nr_writeback;
 	unsigned nr_immediate;
-	unsigned nr_activate;
+	unsigned nr_activate[2];
 	unsigned nr_ref_keep;
 	unsigned nr_unmap_fail;
 };
diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index a1cb91342231..4f0e45e90cfc 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -358,7 +358,8 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
 		__field(unsigned long, nr_writeback)
 		__field(unsigned long, nr_congested)
 		__field(unsigned long, nr_immediate)
-		__field(unsigned long, nr_activate)
+		__field(unsigned int, nr_activate0)
+		__field(unsigned int, nr_activate1)
 		__field(unsigned long, nr_ref_keep)
 		__field(unsigned long, nr_unmap_fail)
 		__field(int, priority)
@@ -373,20 +374,22 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
 		__entry->nr_writeback = stat->nr_writeback;
 		__entry->nr_congested = stat->nr_congested;
 		__entry->nr_immediate = stat->nr_immediate;
-		__entry->nr_activate = stat->nr_activate;
+		__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;
 		__entry->priority = priority;
 		__entry->reclaim_flags = trace_shrink_flags(file);
 	),
 
-	TP_printk("nid=%d nr_scanned=%ld nr_reclaimed=%ld nr_dirty=%ld nr_writeback=%ld nr_congested=%ld nr_immediate=%ld nr_activate=%ld nr_ref_keep=%ld nr_unmap_fail=%ld priority=%d flags=%s",
+	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 priority=%d flags=%s",
 		__entry->nid,
 		__entry->nr_scanned, __entry->nr_reclaimed,
 		__entry->nr_dirty, __entry->nr_writeback,
 		__entry->nr_congested, __entry->nr_immediate,
-		__entry->nr_activate, __entry->nr_ref_keep,
-		__entry->nr_unmap_fail, __entry->priority,
+		__entry->nr_activate0, __entry->nr_activate1,
+		__entry->nr_ref_keep, __entry->nr_unmap_fail,
+		__entry->priority,
 		show_reclaim_flags(__entry->reclaim_flags))
 );
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 07f74e9507b6..e610737b36df 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1107,6 +1107,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
 	unsigned nr_reclaimed = 0;
+	unsigned pgactivate = 0;
 
 	memset(stat, 0, sizeof(*stat));
 	cond_resched();
@@ -1466,8 +1467,10 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 			try_to_free_swap(page);
 		VM_BUG_ON_PAGE(PageActive(page), page);
 		if (!PageMlocked(page)) {
+			int type = page_is_file_cache(page);
 			SetPageActive(page);
-			stat->nr_activate++;
+			pgactivate++;
+			stat->nr_activate[type] += hpage_nr_pages(page);
 			count_memcg_page_event(page, PGACTIVATE);
 		}
 keep_locked:
@@ -1482,7 +1485,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 	free_unref_page_list(&free_pages);
 
 	list_splice(&ret_pages, page_list);
-	count_vm_events(PGACTIVATE, stat->nr_activate);
+	count_vm_events(PGACTIVATE, pgactivate);
 
 	return nr_reclaimed;
 }
@@ -1807,7 +1810,6 @@ static int too_many_isolated(struct pglist_data *pgdat, int file,
 static noinline_for_stack void
 putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
 {
-	struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 	LIST_HEAD(pages_to_free);
 
@@ -1833,11 +1835,6 @@ putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
 		lru = page_lru(page);
 		add_page_to_lru_list(page, lruvec, lru);
 
-		if (is_active_lru(lru)) {
-			int file = is_file_lru(lru);
-			int numpages = hpage_nr_pages(page);
-			reclaim_stat->recent_rotated[file] += numpages;
-		}
 		if (put_page_testzero(page)) {
 			__ClearPageLRU(page);
 			__ClearPageActive(page);
@@ -1945,6 +1942,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 		count_memcg_events(lruvec_memcg(lruvec), PGSTEAL_DIRECT,
 				   nr_reclaimed);
 	}
+	reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
+	reclaim_stat->recent_rotated[1] = stat.nr_activate[1];
 
 	putback_inactive_pages(lruvec, &page_list);