[PATCH -next 2/2] mm: vmscan: add new event to trace shrink lru

[Bixuan Cui]

From: cuibixuan <cuibixuan@xxxxxxxx>

Add a new event to calculate the shrink_inactive_list()/shrink_active_list()
execution time.

Example of output:
         kswapd0-103     [007] .....  1098.353020: mm_vmscan_lru_shrink_active_start: nid=0
         kswapd0-103     [007] .....  1098.353040: mm_vmscan_lru_shrink_active_end: nid=0 nr_taken=32 nr_active=0 nr_deactivated=32 nr_referenced=0 priority=6 flags=RECLAIM_WB_FILE|RECLAIM_WB_ASYNC
         kswapd0-103     [007] .....  1098.353040: mm_vmscan_lru_shrink_inactive_start: nid=0
         kswapd0-103     [007] .....  1098.353094: mm_vmscan_lru_shrink_inactive_end: nid=0 nr_scanned=32 nr_reclaimed=0 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=32 nr_unmap_fail=0 priority=6 flags=RECLAIM_WB_ANON|RECLAIM_WB_ASYNC
         kswapd0-103     [007] .....  1098.353094: mm_vmscan_lru_shrink_inactive_start: nid=0
         kswapd0-103     [007] .....  1098.353162: mm_vmscan_lru_shrink_inactive_end: nid=0 nr_scanned=32 nr_reclaimed=21 nr_dirty=0 nr_writeback=0 nr_congested=0 nr_immediate=0 nr_activate_anon=0 nr_activate_file=0 nr_ref_keep=11 nr_unmap_fail=0 priority=6 flags=RECLAIM_WB_FILE|RECLAIM_WB_ASYNC

Signed-off-by: Bixuan Cui <cuibixuan@xxxxxxxx>
---
 include/trace/events/vmscan.h | 38 +++++++++++++++++++++++++++++++++--
 mm/vmscan.c                   |  8 ++++++--
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 406faa5591c1..9809d158f968 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -395,7 +395,24 @@ TRACE_EVENT(mm_vmscan_write_folio,
 		show_reclaim_flags(__entry->reclaim_flags))
 );
 
-TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
+TRACE_EVENT(mm_vmscan_lru_shrink_inactive_start,
+
+	TP_PROTO(int nid),
+
+	TP_ARGS(nid),
+
+	TP_STRUCT__entry(
+		__field(int, nid)
+	),
+
+	TP_fast_assign(
+		__entry->nid = nid;
+	),
+
+	TP_printk("nid=%d", __entry->nid)
+);
+
+TRACE_EVENT(mm_vmscan_lru_shrink_inactive_end,
 
 	TP_PROTO(int nid,
 		unsigned long nr_scanned, unsigned long nr_reclaimed,
@@ -446,7 +463,24 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
 		show_reclaim_flags(__entry->reclaim_flags))
 );
 
-TRACE_EVENT(mm_vmscan_lru_shrink_active,
+TRACE_EVENT(mm_vmscan_lru_shrink_active_start,
+
+	TP_PROTO(int nid),
+
+	TP_ARGS(nid),
+
+	TP_STRUCT__entry(
+		__field(int, nid)
+	),
+
+	TP_fast_assign(
+		__entry->nid = nid;
+	),
+
+	TP_printk("nid=%d", __entry->nid)
+);
+
+TRACE_EVENT(mm_vmscan_lru_shrink_active_end,
 
 	TP_PROTO(int nid, unsigned long nr_taken,
 		unsigned long nr_active, unsigned long nr_deactivated,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4e3b835c6b4a..73e690b3ce68 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1906,6 +1906,8 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan,
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 	bool stalled = false;
 
+	trace_mm_vmscan_lru_shrink_inactive_start(pgdat->node_id);
+
 	while (unlikely(too_many_isolated(pgdat, file, sc))) {
 		if (stalled)
 			return 0;
@@ -1990,7 +1992,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan,
 	if (file)
 		sc->nr.file_taken += nr_taken;
 
-	trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
+	trace_mm_vmscan_lru_shrink_inactive_end(pgdat->node_id,
 			nr_scanned, nr_reclaimed, &stat, sc->priority, file);
 	return nr_reclaimed;
 }
@@ -2028,6 +2030,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
 	int file = is_file_lru(lru);
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 
+	trace_mm_vmscan_lru_shrink_active_start(pgdat->node_id);
+
 	lru_add_drain();
 
 	spin_lock_irq(&lruvec->lru_lock);
@@ -2107,7 +2111,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
 		lru_note_cost(lruvec, file, 0, nr_rotated);
 	mem_cgroup_uncharge_list(&l_active);
 	free_unref_page_list(&l_active);
-	trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_taken, nr_activate,
+	trace_mm_vmscan_lru_shrink_active_end(pgdat->node_id, nr_taken, nr_activate,
 			nr_deactivate, nr_rotated, sc->priority, file);
 }
 
-- 
2.39.0