[PATCH RFC v3 5/7] mm/vmscan: pass scan_control to the LRU isolate/shrink tracepoints

[Ridong Chen <ridong.chen@linux.dev>]

From: Ridong Chen <chenridong@xiaomi.com>

mm_vmscan_lru_isolate, mm_vmscan_lru_shrink_inactive and
mm_vmscan_lru_shrink_active spell out reclaim state (reclaim_idx, order,
priority) as individual arguments, all of which the caller already holds
in struct scan_control. Now that the struct is visible from the trace
header, pass sc directly and pick the fields out in TP_fast_assign.

No functional change. The tracefs event format (TP_STRUCT__entry and
TP_printk) is unchanged, so tracefs-based consumers are unaffected.
BPF programs attached via raw_tp/tp_btf see the new TP_PROTO and need
to be adjusted; tracepoints are not a stable ABI (see
Documentation/bpf/bpf_design_QA.rst).

Assisted-by: LLM
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
---
 mm/trace_vmscan.h | 31 +++++++++++++++----------------
 mm/vmscan.c       | 14 +++++++-------
 2 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/mm/trace_vmscan.h b/mm/trace_vmscan.h
index 28561fda83b3..aa27cb9524bb 100644
--- a/mm/trace_vmscan.h
+++ b/mm/trace_vmscan.h
@@ -350,15 +350,14 @@ TRACE_EVENT(mm_shrink_slab_end,
 );
 
 TRACE_EVENT(mm_vmscan_lru_isolate,
-	TP_PROTO(int highest_zoneidx,
-		int order,
-		unsigned long nr_requested,
-		unsigned long nr_scanned,
-		unsigned long nr_skipped,
-		unsigned long nr_taken,
-		int lru),
+	TP_PROTO(struct scan_control *sc,
+		 unsigned long nr_requested,
+		 unsigned long nr_scanned,
+		 unsigned long nr_skipped,
+		 unsigned long nr_taken,
+		 int lru),
 
-	TP_ARGS(highest_zoneidx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, lru),
+	TP_ARGS(sc, nr_requested, nr_scanned, nr_skipped, nr_taken, lru),
 
 	TP_STRUCT__entry(
 		__field(int, highest_zoneidx)
@@ -371,8 +370,8 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
 	),
 
 	TP_fast_assign(
-		__entry->highest_zoneidx = highest_zoneidx;
-		__entry->order = order;
+		__entry->highest_zoneidx = sc->reclaim_idx;
+		__entry->order = sc->order;
 		__entry->nr_requested = nr_requested;
 		__entry->nr_scanned = nr_scanned;
 		__entry->nr_skipped = nr_skipped;
@@ -466,9 +465,9 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
 
 	TP_PROTO(int nid,
 		unsigned long nr_scanned, unsigned long nr_reclaimed,
-		struct reclaim_stat *stat, int priority, int file),
+		struct reclaim_stat *stat, struct scan_control *sc, int file),
 
-	TP_ARGS(nid, nr_scanned, nr_reclaimed, stat, priority, file),
+	TP_ARGS(nid, nr_scanned, nr_reclaimed, stat, sc, file),
 
 	TP_STRUCT__entry(
 		__field(int, nid)
@@ -498,7 +497,7 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive,
 		__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->priority = sc->priority;
 		__entry->reclaim_flags = trace_reclaim_flags(file);
 	),
 
@@ -517,9 +516,9 @@ TRACE_EVENT(mm_vmscan_lru_shrink_active,
 
 	TP_PROTO(int nid, unsigned long nr_taken,
 		unsigned long nr_active, unsigned long nr_deactivated,
-		unsigned long nr_referenced, int priority, int file),
+		unsigned long nr_referenced, struct scan_control *sc, int file),
 
-	TP_ARGS(nid, nr_taken, nr_active, nr_deactivated, nr_referenced, priority, file),
+	TP_ARGS(nid, nr_taken, nr_active, nr_deactivated, nr_referenced, sc, file),
 
 	TP_STRUCT__entry(
 		__field(int, nid)
@@ -537,7 +536,7 @@ TRACE_EVENT(mm_vmscan_lru_shrink_active,
 		__entry->nr_active = nr_active;
 		__entry->nr_deactivated = nr_deactivated;
 		__entry->nr_referenced = nr_referenced;
-		__entry->priority = priority;
+		__entry->priority = sc->priority;
 		__entry->reclaim_flags = trace_reclaim_flags(file);
 	),
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2979d0d819a8..c25ba910149d 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1764,7 +1764,7 @@ static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
 		}
 	}
 	*nr_scanned = total_scan;
-	trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan,
+	trace_mm_vmscan_lru_isolate(sc, nr_to_scan,
 				    total_scan, skipped, nr_taken, lru);
 	update_lru_sizes(lruvec, lru, nr_zone_taken);
 	return nr_taken;
@@ -2053,7 +2053,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan,
 
 	handle_reclaim_writeback(nr_taken, pgdat, sc, &stat);
 	trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
-			nr_scanned, nr_reclaimed, &stat, sc->priority, file);
+			nr_scanned, nr_reclaimed, &stat, sc, file);
 	return nr_reclaimed;
 }
 
@@ -2160,7 +2160,7 @@ static void shrink_active_list(unsigned long nr_to_scan,
 		mod_lruvec_state(lruvec, PGROTATE_ANON + file, nr_rotated);
 
 	trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_taken, nr_activate,
-			nr_deactivate, nr_rotated, sc->priority, file);
+			nr_deactivate, nr_rotated, sc, file);
 }
 
 static unsigned int reclaim_folio_list(struct list_head *folio_list,
@@ -4850,9 +4850,9 @@ static int scan_folios(unsigned long nr_to_scan, struct lruvec *lruvec,
 	mod_lruvec_state(lruvec, item, isolated);
 	mod_lruvec_state(lruvec, PGREFILL, sorted);
 	mod_lruvec_state(lruvec, PGSCAN_ANON + type, isolated);
-	trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan,
-				scanned, skipped, isolated,
-				type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
+	trace_mm_vmscan_lru_isolate(sc, nr_to_scan,
+				    scanned, skipped, isolated,
+				    type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
 
 	*isolatedp = isolated;
 	return scanned;
@@ -4991,7 +4991,7 @@ static int evict_folios(unsigned long nr_to_scan, struct lruvec *lruvec,
 	if (isolated)
 		handle_reclaim_writeback(isolated, pgdat, sc, &stat);
 	trace_mm_vmscan_lru_shrink_inactive(pgdat->node_id,
-			type_scanned, reclaimed, &stat, sc->priority,
+			type_scanned, reclaimed, &stat, sc,
 			type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON);
 
 	list_for_each_entry_safe_reverse(folio, next, &list, lru) {
-- 
2.34.1