ANDROID: vendor_hooks: Add tune scan type hook in get_scan_count()

Add hook in get_scan_count() for oem to wield customized reclamation strategy

Bug: 294180281
Bug: 336401947
Change-Id: Ic54d35128e458661fc2b641809f5371b1d9a488e
Signed-off-by: Jiewen Wang <jiewen.wang@vivo.com>
Signed-off-by: huzhanyuan <huzhanyuan@oppo.com>

drivers/android/vendor_hooks.c

@@ -229,6 +229,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rmqueue_smallest_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_free_one_page_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_migration_target_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_adjust_alloc_flags);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tune_scan_type);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_wait_for_work);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_alloc_oem_binder_struct);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_transaction_received);

include/trace/hooks/vmscan.h

@@ -52,6 +52,10 @@ DECLARE_HOOK(android_vh_tune_scan_control,
 DECLARE_HOOK(android_vh_page_referenced_check_bypass,
 	TP_PROTO(struct folio *folio, unsigned long nr_to_scan, int lru, bool *bypass),
 	TP_ARGS(folio, nr_to_scan, lru, bypass));
+enum scan_balance;
+DECLARE_HOOK(android_vh_tune_scan_type,
+	TP_PROTO(enum scan_balance *scan_type),
+	TP_ARGS(scan_type));
 #endif /* _TRACE_HOOK_VMSCAN_H */
 /* This part must be outside protection */
 #include <trace/define_trace.h>

mm/vmscan.c

@@ -2508,6 +2508,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
 	fraction[1] = fp;
 	denominator = ap + fp;
 out:
+	trace_android_vh_tune_scan_type(&scan_balance);
 	for_each_evictable_lru(lru) {
 		bool file = is_file_lru(lru);
 		unsigned long lruvec_size;