ANDROID: mm: create vendor hooks for do_shrink_slab()

The hook function: trace_android_vh_do_shrink_slab is added inside
of the function do_shrink_slab() to changed the numbers of page to
be reclaimed from kernel.

Bug: 279793370
Change-Id: I7c0b955be97f841c69bc99a152b59ed9823707ed
Signed-off-by: Dezhi Huang <huangdezhi@hihonor.com>
(cherry picked from commit aa254e44109ec3f608782cb627ede314f9eef0c6)

drivers/android/vendor_hooks.c

@@ -188,6 +188,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_free_oem_binder_struct);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_special_task);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_binder_buffer_release);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_mglru_should_abort_scan);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_do_shrink_slab);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_check_folio_look_around_ref);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_look_around);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_look_around_migrate_folio);

include/trace/hooks/vmscan.h

@@ -37,6 +37,9 @@ DECLARE_HOOK(android_vh_mglru_should_abort_scan,
 DECLARE_HOOK(android_vh_should_memcg_bypass,
 	TP_PROTO(struct mem_cgroup *memcg, int priority, bool *bypass),
 	TP_ARGS(memcg, priority, bypass));
+DECLARE_HOOK(android_vh_do_shrink_slab,
+	TP_PROTO(struct shrinker *shrinker, long *freeable),
+	TP_ARGS(shrinker, freeable));
 #endif /* _TRACE_HOOK_VMSCAN_H */
 /* This part must be outside protection */
 #include <trace/define_trace.h>

mm/shrinker.c

@@ -5,6 +5,9 @@
 #include <linux/rculist.h>
 #include <trace/events/vmscan.h>
 
+#undef CREATE_TRACE_POINTS
+#include <trace/hooks/vmscan.h>
+
 #include "internal.h"
 
 LIST_HEAD(shrinker_list);
@@ -382,6 +385,7 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl,
 	long scanned = 0, next_deferred;
 
 	freeable = shrinker->count_objects(shrinker, shrinkctl);
+	trace_android_vh_do_shrink_slab(shrinker, &freeable);
 	if (freeable == 0 || freeable == SHRINK_EMPTY)
 		return freeable;