ANDROID: vendor_hooks: bypass shrink slab

Add hooks for bypass shrink slab.

Bug: 185951972
(cherry picked from commit 396a6adfd31573ee8f53a86f84372cfb4d228e95)

Change-Id: I343e02ae5cd6d076d525d0e4bfc09ecdfeda1d7b
Signed-off-by: wudean <dean.wu@vivo.com>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 83e3570..de68f287 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -908,6 +908,11 @@ unsigned long shrink_slab(gfp_t gfp_mask, int nid,
 {
 	unsigned long ret, freed = 0;
 	struct shrinker *shrinker;
+	bool bypass = false;
+
+	trace_android_vh_shrink_slab_bypass(gfp_mask, nid, memcg, priority, &bypass);
+	if (bypass)
+		return 0;
 
 	/*
 	 * The root memcg might be allocated even though memcg is disabled