ANDROID: vendor_hooks: bypass shrink slab

Add hooks for bypass shrink slab.

Bug: 185951972
Bug: 395197442
Change-Id: I343e02ae5cd6d076d525d0e4bfc09ecdfeda1d7b
Signed-off-by: wudean <dean.wu@vivo.com>
Signed-off-by: wengle <wengle@oppo.com>

drivers/android/vendor_hooks.c

@@ -175,6 +175,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_should_alloc_pages_retry);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_unreserve_highatomic_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rmqueue_bulk_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_hw_protection_shutdown);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_shrink_slab_bypass);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_insert);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_node_delete);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_node_replace);

include/trace/hooks/vmscan.h

@@ -56,6 +56,9 @@ enum scan_balance;
 DECLARE_HOOK(android_vh_tune_scan_type,
 	TP_PROTO(enum scan_balance *scan_type),
 	TP_ARGS(scan_type));
+DECLARE_HOOK(android_vh_shrink_slab_bypass,
+	TP_PROTO(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg, int priority, bool *bypass),
+	TP_ARGS(gfp_mask, nid, memcg, priority, bypass));
 #endif /* _TRACE_HOOK_VMSCAN_H */
 /* This part must be outside protection */
 #include <trace/define_trace.h>

mm/shrinker.c

@@ -620,6 +620,11 @@ unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
 {
 	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