Fix BIHASH_KVP_CACHE_SIZE == 0 case

Setting the bucket-level LRU cache size to zero removes the
bucket-level LRU cache code.

Change-Id: Idf2e63d0d508675e957366515863766f79a3479c
Signed-off-by: Dave Barach <dbarach@cisco.com>

3 files changed, 37 insertions, 4 deletions

diff --git a/src/vppinfra/bihash_8_8.h b/src/vppinfra/bihash_8_8.h
index f81002d6..2deb64ef 100644
--- a/src/vppinfra/bihash_8_8.h
+++ b/src/vppinfra/bihash_8_8.h
@@ -18,7 +18,7 @@
 
 #define BIHASH_TYPE _8_8
 #define BIHASH_KVP_PER_PAGE 4
-#define BIHASH_KVP_CACHE_SIZE 5
+#define BIHASH_KVP_CACHE_SIZE 0
 
 #ifndef __included_bihash_8_8_h__
 #define __included_bihash_8_8_h__
diff --git a/src/vppinfra/bihash_template.c b/src/vppinfra/bihash_template.c
index b5eb379a..704d1659 100644
--- a/src/vppinfra/bihash_template.c
+++ b/src/vppinfra/bihash_template.c
@@ -430,7 +430,9 @@ int BV (clib_bihash_search)
   u64 hash;
   u32 bucket_index;
   BVT (clib_bihash_value) * v;
+#if BIHASH_KVP_CACHE_SIZE > 0
   BVT (clib_bihash_kv) * kvp;
+#endif
   BVT (clib_bihash_bucket) * b;
   int i, limit;
 
@@ -444,6 +446,7 @@ int BV (clib_bihash_search)
   if (b->offset == 0)
     return -1;
 
+#if BIHASH_KVP_CACHE_SIZE > 0
   /* Check the cache, if currently enabled */
   if (PREDICT_TRUE ((b->cache_lru & (1 << 15)) == 0))
     {
@@ -459,6 +462,7 @@ int BV (clib_bihash_search)
 	    }
 	}
     }
+#endif
 
   hash >>= h->log2_nbuckets;
 
@@ -472,9 +476,10 @@ int BV (clib_bihash_search)
     {
       if (BV (clib_bihash_key_compare) (v->kvp[i].key, search_key->key))
 	{
-	  u8 cache_slot;
 	  *valuep = v->kvp[i];
 
+#if BIHASH_KVP_CACHE_SIZE > 0
+	  u8 cache_slot;
 	  /* Shut off the cache */
 	  if (BV (clib_bihash_lock_bucket) (b))
 	    {
@@ -486,6 +491,7 @@ int BV (clib_bihash_search)
 	      BV (clib_bihash_unlock_bucket) (b);
 	      h->cache_misses++;
 	    }
+#endif
 	  return 0;
 	}
     }
@@ -494,6 +500,7 @@ int BV (clib_bihash_search)
 
 u8 *BV (format_bihash_lru) (u8 * s, va_list * args)
 {
+#if BIHASH_KVP_SIZE > 0
   int i;
   BVT (clib_bihash_bucket) * b = va_arg (*args, BVT (clib_bihash_bucket) *);
   u16 cache_lru = b->cache_lru;
@@ -502,13 +509,18 @@ u8 *BV (format_bihash_lru) (u8 * s, va_list * args)
 
   for (i = 0; i < BIHASH_KVP_CACHE_SIZE; i++)
     s = format (s, "[%d] ", ((cache_lru >> (3 * i)) & 7));
+#else
+  return format (s, "cache not configured");
+#endif
   return (s);
 }
 
 void
 BV (clib_bihash_update_lru_not_inline) (BVT (clib_bihash_bucket) * b, u8 slot)
 {
+#if BIHASH_KVP_SIZE > 0
   BV (clib_bihash_update_lru) (b, slot);
+#endif
 }
 
 u8 *BV (format_bihash) (u8 * s, va_list * args)
diff --git a/src/vppinfra/bihash_template.h b/src/vppinfra/bihash_template.h
index 3d9c59cb..ea1b6f7b 100644
--- a/src/vppinfra/bihash_template.h
+++ b/src/vppinfra/bihash_template.h
@@ -65,7 +65,9 @@ typedef struct
     };
     u64 as_u64;
   };
+#if BIHASH_KVP_CACHE_SIZE > 0
     BVT (clib_bihash_kv) cache[BIHASH_KVP_CACHE_SIZE];
+#endif
 } BVT (clib_bihash_bucket);
 
 typedef struct
@@ -155,11 +157,16 @@ BV (clib_bihash_update_lru_not_inline) (BVT (clib_bihash_bucket) * b,
 
 static inline u8 BV (clib_bihash_get_lru) (BVT (clib_bihash_bucket) * b)
 {
+#if BIHASH_KVP_CACHE_SIZE > 0
   return (b->cache_lru >> (3 * (BIHASH_KVP_CACHE_SIZE - 1))) & 7;
+#else
+  return 0;
+#endif
 }
 
 static inline void BV (clib_bihash_reset_cache) (BVT (clib_bihash_bucket) * b)
 {
+#if BIHASH_KVP_CACHE_SIZE > 0
   u16 initial_lru_value;
 
   memset (b->cache, 0xff, sizeof (b->cache));
@@ -180,6 +187,7 @@ static inline void BV (clib_bihash_reset_cache) (BVT (clib_bihash_bucket) * b)
     initial_lru_value = (0 << 12) | (1 << 9) | (2 << 6) | (3 << 3) | (4 << 0);
 
   b->cache_lru = initial_lru_value;
+#endif
 }
 
 static inline int BV (clib_bihash_lock_bucket) (BVT (clib_bihash_bucket) * b)
@@ -254,7 +262,9 @@ static inline int BV (clib_bihash_search_inline)
   u32 bucket_index;
   BVT (clib_bihash_value) * v;
   BVT (clib_bihash_bucket) * b;
+#if BIHASH_KVP_CACHE_SIZE > 0
   BVT (clib_bihash_kv) * kvp;
+#endif
   int i, limit;
 
   hash = BV (clib_bihash_hash) (key_result);
@@ -265,6 +275,7 @@ static inline int BV (clib_bihash_search_inline)
   if (b->offset == 0)
     return -1;
 
+#if BIHASH_KVP_CACHE_SIZE > 0
   /* Check the cache, if not currently locked */
   if (PREDICT_TRUE ((b->cache_lru & (1 << 15)) == 0))
     {
@@ -280,6 +291,7 @@ static inline int BV (clib_bihash_search_inline)
 	    }
 	}
     }
+#endif
 
   hash >>= h->log2_nbuckets;
 
@@ -295,9 +307,10 @@ static inline int BV (clib_bihash_search_inline)
     {
       if (BV (clib_bihash_key_compare) (v->kvp[i].key, key_result->key))
 	{
-	  u8 cache_slot;
 	  *key_result = v->kvp[i];
 
+#if BIHASH_KVP_CACHE_SIZE > 0
+	  u8 cache_slot;
 	  /* Try to lock the bucket */
 	  if (BV (clib_bihash_lock_bucket) (b))
 	    {
@@ -309,6 +322,7 @@ static inline int BV (clib_bihash_search_inline)
 	      BV (clib_bihash_unlock_bucket) (b);
 	      h->cache_misses++;
 	    }
+#endif
 	  return 0;
 	}
     }
@@ -323,7 +337,9 @@ static inline int BV (clib_bihash_search_inline_2)
   u32 bucket_index;
   BVT (clib_bihash_value) * v;
   BVT (clib_bihash_bucket) * b;
+#if BIHASH_KVP_CACHE_SIZE > 0
   BVT (clib_bihash_kv) * kvp;
+#endif
   int i, limit;
 
   ASSERT (valuep);
@@ -337,6 +353,7 @@ static inline int BV (clib_bihash_search_inline_2)
     return -1;
 
   /* Check the cache, if currently unlocked */
+#if BIHASH_KVP_CACHE_SIZE > 0
   if (PREDICT_TRUE ((b->cache_lru & (1 << 15)) == 0))
     {
       limit = BIHASH_KVP_CACHE_SIZE;
@@ -351,6 +368,7 @@ static inline int BV (clib_bihash_search_inline_2)
 	    }
 	}
     }
+#endif
 
   hash >>= h->log2_nbuckets;
   v = BV (clib_bihash_get_value) (h, b->offset);
@@ -365,9 +383,11 @@ static inline int BV (clib_bihash_search_inline_2)
     {
       if (BV (clib_bihash_key_compare) (v->kvp[i].key, search_key->key))
 	{
-	  u8 cache_slot;
 	  *valuep = v->kvp[i];
 
+#if BIHASH_KVP_CACHE_SIZE > 0
+	  u8 cache_slot;
+
 	  /* Try to lock the bucket */
 	  if (BV (clib_bihash_lock_bucket) (b))
 	    {
@@ -379,6 +399,7 @@ static inline int BV (clib_bihash_search_inline_2)
 	      BV (clib_bihash_unlock_bucket) (b);
 	      h->cache_misses++;
 	    }
+#endif
 	  return 0;
 	}
     }