only using prefetch on addReplyBulk

src/networking.c

@@ -1070,6 +1070,8 @@ void addReplyBulk(client *c, robj *obj) {
     if (prepareClientToWrite(c) != C_OK) return;
 
     if (sdsEncodedObject(obj)) {
+        /* Prefetch the memory for the `flags` and potential header */
+        redis_prefetch_read((const sds)(obj->ptr) - 1);
         const size_t len = sdslen(obj->ptr);
         _addReplyLongLongBulk(c, len);
         _addReplyToBufferOrList(c,obj->ptr,len);

src/sds.h

@@ -65,23 +65,21 @@ struct __attribute__ ((__packed__)) sdshdr64 {
 #define SDS_HDR_PREFETCH(T, s) redis_prefetch_read((const char *)((s) - sizeof(struct sdshdr##T)))
 
 static inline size_t sdslen(const sds s) {
-    /* Prefetch the memory for the `flags` and potential header */
-    redis_prefetch_read((const char *)(s - 1));
     unsigned char flags = s[-1];
     switch(flags&SDS_TYPE_MASK) {
         case SDS_TYPE_5:
             return SDS_TYPE_5_LEN(flags);
         case SDS_TYPE_8:
-            SDS_HDR_PREFETCH(8,s);
+            // SDS_HDR_PREFETCH(8,s);
             return SDS_HDR(8,s)->len;
         case SDS_TYPE_16:
-            SDS_HDR_PREFETCH(16,s);
+            // SDS_HDR_PREFETCH(16,s);
             return SDS_HDR(16,s)->len;
         case SDS_TYPE_32:
-            SDS_HDR_PREFETCH(32,s);
+            // SDS_HDR_PREFETCH(32,s);
             return SDS_HDR(32,s)->len;
         case SDS_TYPE_64:
-            SDS_HDR_PREFETCH(64,s);
+            // SDS_HDR_PREFETCH(64,s);
             return SDS_HDR(64,s)->len;
     }
     return 0;

src/t_string.c

@@ -309,7 +309,6 @@ int getGenericCommand(client *c) {
     if (checkType(c,o,OBJ_STRING)) {
         return C_ERR;
     }
-
     addReplyBulk(c,o);
     return C_OK;
 }