6807602: Increase MAX_BUFFER_LEN and MAX_HEAP_BUFFER_LEN on 64-bit Solaris and Linux

Reviewed-by: alanb

src/solaris/native/java/net/net_util_md.h

@@ -111,11 +111,15 @@ extern jint NET_Wait(JNIEnv *env, jint fd, jint flags, jint timeout);
  */
 
 /*
- * Its safe to increase the buffer to 8K, this gives a 5-20%
- * performance boost on volano and overall socket performance.
+ * On 64-bit JDKs we use a much larger stack and heap buffer.
  */
+#ifdef _LP64
+#define MAX_BUFFER_LEN 65536
+#define MAX_HEAP_BUFFER_LEN 131072
+#else
 #define MAX_BUFFER_LEN 8192
 #define MAX_HEAP_BUFFER_LEN 65536
+#endif
 
 #ifdef AF_INET6