Change retry to num times 60. Testing shows that on a known dataset, this has the same growth behavior as 2.4.39, while num times 20 resulted in significant growth.

libraries/liblmdb/mdb.c

@@ -1948,7 +1948,7 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 #else
 	enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
 #endif
-	int rc, retry = num * 20;
+	int rc, retry = num * 60;
 	MDB_txn *txn = mc->mc_txn;
 	MDB_env *env = txn->mt_env;
 	pgno_t pgno, *mop = env->me_pghead;