-static int read_expire = HZ / 2; /* max time before a read is submitted. */
-static int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
-static int writes_starved = 2; /* max times reads can starve a write */
-static int fifo_batch = 16; /* # of sequential requests treated as one
+static const int read_expire = HZ / 2; /* max time before a read is submitted. */
+static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
+static const int writes_starved = 2; /* max times reads can starve a write */
+static const int fifo_batch = 16; /* # of sequential requests treated as one