- * This looks at the status of the btr node of the filter. If data is available
- * in the input queue of the filter, or if an error occurred, a minimal timeout
- * for the next select call is requested from the scheduler. Otherwise the
- * scheduler timeout is left unchanged.
+ * If the buffer tree node of the given filter node has data available (or is
+ * in error state) a minimal I/O timeout is requested from the scheduler.
+ * Otherwise the function does nothing.