- * Cluster size data on cluster size boundary.
- * Input by remapping newly allocated pages to
- * UNIBUS, and taking pages with data already
- * in them.
- *
- * Cpte is the pte of the virtual memory which
- * is mapped to the UNIBUS, and ppte is the pte
- * for the fresh pages. We switch the memory
- * copies of these pte's, to make the allocated
- * virtual memory contain the data (using the old
- * physical pages). We have to rewrite
- * the UNIBUS map so that the newly allocated
- * pages will be used for the next UNIBUS read,
- * and invalidate the kernel translations
- * for the virtual addresses of the pages
- * we are flipping.
- *
- * The idea here is that this is supposed
- * to take less time than copying the data.
+ * Switch pages mapped to UNIBUS with new page p,
+ * as quick form of copy. Remap UNIBUS and invalidate.