- * zone_dirtyable_memory - number of dirtyable pages in a zone
- * @zone: the zone
- *
- * Returns the zone's number of pages potentially available for dirty
- * page cache. This is the base value for the per-zone dirty limits.
- */
-static unsigned long zone_dirtyable_memory(struct zone *zone)
-{
- /*
- * The effective global number of dirtyable pages may exclude
- * highmem as a big-picture measure to keep the ratio between
- * dirty memory and lowmem reasonable.
- *
- * But this function is purely about the individual zone and a
- * highmem zone can hold its share of dirty pages, so we don't
- * care about vm_highmem_is_dirtyable here.
- */
- unsigned long nr_pages = zone_page_state(zone, NR_FREE_PAGES) +
- zone_reclaimable_pages(zone);
-
- /* don't allow this to underflow */
- nr_pages -= min(nr_pages, zone->dirty_balance_reserve);
- return nr_pages;
-}
-
-/**