global_lru_pages() / zone_lru_pages() can be used in two ways:
- to estimate max reclaimable pages in determine_dirtyable_memory() - to calculate the slab scan ratio
When swap is full or not present, the anon lru lists are not reclaimable
and thus won't be scanned. So the anon pages shall not be counted. Also
rename the function names to reflect the new meaning.
It can greatly (and correctly) increase the slab scan rate under high memory
pressure (when most file pages have been reclaimed and swap is full/absent),
thus avoid possible false OOM kills.
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>