mm: page_alloc: generalize the dirty balance reserve
The dirty balance reserve that dirty throttling has to consider is
merely memory not available to userspace allocations. There is nothing
writeback-specific about it. Generalize the name so that it's reusable
outside of that context.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index d15d88c..6fe7d15 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -278,7 +278,12 @@
unsigned long nr_pages;
nr_pages = zone_page_state(zone, NR_FREE_PAGES);
- nr_pages -= min(nr_pages, zone->dirty_balance_reserve);
+ /*
+ * Pages reserved for the kernel should not be considered
+ * dirtyable, to prevent a situation where reclaim has to
+ * clean pages in order to balance the zones.
+ */
+ nr_pages -= min(nr_pages, zone->totalreserve_pages);
nr_pages += zone_page_state(zone, NR_INACTIVE_FILE);
nr_pages += zone_page_state(zone, NR_ACTIVE_FILE);
@@ -332,7 +337,12 @@
unsigned long x;
x = global_page_state(NR_FREE_PAGES);
- x -= min(x, dirty_balance_reserve);
+ /*
+ * Pages reserved for the kernel should not be considered
+ * dirtyable, to prevent a situation where reclaim has to
+ * clean pages in order to balance the zones.
+ */
+ x -= min(x, totalreserve_pages);
x += global_page_state(NR_INACTIVE_FILE);
x += global_page_state(NR_ACTIVE_FILE);