return false;
}
-/* Returns true if the page is within a block suitable for migration to */
-static bool suitable_migration_target(struct page *page)
-{
- /* If the page is a large free page, then disallow migration */
- if (PageBuddy(page)) {
- /*
- * We are checking page_order without zone->lock taken. But
- * the only small danger is that we skip a potentially suitable
- * pageblock, so it's not worth to check order for valid range.
- */
- if (page_order_unsafe(page) >= pageblock_order)
- return false;
- }
-
- /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
- if (migrate_async_suitable(get_pageblock_migratetype(page)))
- return true;
-
- /* Otherwise skip the block */
- return false;
-}
-
/*
* Isolate free pages onto a private freelist. If @strict is true, will abort
* returning 0 on any invalid PFNs or non-free pages inside of the pageblock
#endif /* CONFIG_COMPACTION || CONFIG_CMA */
#ifdef CONFIG_COMPACTION
+
+/* Returns true if the page is within a block suitable for migration to */
+static bool suitable_migration_target(struct page *page)
+{
+ /* If the page is a large free page, then disallow migration */
+ if (PageBuddy(page)) {
+ /*
+ * We are checking page_order without zone->lock taken. But
+ * the only small danger is that we skip a potentially suitable
+ * pageblock, so it's not worth to check order for valid range.
+ */
+ if (page_order_unsafe(page) >= pageblock_order)
+ return false;
+ }
+
+ /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
+ if (migrate_async_suitable(get_pageblock_migratetype(page)))
+ return true;
+
+ /* Otherwise skip the block */
+ return false;
+}
+
/*
* Based on information in the current compact_control, find blocks
* suitable for isolating free pages from and then isolate them.
ISOLATE_SUCCESS, /* Pages isolated, migrate */
} isolate_migrate_t;
+/*
+ * Allow userspace to control policy on scanning the unevictable LRU for
+ * compactable pages.
+ */
+int sysctl_compact_unevictable_allowed __read_mostly = 1;
+
/*
* Isolate all pages that can be migrated from the first suitable block,
* starting at the block pointed to by the migrate scanner pfn within
unsigned long low_pfn, end_pfn;
struct page *page;
const isolate_mode_t isolate_mode =
+ (sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) |
(cc->mode == MIGRATE_ASYNC ? ISOLATE_ASYNC_MIGRATE : 0);
/*
INIT_LIST_HEAD(&cc->freepages);
INIT_LIST_HEAD(&cc->migratepages);
+ /*
+ * When called via /proc/sys/vm/compact_memory
+ * this makes sure we compact the whole zone regardless of
+ * cached scanner positions.
+ */
+ if (cc->order == -1)
+ __reset_isolation_suitable(zone);
+
if (cc->order == -1 || !compaction_deferred(zone, cc->order))
compact_zone(zone, cc);