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-rw-r--r--mm/compaction.c56
1 files changed, 44 insertions, 12 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index ad40d67421f3..94b5c0865dd1 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -219,6 +219,20 @@ static void reset_cached_positions(struct zone *zone)
}
/*
+ * Hugetlbfs pages should consistenly be skipped until updated by the hugetlb
+ * subsystem. It is always pointless to compact pages of pageblock_order and
+ * the free scanner can reconsider when no longer huge.
+ */
+static bool pageblock_skip_persistent(struct page *page, unsigned int order)
+{
+ if (!PageHuge(page))
+ return false;
+ if (order != pageblock_order)
+ return false;
+ return true;
+}
+
+/*
* This function is called to clear all cached information on pageblocks that
* should be skipped for page isolation when the migrate and free page scanner
* meet.
@@ -242,6 +256,8 @@ static void __reset_isolation_suitable(struct zone *zone)
continue;
if (zone != page_zone(page))
continue;
+ if (pageblock_skip_persistent(page, compound_order(page)))
+ continue;
clear_pageblock_skip(page);
}
@@ -307,7 +323,13 @@ static inline bool isolation_suitable(struct compact_control *cc,
return true;
}
-static void update_pageblock_skip(struct compact_control *cc,
+static inline bool pageblock_skip_persistent(struct page *page,
+ unsigned int order)
+{
+ return false;
+}
+
+static inline void update_pageblock_skip(struct compact_control *cc,
struct page *page, unsigned long nr_isolated,
bool migrate_scanner)
{
@@ -449,13 +471,15 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
* and the only danger is skipping too much.
*/
if (PageCompound(page)) {
- unsigned int comp_order = compound_order(page);
-
- if (likely(comp_order < MAX_ORDER)) {
- blockpfn += (1UL << comp_order) - 1;
- cursor += (1UL << comp_order) - 1;
+ const unsigned int order = compound_order(page);
+
+ if (pageblock_skip_persistent(page, order)) {
+ set_pageblock_skip(page);
+ blockpfn = end_pfn;
+ } else if (likely(order < MAX_ORDER)) {
+ blockpfn += (1UL << order) - 1;
+ cursor += (1UL << order) - 1;
}
-
goto isolate_fail;
}
@@ -772,11 +796,13 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* danger is skipping too much.
*/
if (PageCompound(page)) {
- unsigned int comp_order = compound_order(page);
-
- if (likely(comp_order < MAX_ORDER))
- low_pfn += (1UL << comp_order) - 1;
+ const unsigned int order = compound_order(page);
+ if (pageblock_skip_persistent(page, order)) {
+ set_pageblock_skip(page);
+ low_pfn = end_pfn;
+ } else if (likely(order < MAX_ORDER))
+ low_pfn += (1UL << order) - 1;
goto isolate_fail;
}
@@ -838,7 +864,13 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* is safe to read and it's 0 for tail pages.
*/
if (unlikely(PageCompound(page))) {
- low_pfn += (1UL << compound_order(page)) - 1;
+ const unsigned int order = compound_order(page);
+
+ if (pageblock_skip_persistent(page, order)) {
+ set_pageblock_skip(page);
+ low_pfn = end_pfn;
+ } else
+ low_pfn += (1UL << order) - 1;
goto isolate_fail;
}
}