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-rw-r--r--mm/memory_hotplug.c42
1 files changed, 35 insertions, 7 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d595606728f9..0eb1a1df649d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -30,6 +30,7 @@
#include <linux/mm_inline.h>
#include <linux/firmware-map.h>
#include <linux/stop_machine.h>
+#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
@@ -1230,10 +1231,12 @@ static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn)
}
/*
- * Scanning pfn is much easier than scanning lru list.
- * Scan pfn from start to end and Find LRU page.
+ * Scan pfn range [start,end) to find movable/migratable pages (LRU pages
+ * and hugepages). We scan pfn because it's much easier than scanning over
+ * linked list. This function returns the pfn of the first found movable
+ * page if it's found, otherwise 0.
*/
-static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
+static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
{
unsigned long pfn;
struct page *page;
@@ -1242,6 +1245,13 @@ static unsigned long scan_lru_pages(unsigned long start, unsigned long end)
page = pfn_to_page(pfn);
if (PageLRU(page))
return pfn;
+ if (PageHuge(page)) {
+ if (is_hugepage_active(page))
+ return pfn;
+ else
+ pfn = round_up(pfn + 1,
+ 1 << compound_order(page)) - 1;
+ }
}
}
return 0;
@@ -1262,6 +1272,19 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (!pfn_valid(pfn))
continue;
page = pfn_to_page(pfn);
+
+ if (PageHuge(page)) {
+ struct page *head = compound_head(page);
+ pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
+ if (compound_order(head) > PFN_SECTION_SHIFT) {
+ ret = -EBUSY;
+ break;
+ }
+ if (isolate_huge_page(page, &source))
+ move_pages -= 1 << compound_order(head);
+ continue;
+ }
+
if (!get_page_unless_zero(page))
continue;
/*
@@ -1294,7 +1317,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
}
if (!list_empty(&source)) {
if (not_managed) {
- putback_lru_pages(&source);
+ putback_movable_pages(&source);
goto out;
}
@@ -1305,7 +1328,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
ret = migrate_pages(&source, alloc_migrate_target, 0,
MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
if (ret)
- putback_lru_pages(&source);
+ putback_movable_pages(&source);
}
out:
return ret;
@@ -1548,8 +1571,8 @@ repeat:
drain_all_pages();
}
- pfn = scan_lru_pages(start_pfn, end_pfn);
- if (pfn) { /* We have page on LRU */
+ pfn = scan_movable_pages(start_pfn, end_pfn);
+ if (pfn) { /* We have movable pages */
ret = do_migrate_range(pfn, end_pfn);
if (!ret) {
drain = 1;
@@ -1568,6 +1591,11 @@ repeat:
yield();
/* drain pcp pages, this is synchronous. */
drain_all_pages();
+ /*
+ * dissolve free hugepages in the memory block before doing offlining
+ * actually in order to make hugetlbfs's object counting consistent.
+ */
+ dissolve_free_huge_pages(start_pfn, end_pfn);
/* check again */
offlined_pages = check_pages_isolated(start_pfn, end_pfn);
if (offlined_pages < 0) {