During page isolation, the original migratetype is overwritten, since
MIGRATE_* are enums. Change MIGRATE_ISOLATE to be a standalone bit like
PB_migrate_skip. pageblock bits needs to be word aligned, so expand
the number of pageblock bits from 4 to 8 and make migrate isolate bit 7.
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
include/linux/mmzone.h | 18 +++++++++++++-----
include/linux/page-isolation.h | 2 +-
include/linux/pageblock-flags.h | 33 ++++++++++++++++++++++++++++++++-
mm/page_alloc.c | 21 +++++++++++++++++++--
4 files changed, 65 insertions(+), 9 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8aecbbb0b685..3c7d3f22ccb2 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -106,14 +106,22 @@ static inline bool migratetype_is_mergeable(int mt)
extern int page_group_by_mobility_disabled;
-#define MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1)
+#ifdef CONFIG_MEMORY_ISOLATION
+#define MIGRATETYPE_NO_ISO_MASK (BIT(PB_migratetype_bits) - 1)
+#define MIGRATETYPE_MASK (MIGRATETYPE_NO_ISO_MASK | PB_migrate_isolate_bit)
+#else
+#define MIGRATETYPE_NO_ISO_MASK (BIT(PB_migratetype_bits) - 1)
+#define MIGRATETYPE_MASK (BIT(PB_migratetype_bits) - 1)
+#endif
-#define get_pageblock_migratetype(page) \
- get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)
+#define get_pageblock_migratetype(page) \
+ get_pfnblock_flags_mask(page, page_to_pfn(page), \
+ MIGRATETYPE_MASK)
-#define folio_migratetype(folio) \
- get_pfnblock_flags_mask(&folio->page, folio_pfn(folio), \
+#define folio_migratetype(folio) \
+ get_pfnblock_flags_mask(&folio->page, folio_pfn(folio), \
MIGRATETYPE_MASK)
+
struct free_area {
struct list_head free_list[MIGRATE_TYPES];
unsigned long nr_free;
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index 898bb788243b..51797dc39cbc 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -5,7 +5,7 @@
#ifdef CONFIG_MEMORY_ISOLATION
static inline bool is_migrate_isolate_page(struct page *page)
{
- return get_pageblock_migratetype(page) == MIGRATE_ISOLATE;
+ return get_pageblock_isolate(page);
}
static inline bool is_migrate_isolate(int migratetype)
{
diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
index fc6b9c87cb0a..d6fe17bf0c9b 100644
--- a/include/linux/pageblock-flags.h
+++ b/include/linux/pageblock-flags.h
@@ -20,7 +20,10 @@ enum pageblock_bits {
PB_migrate_end = PB_migrate + PB_migratetype_bits - 1,
/* 3 bits required for migrate types */
PB_migrate_skip,/* If set the block is skipped by compaction */
-
+#ifdef CONFIG_MEMORY_ISOLATION
+ PB_migrate_isolate = 7, /* If set the block is isolated */
+ /* set it to 7 to make pageblock bit word aligned */
+#endif
/*
* Assume the bits will always align on a word. If this assumption
* changes then get/set pageblock needs updating.
@@ -28,6 +31,10 @@ enum pageblock_bits {
NR_PAGEBLOCK_BITS
};
+#ifdef CONFIG_MEMORY_ISOLATION
+#define PB_migrate_isolate_bit BIT(PB_migrate_isolate)
+#endif
+
#if defined(CONFIG_HUGETLB_PAGE)
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
@@ -99,4 +106,28 @@ static inline void set_pageblock_skip(struct page *page)
}
#endif /* CONFIG_COMPACTION */
+#ifdef CONFIG_MEMORY_ISOLATION
+#define get_pageblock_isolate(page) \
+ get_pfnblock_flags_mask(page, page_to_pfn(page), \
+ (1 << (PB_migrate_isolate)))
+#define clear_pageblock_isolate(page) \
+ set_pfnblock_flags_mask(page, 0, page_to_pfn(page), \
+ (1 << PB_migrate_isolate))
+#define set_pageblock_isolate(page) \
+ set_pfnblock_flags_mask(page, (1 << PB_migrate_isolate), \
+ page_to_pfn(page), \
+ (1 << PB_migrate_isolate))
+#else
+static inline bool get_pageblock_isolate(struct page *page)
+{
+ return false;
+}
+static inline void clear_pageblock_isolate(struct page *page)
+{
+}
+static inline void set_pageblock_isolate(struct page *page)
+{
+}
+#endif /* CONFIG_MEMORY_ISOLATION */
+
#endif /* PAGEBLOCK_FLAGS_H */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 16dfcf7ade74..f17f4acc38c6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -362,6 +362,7 @@ unsigned long get_pfnblock_flags_mask(const struct page *page,
unsigned long *bitmap;
unsigned long bitidx, word_bitidx;
unsigned long word;
+ unsigned long flags;
bitmap = get_pageblock_bitmap(page, pfn);
bitidx = pfn_to_bitidx(page, pfn);
@@ -373,7 +374,13 @@ unsigned long get_pfnblock_flags_mask(const struct page *page,
* racy, are not corrupted.
*/
word = READ_ONCE(bitmap[word_bitidx]);
- return (word >> bitidx) & mask;
+ flags = (word >> bitidx) & mask;
+
+#ifdef CONFIG_MEMORY_ISOLATION
+ if (flags & PB_migrate_isolate_bit)
+ return MIGRATE_ISOLATE;
+#endif
+ return flags;
}
static __always_inline int get_pfnblock_migratetype(const struct page *page,
@@ -397,8 +404,18 @@ void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
unsigned long bitidx, word_bitidx;
unsigned long word;
+#ifdef CONFIG_MEMORY_ISOLATION
+ BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 8);
+ /* keep other migratetype bits if MIGRATE_ISOLATE is set */
+ if (flags == MIGRATE_ISOLATE) {
+ mask &= ~((1UL << PB_migratetype_bits) - 1);
+ flags = PB_migrate_isolate_bit;
+ }
+#else
BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
- BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
+#endif
+ /* extra one for MIGRATE_ISOLATE */
+ BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits) + 1);
bitmap = get_pageblock_bitmap(page, pfn);
bitidx = pfn_to_bitidx(page, pfn);
--
2.47.2
