On 05.08.24 16:59, Kirill A. Shutemov wrote:
The new page type allows physical memory scanners to detect unaccepted
memory and handle it accordingly.
The page type is serialized with zone lock.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
include/linux/page-flags.h | 3 +++
mm/page_alloc.c | 2 ++
2 files changed, 5 insertions(+)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 5769fe6e4950..e19eac9c2b5c 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -943,6 +943,7 @@ enum pagetype {
PG_hugetlb = 0x04000000,
PG_slab = 0x02000000,
PG_zsmalloc = 0x01000000,
+ PG_unaccepted = 0x00800000,
PAGE_TYPE_BASE = 0x80000000,
@@ -1076,6 +1077,8 @@ FOLIO_TEST_FLAG_FALSE(hugetlb)
PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc)
+PAGE_TYPE_OPS(Unaccepted, unaccepted, unaccepted)
I'm sure you're able to come up with some documentation ;)
+
/**
* PageHuge - Determine if the page belongs to hugetlbfs
* @page: The page to test.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 90a1f01d5996..a35efb114496 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6972,6 +6972,7 @@ static bool try_to_accept_memory_one(struct zone *zone)
account_freepages(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
__mod_zone_page_state(zone, NR_UNACCEPTED, -MAX_ORDER_NR_PAGES);
+ __ClearPageUnaccepted(page);
spin_unlock_irqrestore(&zone->lock, flags);
accept_page(page, MAX_PAGE_ORDER);
@@ -7030,6 +7031,7 @@ static bool __free_unaccepted(struct page *page)
list_add_tail(&page->lru, &zone->unaccepted_pages);
account_freepages(zone, MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
__mod_zone_page_state(zone, NR_UNACCEPTED, MAX_ORDER_NR_PAGES);
+ __SetPageUnaccepted(page);
spin_unlock_irqrestore(&zone->lock, flags);
if (first)
At the point PG_unaccepted is set/cleared, we don't have another type
set, right? (IOW, PG_buddy is only set after we cleared PG_unaccepted)
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
--
Cheers,
David / dhildenb
