linux-kernel - [PATCH 3/8] mm: Introduce PageUnaccepted() page type

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Message-ID: <20240805145940.2911011-4-kirill.shutemov@linux.intel.com>
Date: Mon,  5 Aug 2024 17:59:35 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
	"Borislav Petkov (AMD)" <bp@...en8.de>,
	Mel Gorman <mgorman@...e.de>,
	Vlastimil Babka <vbabka@...e.cz>
Cc: Tom Lendacky <thomas.lendacky@....com>,
	Mike Rapoport <rppt@...nel.org>,
	"Matthew Wilcox (Oracle)" <willy@...radead.org>,
	David Hildenbrand <david@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [PATCH 3/8] mm: Introduce PageUnaccepted() page type

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@...ux.intel.com>
---
 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)
+
 /**
  * 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)
-- 
2.43.0