+ mm-introduce-pageunaccepted-page-type.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: introduce PageUnaccepted() page type
has been added to the -mm mm-unstable branch.  Its filename is
     mm-introduce-pageunaccepted-page-type.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-introduce-pageunaccepted-page-type.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: mm: introduce PageUnaccepted() page type
Date: Fri, 9 Aug 2024 14:48:50 +0300

The new page type allows physical memory scanners to detect unaccepted
memory and handle it accordingly.

The page type is serialized with zone lock.

Link: https://lkml.kernel.org/r/20240809114854.3745464-5-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/page-flags.h |    8 ++++++++
 mm/page_alloc.c            |    2 ++
 2 files changed, 10 insertions(+)

--- a/include/linux/page-flags.h~mm-introduce-pageunaccepted-page-type
+++ a/include/linux/page-flags.h
@@ -939,6 +939,7 @@ enum pagetype {
 	PG_hugetlb	= 0x04000000,
 	PG_slab		= 0x02000000,
 	PG_zsmalloc	= 0x01000000,
+	PG_unaccepted	= 0x00800000,
 
 	PAGE_TYPE_BASE	= 0x80000000,
 
@@ -1072,6 +1073,13 @@ FOLIO_TEST_FLAG_FALSE(hugetlb)
 
 PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc)
 
+/*
+ * Mark pages that has to be accepted before touched for the first time.
+ *
+ * Serialized with zone lock.
+ */
+PAGE_TYPE_OPS(Unaccepted, unaccepted, unaccepted)
+
 /**
  * PageHuge - Determine if the page belongs to hugetlbfs
  * @page: The page to test.
--- a/mm/page_alloc.c~mm-introduce-pageunaccepted-page-type
+++ a/mm/page_alloc.c
@@ -6972,6 +6972,7 @@ static bool try_to_accept_memory_one(str
 
 	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 pag
 	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)
_

Patches currently in -mm which might be from kirill.shutemov@linux.intel.com are

mm-fix-endless-reclaim-on-machines-with-unaccepted-memory.patch
mm-reduce-deferred-struct-page-init-ifdeffery.patch
mm-accept-memory-in-__alloc_pages_bulk.patch
mm-introduce-pageunaccepted-page-type.patch
mm-rework-accept-memory-helpers.patch
mm-add-a-helper-to-accept-page.patch
mm-page_isolation-handle-unaccepted-memory-isolation.patch
mm-accept-to-promo-watermark.patch