The patch titled
Subject: mm: add a helper to accept page
has been added to the -mm mm-unstable branch. Its filename is
mm-add-a-helper-to-accept-page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-a-helper-to-accept-page.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mm: add a helper to accept page
Date: Fri, 9 Aug 2024 14:48:52 +0300
Accept a given struct page and add it free list.
The help is useful for physical memory scanners that want to use free
unaccepted memory.
Link: https://lkml.kernel.org/r/20240809114854.3745464-7-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/internal.h | 8 +++++++
mm/page_alloc.c | 47 ++++++++++++++++++++++++++++++++++------------
2 files changed, 43 insertions(+), 12 deletions(-)
--- a/mm/internal.h~mm-add-a-helper-to-accept-page
+++ a/mm/internal.h
@@ -1432,4 +1432,12 @@ unsigned long move_page_tables(struct vm
unsigned long new_addr, unsigned long len,
bool need_rmap_locks, bool for_stack);
+#ifdef CONFIG_UNACCEPTED_MEMORY
+void accept_page(struct page *page);
+#else /* CONFIG_UNACCEPTED_MEMORY */
+static inline void accept_page(struct page *page)
+{
+}
+#endif /* CONFIG_UNACCEPTED_MEMORY */
+
#endif /* __MM_INTERNAL_H */
--- a/mm/page_alloc.c~mm-add-a-helper-to-accept-page
+++ a/mm/page_alloc.c
@@ -6944,27 +6944,18 @@ static bool page_contains_unaccepted(str
return range_contains_unaccepted_memory(start, PAGE_SIZE << order);
}
-static bool try_to_accept_memory_one(struct zone *zone)
+static void __accept_page(struct zone *zone, unsigned long *flags,
+ struct page *page)
{
- unsigned long flags;
- struct page *page;
bool last;
- spin_lock_irqsave(&zone->lock, flags);
- page = list_first_entry_or_null(&zone->unaccepted_pages,
- struct page, lru);
- if (!page) {
- spin_unlock_irqrestore(&zone->lock, flags);
- return false;
- }
-
list_del(&page->lru);
last = list_empty(&zone->unaccepted_pages);
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);
+ spin_unlock_irqrestore(&zone->lock, *flags);
accept_memory(page_to_phys(page), PAGE_SIZE << MAX_PAGE_ORDER);
@@ -6972,6 +6963,38 @@ static bool try_to_accept_memory_one(str
if (last)
static_branch_dec(&zones_with_unaccepted_pages);
+}
+
+void accept_page(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+ unsigned long flags;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ if (!PageUnaccepted(page)) {
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return;
+ }
+
+ /* Unlocks zone->lock */
+ __accept_page(zone, &flags, page);
+}
+
+static bool try_to_accept_memory_one(struct zone *zone)
+{
+ unsigned long flags;
+ struct page *page;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ page = list_first_entry_or_null(&zone->unaccepted_pages,
+ struct page, lru);
+ if (!page) {
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return false;
+ }
+
+ /* Unlocks zone->lock */
+ __accept_page(zone, &flags, page);
return true;
}
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx 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
