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From: Pasha Tatashin <pasha.tatashin@soleen.com>
To: pasha.tatashin@soleen.com, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, linux-m68k@lists.linux-m68k.org,
	anshuman.khandual@arm.com, willy@infradead.org,
	akpm@linux-foundation.org, william.kucharski@oracle.com,
	mike.kravetz@oracle.com, vbabka@suse.cz, geert@linux-m68k.org,
	schmitzmic@gmail.com, rostedt@goodmis.org, mingo@redhat.com,
	hannes@cmpxchg.org, guro@fb.com, songmuchun@bytedance.com,
	weixugc@google.com, gthelen@google.com, rientjes@google.com,
	pjt@google.com
Subject: [PATCH v2 5/9] mm: rename init_page_count() -> page_ref_init()
Date: Tue, 21 Dec 2021 15:01:36 +0000	[thread overview]
Message-ID: <20211221150140.988298-6-pasha.tatashin@soleen.com> (raw)
In-Reply-To: <20211221150140.988298-1-pasha.tatashin@soleen.com>

Now, that set_page_count() is not called from outside anymore and about
to be removed, init_page_count() is the only function that is going to
be used to unconditionally set _refcount, however it is restricted to set
it only to 1.

Make init_page_count() aligned with the other page_ref_*
functions by renaming it.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 arch/m68k/mm/motorola.c  |  2 +-
 include/linux/mm.h       |  2 +-
 include/linux/page_ref.h | 10 +++++++---
 mm/page_alloc.c          |  2 +-
 4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index ecbe948f4c1a..dd3b77d03d5c 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -133,7 +133,7 @@ void __init init_pointer_table(void *table, int type)
 
 	/* unreserve the page so it's possible to free that page */
 	__ClearPageReserved(PD_PAGE(dp));
-	init_page_count(PD_PAGE(dp));
+	page_ref_init(PD_PAGE(dp));
 
 	return;
 }
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d211a06784d5..fae3b6ef66a5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2451,7 +2451,7 @@ extern void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
 static inline void free_reserved_page(struct page *page)
 {
 	ClearPageReserved(page);
-	init_page_count(page);
+	page_ref_init(page);
 	__free_page(page);
 	adjust_managed_page_count(page, 1);
 }
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index 03e21ce2f1bd..1af12a0d7ba1 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -107,10 +107,14 @@ static inline void folio_set_count(struct folio *folio, int v)
 }
 
 /*
- * Setup the page count before being freed into the page allocator for
- * the first time (boot or memory hotplug)
+ * Setup the page refcount to one before being freed into the page allocator.
+ * The memory might not be initialized and therefore there cannot be any
+ * assumptions about the current value of page->_refcount. This call should be
+ * done during boot when memory is being initialized, during memory hotplug
+ * when new memory is added, or when a previous reserved memory is unreserved
+ * this is the first time kernel take control of the given memory.
  */
-static inline void init_page_count(struct page *page)
+static inline void page_ref_init(struct page *page)
 {
 	set_page_count(page, 1);
 }
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 13d989d62012..000c057a2d24 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1569,7 +1569,7 @@ static void __meminit __init_single_page(struct page *page, unsigned long pfn,
 {
 	mm_zero_struct_page(page);
 	set_page_links(page, zone, nid, pfn);
-	init_page_count(page);
+	page_ref_init(page);
 	page_mapcount_reset(page);
 	page_cpupid_reset_last(page);
 	page_kasan_tag_reset(page);
-- 
2.34.1.307.g9b7440fafd-goog



  parent reply	other threads:[~2021-12-21 15:02 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-21 15:01 [PATCH v2 0/9] Hardening page _refcount Pasha Tatashin
2021-12-21 15:01 ` [PATCH v2 1/9] mm: add overflow and underflow checks for page->_refcount Pasha Tatashin
2021-12-21 15:01 ` [PATCH v2 2/9] mm: Avoid using set_page_count() in set_page_recounted() Pasha Tatashin
2021-12-21 15:01 ` [PATCH v2 3/9] mm: remove set_page_count() from page_frag_alloc_align Pasha Tatashin
2021-12-21 15:01 ` Pasha Tatashin [this message]
2021-12-21 15:01 ` [PATCH v2 6/9] mm: remove set_page_count() Pasha Tatashin
2021-12-21 15:01 ` [PATCH v2 7/9] mm: simplify page_ref_* functions Pasha Tatashin
2021-12-21 15:01 ` [PATCH v2 8/9] mm: do not use atomic_set_release in page_ref_unfreeze() Pasha Tatashin
2021-12-21 15:01 ` [PATCH v2 9/9] mm: use atomic_cmpxchg_acquire in page_ref_freeze() Pasha Tatashin

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