On 26.02.25 15:24, Luiz Capitulino wrote:
On 2025-02-26 09:10, Arnd Bergmann wrote:
On Wed, Feb 26, 2025, at 10:46, kernel test robot wrote:
commit: a2d6e9c1a867bb9f13943cb8483e2ab85b630bcd [5933/6583] mm:
page_ext: add an iteration API for page extensions
config: i386-buildonly-randconfig-004-20250226
In file included from arch/x86/kernel/asm-offsets.c:14:
In file included from include/linux/suspend.h:5:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:21:
In file included from include/linux/mm.h:8:
In file included from include/linux/pgalloc_tag.h:12:
include/linux/page_ext.h:131:20: error: call to undeclared function 'page_to_section'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
131 | iter->start_pfn = page_to_pfn(page);
| ^
include/asm-generic/memory_model.h:64:21: note: expanded from macro
'page_to_pfn'
64 | #define page_to_pfn __page_to_pfn
I'm getting this on all configurations that set CONFIG_SPARSEMEM
but not CONFIG_SPARSEMEM_VMMEMMAP.
Oh, thanks. I didn't build with CONFIG_SPARSEMEM_VMEMMAP=n.
There is also a possible problem with linux/page_ext.h
including pgtable.h and mmzone.h, which I think can lead
to circular header inclusions with linux/mm.h.
Thanks, I'll look into this.
Andrew, I think you'll have to drop this for now. I may not
have the time to look into this this week.
If we feed lookup_page_ext() the PFN instead, and let the caller
of page_ext_iter_begin() deal with the pfn_to_page(), we should be able to
make it work.
<linux/mmzone.h> still needs to be included, but I assume this should be
fine for now.
From a526d3819de7e36a45743d447638b7251881e508 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@xxxxxxxxxx>
Date: Fri, 28 Feb 2025 14:10:15 +0100
Subject: [PATCH] tmp
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
include/linux/page_ext.h | 20 ++++++++++----------
mm/page_ext.c | 14 ++++++--------
2 files changed, 16 insertions(+), 18 deletions(-)
diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index 33a118b31a222..0c4ff10969453 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -2,7 +2,6 @@
#ifndef __LINUX_PAGE_EXT_H
#define __LINUX_PAGE_EXT_H
-#include <linux/pgtable.h>
#include <linux/types.h>
#include <linux/mmzone.h>
#include <linux/stacktrace.h>
@@ -95,7 +94,7 @@ static inline bool page_ext_iter_next_fast_possible(unsigned long next_pfn)
extern struct page_ext *page_ext_get(const struct page *page);
extern void page_ext_put(struct page_ext *page_ext);
-extern struct page_ext *lookup_page_ext(const struct page *page);
+extern struct page_ext *lookup_page_ext(unsigned long pfn);
static inline void *page_ext_data(struct page_ext *page_ext,
struct page_ext_operations *ops)
@@ -119,17 +118,18 @@ struct page_ext_iter {
/**
* page_ext_iter_begin() - Prepare for iterating through page extensions.
* @iter: page extension iterator.
- * @page: The page we're interested in.
+ * @pfn: PFN of the page we're interested in.
*
* Must be called with RCU read lock taken.
*
* Return: NULL if no page_ext exists for this page.
*/
-static inline struct page_ext *page_ext_iter_begin(struct page_ext_iter *iter, struct page *page)
+static inline struct page_ext *page_ext_iter_begin(struct page_ext_iter *iter,
+ unsigned long pfn)
{
iter->index = 0;
- iter->start_pfn = page_to_pfn(page);
- iter->page_ext = lookup_page_ext(page);
+ iter->start_pfn = pfn;
+ iter->page_ext = lookup_page_ext(iter->start_pfn);
return iter->page_ext;
}
@@ -155,7 +155,7 @@ static inline struct page_ext *page_ext_iter_next(struct page_ext_iter *iter)
if (page_ext_iter_next_fast_possible(pfn))
iter->page_ext = page_ext_next(iter->page_ext);
else
- iter->page_ext = lookup_page_ext(pfn_to_page(pfn));
+ iter->page_ext = lookup_page_ext(pfn);
return iter->page_ext;
}
@@ -181,9 +181,9 @@ static inline struct page_ext *page_ext_iter_get(const struct page_ext_iter *ite
*
* IMPORTANT: must be called with RCU read lock taken.
*/
-#define for_each_page_ext(__page, __pgcount, __page_ext, __iter) \
- for (__page_ext = page_ext_iter_begin(&__iter, __page); \
- __page_ext && __iter.index < __pgcount; \
+#define for_each_page_ext(__page, __pgcount, __page_ext, __iter) \
+ for (__page_ext = page_ext_iter_begin(&__iter, page_to_pfn(__page)); \
+ __page_ext && __iter.index < __pgcount; \
__page_ext = page_ext_iter_next(&__iter))
#else /* !CONFIG_PAGE_EXTENSION */
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 23ad30597c05c..19cc0af9c5651 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -165,14 +165,14 @@ void __meminit pgdat_page_ext_init(struct pglist_data *pgdat)
pgdat->node_page_ext = NULL;
}
-struct page_ext *lookup_page_ext(const struct page *page)
+struct page_ext *lookup_page_ext(unsigned long pfn)
{
- unsigned long pfn = page_to_pfn(page);
+ const int nid = page_to_nid(pfn_to_page(pfn));
unsigned long index;
struct page_ext *base;
WARN_ON_ONCE(!rcu_read_lock_held());
- base = NODE_DATA(page_to_nid(page))->node_page_ext;
+ base = NODE_DATA(nid)->node_page_ext;
/*
* The sanity checks the page allocator does upon freeing a
* page can reach here before the page_ext arrays are
@@ -181,8 +181,7 @@ struct page_ext *lookup_page_ext(const struct page *page)
*/
if (unlikely(!base))
return NULL;
- index = pfn - round_down(node_start_pfn(page_to_nid(page)),
- MAX_ORDER_NR_PAGES);
+ index = pfn - round_down(node_start_pfn(nid), MAX_ORDER_NR_PAGES);
return get_entry(base, index);
}
@@ -245,9 +244,8 @@ static bool page_ext_invalid(struct page_ext *page_ext)
return !page_ext || (((unsigned long)page_ext & PAGE_EXT_INVALID) == PAGE_EXT_INVALID);
}
-struct page_ext *lookup_page_ext(const struct page *page)
+struct page_ext *lookup_page_ext(unsigned long pfn)
{
- unsigned long pfn = page_to_pfn(page);
struct mem_section *section = __pfn_to_section(pfn);
struct page_ext *page_ext = READ_ONCE(section->page_ext);
@@ -523,7 +521,7 @@ struct page_ext *page_ext_get(const struct page *page)
struct page_ext *page_ext;
rcu_read_lock();
- page_ext = lookup_page_ext(page);
+ page_ext = lookup_page_ext(page_to_pfn(page));
if (!page_ext) {
rcu_read_unlock();
return NULL;
--
2.48.1
--
Cheers,
David / dhildenb
