Encode the type into the bottom four bits of page->private and the
info into the remaining bits. Also turn the bootmem type into a
named enum.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
arch/x86/mm/init_64.c | 9 ++++-----
include/linux/bootmem_info.h | 25 +++++++++++++++++--------
mm/bootmem_info.c | 11 ++++++-----
mm/sparse.c | 8 ++++----
4 files changed, 31 insertions(+), 22 deletions(-)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index d8dbeac8b206..d77f22850aa2 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -983,13 +983,12 @@ int arch_add_memory(int nid, u64 start, u64 size,
static void __meminit free_pagetable(struct page *page, int order)
{
- unsigned long magic;
- unsigned int nr_pages = 1 << order;
-
/* bootmem page has reserved flag */
if (PageReserved(page)) {
- magic = page->index;
- if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
+ enum bootmem_type type = bootmem_type(page);
+ unsigned long nr_pages = 1 << order;
+
+ if (type == SECTION_INFO || type == MIX_SECTION_INFO) {
while (nr_pages--)
put_page_bootmem(page++);
} else
diff --git a/include/linux/bootmem_info.h b/include/linux/bootmem_info.h
index cffa38a73618..e2fe5de93dcc 100644
--- a/include/linux/bootmem_info.h
+++ b/include/linux/bootmem_info.h
@@ -6,11 +6,10 @@
#include <linux/kmemleak.h>
/*
- * Types for free bootmem stored in page->lru.next. These have to be in
- * some random range in unsigned long space for debugging purposes.
+ * Types for free bootmem stored in the low bits of page->private.
*/
-enum {
- MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 12,
+enum bootmem_type {
+ MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 1,
SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE,
MIX_SECTION_INFO,
NODE_INFO,
@@ -21,9 +20,19 @@ enum {
void __init register_page_bootmem_info_node(struct pglist_data *pgdat);
void get_page_bootmem(unsigned long info, struct page *page,
- unsigned long type);
+ enum bootmem_type type);
void put_page_bootmem(struct page *page);
+static inline enum bootmem_type bootmem_type(const struct page *page)
+{
+ return (unsigned long)page->private & 0xf;
+}
+
+static inline unsigned long bootmem_info(const struct page *page)
+{
+ return (unsigned long)page->private >> 4;
+}
+
/*
* Any memory allocated via the memblock allocator and not via the
* buddy will be marked reserved already in the memmap. For those
@@ -31,7 +40,7 @@ void put_page_bootmem(struct page *page);
*/
static inline void free_bootmem_page(struct page *page)
{
- unsigned long magic = page->index;
+ enum bootmem_type type = bootmem_type(page);
/*
* The reserve_bootmem_region sets the reserved flag on bootmem
@@ -39,7 +48,7 @@ static inline void free_bootmem_page(struct page *page)
*/
VM_BUG_ON_PAGE(page_ref_count(page) != 2, page);
- if (magic == SECTION_INFO || magic == MIX_SECTION_INFO)
+ if (type == SECTION_INFO || type == MIX_SECTION_INFO)
put_page_bootmem(page);
else
VM_BUG_ON_PAGE(1, page);
@@ -54,7 +63,7 @@ static inline void put_page_bootmem(struct page *page)
}
static inline void get_page_bootmem(unsigned long info, struct page *page,
- unsigned long type)
+ enum bootmem_type type)
{
}
diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c
index fa7cb0c87c03..95f288169a38 100644
--- a/mm/bootmem_info.c
+++ b/mm/bootmem_info.c
@@ -14,23 +14,24 @@
#include <linux/memory_hotplug.h>
#include <linux/kmemleak.h>
-void get_page_bootmem(unsigned long info, struct page *page, unsigned long type)
+void get_page_bootmem(unsigned long info, struct page *page,
+ enum bootmem_type type)
{
- page->index = type;
+ BUG_ON(type > 0xf);
+ BUG_ON(info > (ULONG_MAX >> 4));
SetPagePrivate(page);
- set_page_private(page, info);
+ set_page_private(page, info << 4 | type);
page_ref_inc(page);
}
void put_page_bootmem(struct page *page)
{
- unsigned long type = page->index;
+ enum bootmem_type type = bootmem_type(page);
BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
if (page_ref_dec_return(page) == 1) {
- page->index = 0;
ClearPagePrivate(page);
set_page_private(page, 0);
INIT_LIST_HEAD(&page->lru);
diff --git a/mm/sparse.c b/mm/sparse.c
index e4b830091d13..ad89ce5d9d28 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -721,19 +721,19 @@ static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
static void free_map_bootmem(struct page *memmap)
{
unsigned long maps_section_nr, removing_section_nr, i;
- unsigned long magic, nr_pages;
+ unsigned long type, nr_pages;
struct page *page = virt_to_page(memmap);
nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
>> PAGE_SHIFT;
for (i = 0; i < nr_pages; i++, page++) {
- magic = page->index;
+ type = bootmem_type(page);
- BUG_ON(magic == NODE_INFO);
+ BUG_ON(type == NODE_INFO);
maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
- removing_section_nr = page_private(page);
+ removing_section_nr = bootmem_info(page);
/*
* When this function is called, the removing section is
--
2.43.0
