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-rw-r--r--include/linux/mmzone.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 7519eb4191e..f5fa3082fd6 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -12,6 +12,7 @@
#include <linux/threads.h>
#include <linux/numa.h>
#include <linux/init.h>
+#include <linux/seqlock.h>
#include <asm/atomic.h>
/* Free memory management - zoned buddy allocator. */
@@ -137,6 +138,10 @@ struct zone {
* free areas of different sizes
*/
spinlock_t lock;
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /* see spanned/present_pages for more description */
+ seqlock_t span_seqlock;
+#endif
struct free_area free_area[MAX_ORDER];
@@ -220,6 +225,16 @@ struct zone {
/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
unsigned long zone_start_pfn;
+ /*
+ * zone_start_pfn, spanned_pages and present_pages are all
+ * protected by span_seqlock. It is a seqlock because it has
+ * to be read outside of zone->lock, and it is done in the main
+ * allocator path. But, it is written quite infrequently.
+ *
+ * The lock is declared along with zone->lock because it is
+ * frequently read in proximity to zone->lock. It's good to
+ * give them a chance of being in the same cacheline.
+ */
unsigned long spanned_pages; /* total size, including holes */
unsigned long present_pages; /* amount of memory (excluding holes) */
@@ -273,6 +288,16 @@ typedef struct pglist_data {
struct page *node_mem_map;
#endif
struct bootmem_data *bdata;
+#ifdef CONFIG_MEMORY_HOTPLUG
+ /*
+ * Must be held any time you expect node_start_pfn, node_present_pages
+ * or node_spanned_pages stay constant. Holding this will also
+ * guarantee that any pfn_valid() stays that way.
+ *
+ * Nests above zone->lock and zone->size_seqlock.
+ */
+ spinlock_t node_size_lock;
+#endif
unsigned long node_start_pfn;
unsigned long node_present_pages; /* total number of physical pages */
unsigned long node_spanned_pages; /* total size of physical page
@@ -293,6 +318,8 @@ typedef struct pglist_data {
#endif
#define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
+#include <linux/memory_hotplug.h>
+
extern struct pglist_data *pgdat_list;
void __get_zone_counts(unsigned long *active, unsigned long *inactive,
@@ -509,6 +536,7 @@ static inline struct mem_section *__nr_to_section(unsigned long nr)
return NULL;
return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
}
+extern int __section_nr(struct mem_section* ms);
/*
* We use the lower bits of the mem_map pointer to store