#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. */
#endif
#define ZONE_DMA 0
-#define ZONE_NORMAL 1
-#define ZONE_HIGHMEM 2
+#define ZONE_DMA32 1
+#define ZONE_NORMAL 2
+#define ZONE_HIGHMEM 3
-#define MAX_NR_ZONES 3 /* Sync this with ZONES_SHIFT */
+#define MAX_NR_ZONES 4 /* Sync this with ZONES_SHIFT */
#define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
/*
* On machines where it is needed (eg PCs) we divide physical memory
- * into multiple physical zones. On a PC we have 3 zones:
+ * into multiple physical zones. On a PC we have 4 zones:
*
* ZONE_DMA < 16 MB ISA DMA capable memory
+ * ZONE_DMA32 0 MB Empty
* ZONE_NORMAL 16-896 MB direct mapped by the kernel
* ZONE_HIGHMEM > 896 MB only page cache and user processes
*/
* 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];
/* 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) */
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
#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,
#include <asm/sparsemem.h>
#endif
-#if BITS_PER_LONG == 32 || defined(ARCH_HAS_ATOMIC_UNSIGNED)
+#if BITS_PER_LONG == 32
/*
- * with 32 bit page->flags field, we reserve 8 bits for node/zone info.
- * there are 3 zones (2 bits) and this leaves 8-2=6 bits for nodes.
+ * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
+ * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
*/
-#define FLAGS_RESERVED 8
+#define FLAGS_RESERVED 9
#elif BITS_PER_LONG == 64
/*
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