Memory regions are created at boot up time, from the information obtained
from the firmware. This patchset was developed on ARM platform, on which at
present u-boot bootloader does not export information about memory units that
can be independently power managed. For the purpose of demonstration, 2 hard
coded memory regions are created, of 256MB each on the Panda board with 512MB
RAM.
Signed-off-by: Ankita Garg <ankita@xxxxxxxxxx>
---
include/linux/mmzone.h | 8 +++-----
mm/page_alloc.c | 29 +++++++++++++++++++++++++++++
2 files changed, 32 insertions(+), 5 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bc3e3fd..5dbe1e1 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -627,14 +627,12 @@ typedef struct mem_region_list_data {
*/
struct bootmem_data;
typedef struct pglist_data {
-/* The linkage to node_zones is now removed. The new hierarchy introduced
- * is pg_data_t -> mem_region -> zones
- * struct zone node_zones[MAX_NR_ZONES];
- */
struct zonelist node_zonelists[MAX_ZONELISTS];
int nr_zones;
#ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
- struct page *node_mem_map;
+ strs pg_data_t -> mem_region -> zones
+ * struct zone node_zones[MAX_NR_ZONES];
+ */uct page *node_mem_map;
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
struct page_cgroup *node_page_cgroup;
#endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index da8b045..3d994e8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4285,6 +4285,34 @@ static inline int pageblock_default_order(unsigned int order)
#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
+#define REGIONS_SIZE (512 << 20) >> PAGE_SHIFT
+
+static void init_node_memory_regions(struct pglist_data *pgdat)
+{
+ int cnt = 0;
+ unsigned long i;
+ unsigned long start_pfn = pgdat->node_start_pfn;
+ unsigned long spanned_pages = pgdat->node_spanned_pages;
+ unsigned long total = 0;
+
+ for (i = start_pfn; i < start_pfn + spanned_pages; i+= REGIONS_SIZE) {
+ mem_region_t *mem_region = &pgdat->mem_regions[cnt];
+
+ mem_region->start_pfn = i;
+ if ((spanned_pages - total) <= REGIONS_SIZE) {
+ mem_region->spanned_pages = spanned_pages - total;
+ }
+ else
+ mem_region->spanned_pages = REGIONS_SIZE;
+
+ mem_region->node = pgdat->node_id;
+ mem_region->region = cnt;
+ pgdat->nr_mem_regions++;
+ total += mem_region->spanned_pages;
+ cnt++;
+ }
+}
+
/*
* Set up the zone data structures:
* - mark all pages reserved
@@ -4447,6 +4475,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
(unsigned long)pgdat->node_mem_map);
#endif
+ init_node_memory_regions(pgdat);
free_area_init_core(pgdat, zones_size, zholes_size);
}
--
1.7.4
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