(2013/08/30 22:15), Srivatsa S. Bhat wrote:
Initialize the node's memory-regions structures with the information about
the region-boundaries, at boot time.
Based-on-patch-by: Ankita Garg <gargankita@xxxxxxxxx>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 4 ++++
mm/page_alloc.c | 28 ++++++++++++++++++++++++++++
2 files changed, 32 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f022460..18fdec4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -627,6 +627,10 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
#define LAST_NID_MASK ((1UL << LAST_NID_WIDTH) - 1)
#define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
+/* Hard-code memory region size to be 512 MB for now. */
+#define MEM_REGION_SHIFT (29 - PAGE_SHIFT)
+#define MEM_REGION_SIZE (1UL << MEM_REGION_SHIFT)
+
static inline enum zone_type page_zonenum(const struct page *page)
{
return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b86d7e3..bb2d5d4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4809,6 +4809,33 @@ static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
}
+static void __meminit init_node_memory_regions(struct pglist_data *pgdat)
+{
+ int nid = pgdat->node_id;
+ unsigned long start_pfn = pgdat->node_start_pfn;
+ unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
+ struct node_mem_region *region;
+ unsigned long i, absent;
+ int idx;
+
+ for (i = start_pfn, idx = 0; i < end_pfn;
+ i += region->spanned_pages, idx++) {
+
+ region = &pgdat->node_regions[idx];
It seems that overflow easily occurs.
node_regions[] has 256 entries and MEM_REGION_SIZE is 512MiB. So if
the pgdat has more than 128 GiB, overflow will occur. Am I wrong?
Thanks,
Yasuaki Ishimatsu
+ region->pgdat = pgdat;
+ region->start_pfn = i;
+ region->spanned_pages = min(MEM_REGION_SIZE, end_pfn - i);
+ region->end_pfn = region->start_pfn + region->spanned_pages;
+
+ absent = __absent_pages_in_range(nid, region->start_pfn,
+ region->end_pfn);
+
+ region->present_pages = region->spanned_pages - absent;
+ }
+
+ pgdat->nr_node_regions = idx;
+}
+
void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
unsigned long node_start_pfn, unsigned long *zholes_size)
{
@@ -4837,6 +4864,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
free_area_init_core(pgdat, start_pfn, end_pfn,
zones_size, zholes_size);
+ init_node_memory_regions(pgdat);
}
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
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