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-rw-r--r--mm/Kconfig9
-rw-r--r--mm/sparse.c38
2 files changed, 41 insertions, 6 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index cd379936cac..fc644c5c065 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -89,3 +89,12 @@ config NEED_MULTIPLE_NODES
config HAVE_MEMORY_PRESENT
def_bool y
depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM
+
+#
+# Architectecture platforms which require a two level mem_section in SPARSEMEM
+# must select this option. This is usually for architecture platforms with
+# an extremely sparse physical address space.
+#
+config ARCH_SPARSEMEM_EXTREME
+ def_bool n
+ depends on SPARSEMEM && 64BIT
diff --git a/mm/sparse.c b/mm/sparse.c
index b54e304df4a..b2b456bf0a5 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -13,7 +13,26 @@
*
* 1) mem_section - memory sections, mem_map's for valid memory
*/
-struct mem_section mem_section[NR_MEM_SECTIONS];
+#ifdef CONFIG_ARCH_SPARSEMEM_EXTREME
+struct mem_section *mem_section[NR_SECTION_ROOTS]
+ ____cacheline_maxaligned_in_smp;
+
+static void sparse_index_init(unsigned long section, int nid)
+{
+ unsigned long root = SECTION_TO_ROOT(section);
+
+ if (mem_section[root])
+ return;
+ mem_section[root] = alloc_bootmem_node(NODE_DATA(nid), PAGE_SIZE);
+ if (mem_section[root])
+ memset(mem_section[root], 0, PAGE_SIZE);
+ else
+ panic("memory_present: NO MEMORY\n");
+}
+#else
+struct mem_section mem_section[NR_MEM_SECTIONS]
+ ____cacheline_maxaligned_in_smp;
+#endif
EXPORT_SYMBOL(mem_section);
/* Record a memory area against a node. */
@@ -24,8 +43,13 @@ void memory_present(int nid, unsigned long start, unsigned long end)
start &= PAGE_SECTION_MASK;
for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
unsigned long section = pfn_to_section_nr(pfn);
- if (!mem_section[section].section_mem_map)
- mem_section[section].section_mem_map = SECTION_MARKED_PRESENT;
+ struct mem_section *ms;
+
+ sparse_index_init(section, nid);
+
+ ms = __nr_to_section(section);
+ if (!ms->section_mem_map)
+ ms->section_mem_map = SECTION_MARKED_PRESENT;
}
}
@@ -85,6 +109,7 @@ static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
{
struct page *map;
int nid = early_pfn_to_nid(section_nr_to_pfn(pnum));
+ struct mem_section *ms = __nr_to_section(pnum);
map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
if (map)
@@ -96,7 +121,7 @@ static struct page *sparse_early_mem_map_alloc(unsigned long pnum)
return map;
printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
- mem_section[pnum].section_mem_map = 0;
+ ms->section_mem_map = 0;
return NULL;
}
@@ -114,8 +139,9 @@ void sparse_init(void)
continue;
map = sparse_early_mem_map_alloc(pnum);
- if (map)
- sparse_init_one_section(&mem_section[pnum], pnum, map);
+ if (!map)
+ continue;
+ sparse_init_one_section(__nr_to_section(pnum), pnum, map);
}
}