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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 17:04:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-22 17:04:18 -0700
commit9e39264ed4f687251632c0a6f4a70c2e51719662 (patch)
tree27651ca028328ac5e7b5a030312ad113b6cb8b2b
parentdc43d9fa73d82083656fb9c02f4823bcdcfb9f91 (diff)
parent1e01979c8f502ac13e3cdece4f38712c5944e6e8 (diff)
Merge branch 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, numa: Implement pfn -> nid mapping granularity check x86, mm: s/PAGES_PER_ELEMENT/PAGES_PER_SECTION/
-rw-r--r--arch/x86/include/asm/mmzone_32.h6
-rw-r--r--arch/x86/mm/numa.c15
-rw-r--r--arch/x86/mm/numa_32.c6
-rw-r--r--include/linux/mm.h1
-rw-r--r--mm/page_alloc.c54
5 files changed, 76 insertions, 6 deletions
diff --git a/arch/x86/include/asm/mmzone_32.h b/arch/x86/include/asm/mmzone_32.h
index ffa037f28d39..55728e121473 100644
--- a/arch/x86/include/asm/mmzone_32.h
+++ b/arch/x86/include/asm/mmzone_32.h
@@ -34,15 +34,15 @@ static inline void resume_map_numa_kva(pgd_t *pgd) {}
* 64Gb / 4096bytes/page = 16777216 pages
*/
#define MAX_NR_PAGES 16777216
-#define MAX_ELEMENTS 1024
-#define PAGES_PER_ELEMENT (MAX_NR_PAGES/MAX_ELEMENTS)
+#define MAX_SECTIONS 1024
+#define PAGES_PER_SECTION (MAX_NR_PAGES/MAX_SECTIONS)
extern s8 physnode_map[];
static inline int pfn_to_nid(unsigned long pfn)
{
#ifdef CONFIG_NUMA
- return((int) physnode_map[(pfn) / PAGES_PER_ELEMENT]);
+ return((int) physnode_map[(pfn) / PAGES_PER_SECTION]);
#else
return 0;
#endif
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index f5510d889a22..fbeaaf416610 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -496,6 +496,7 @@ static bool __init numa_meminfo_cover_memory(const struct numa_meminfo *mi)
static int __init numa_register_memblks(struct numa_meminfo *mi)
{
+ unsigned long uninitialized_var(pfn_align);
int i, nid;
/* Account for nodes with cpus and no memory */
@@ -511,6 +512,20 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
/* for out of order entries */
sort_node_map();
+
+ /*
+ * If sections array is gonna be used for pfn -> nid mapping, check
+ * whether its granularity is fine enough.
+ */
+#ifdef NODE_NOT_IN_PAGE_FLAGS
+ pfn_align = node_map_pfn_alignment();
+ if (pfn_align && pfn_align < PAGES_PER_SECTION) {
+ printk(KERN_WARNING "Node alignment %LuMB < min %LuMB, rejecting NUMA config\n",
+ PFN_PHYS(pfn_align) >> 20,
+ PFN_PHYS(PAGES_PER_SECTION) >> 20);
+ return -EINVAL;
+ }
+#endif
if (!numa_meminfo_cover_memory(mi))
return -EINVAL;
diff --git a/arch/x86/mm/numa_32.c b/arch/x86/mm/numa_32.c
index 849a975d3fa0..3adebe7e536a 100644
--- a/arch/x86/mm/numa_32.c
+++ b/arch/x86/mm/numa_32.c
@@ -41,7 +41,7 @@
* physnode_map[16-31] = 1;
* physnode_map[32- ] = -1;
*/
-s8 physnode_map[MAX_ELEMENTS] __read_mostly = { [0 ... (MAX_ELEMENTS - 1)] = -1};
+s8 physnode_map[MAX_SECTIONS] __read_mostly = { [0 ... (MAX_SECTIONS - 1)] = -1};
EXPORT_SYMBOL(physnode_map);
void memory_present(int nid, unsigned long start, unsigned long end)
@@ -52,8 +52,8 @@ void memory_present(int nid, unsigned long start, unsigned long end)
nid, start, end);
printk(KERN_DEBUG " Setting physnode_map array to node %d for pfns:\n", nid);
printk(KERN_DEBUG " ");
- for (pfn = start; pfn < end; pfn += PAGES_PER_ELEMENT) {
- physnode_map[pfn / PAGES_PER_ELEMENT] = nid;
+ for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
+ physnode_map[pfn / PAGES_PER_SECTION] = nid;
printk(KERN_CONT "%lx ", pfn);
}
printk(KERN_CONT "\n");
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9670f71d7be9..c70a326b8f26 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1313,6 +1313,7 @@ extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn);
extern void remove_all_active_ranges(void);
void sort_node_map(void);
+unsigned long node_map_pfn_alignment(void);
unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
unsigned long end_pfn);
extern unsigned long absent_pages_in_range(unsigned long start_pfn,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4e8985acdab8..9119faae6e6a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4585,6 +4585,60 @@ void __init sort_node_map(void)
cmp_node_active_region, NULL);
}
+/**
+ * node_map_pfn_alignment - determine the maximum internode alignment
+ *
+ * This function should be called after node map is populated and sorted.
+ * It calculates the maximum power of two alignment which can distinguish
+ * all the nodes.
+ *
+ * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
+ * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the
+ * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is
+ * shifted, 1GiB is enough and this function will indicate so.
+ *
+ * This is used to test whether pfn -> nid mapping of the chosen memory
+ * model has fine enough granularity to avoid incorrect mapping for the
+ * populated node map.
+ *
+ * Returns the determined alignment in pfn's. 0 if there is no alignment
+ * requirement (single node).
+ */
+unsigned long __init node_map_pfn_alignment(void)
+{
+ unsigned long accl_mask = 0, last_end = 0;
+ int last_nid = -1;
+ int i;
+
+ for_each_active_range_index_in_nid(i, MAX_NUMNODES) {
+ int nid = early_node_map[i].nid;
+ unsigned long start = early_node_map[i].start_pfn;
+ unsigned long end = early_node_map[i].end_pfn;
+ unsigned long mask;
+
+ if (!start || last_nid < 0 || last_nid == nid) {
+ last_nid = nid;
+ last_end = end;
+ continue;
+ }
+
+ /*
+ * Start with a mask granular enough to pin-point to the
+ * start pfn and tick off bits one-by-one until it becomes
+ * too coarse to separate the current node from the last.
+ */
+ mask = ~((1 << __ffs(start)) - 1);
+ while (mask && last_end <= (start & (mask << 1)))
+ mask <<= 1;
+
+ /* accumulate all internode masks */
+ accl_mask |= mask;
+ }
+
+ /* convert mask to number of pages */
+ return ~accl_mask + 1;
+}
+
/* Find the lowest pfn for a node */
static unsigned long __init find_min_pfn_for_node(int nid)
{