[PATCH] sparsemem base: teach discontig about sparse ranges
discontig.c has some assumptions that mem_map[]s inside of a node are
contiguous. Teach it to make sure that each region that it's bringing online
is actually made up of valid ranges of ram.
Written-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/mm/discontig.c b/arch/i386/mm/discontig.c
index dcc71f96..088ca47 100644
--- a/arch/i386/mm/discontig.c
+++ b/arch/i386/mm/discontig.c
@@ -216,6 +216,7 @@
{
int nid;
unsigned long size, reserve_pages = 0;
+ unsigned long pfn;
for_each_online_node(nid) {
/*
@@ -234,6 +235,19 @@
size = (size + LARGE_PAGE_BYTES - 1) / LARGE_PAGE_BYTES;
/* now the roundup is correct, convert to PAGE_SIZE pages */
size = size * PTRS_PER_PTE;
+
+ /*
+ * Validate the region we are allocating only contains valid
+ * pages.
+ */
+ for (pfn = node_end_pfn[nid] - size;
+ pfn < node_end_pfn[nid]; pfn++)
+ if (!page_is_ram(pfn))
+ break;
+
+ if (pfn != node_end_pfn[nid])
+ size = 0;
+
printk("Reserving %ld pages of KVA for lmem_map of node %d\n",
size, nid);
node_remap_size[nid] = size;
diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c
index 8766c77..666ca79 100644
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -191,7 +191,7 @@
extern int is_available_memory(efi_memory_desc_t *);
-static inline int page_is_ram(unsigned long pagenr)
+int page_is_ram(unsigned long pagenr)
{
int i;
unsigned long addr, end;
diff --git a/include/asm-i386/page.h b/include/asm-i386/page.h
index 41400d3..8f3dded 100644
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -120,6 +120,8 @@
extern int sysctl_legacy_va_layout;
+extern int page_is_ram(unsigned long pagenr);
+
#endif /* __ASSEMBLY__ */
#ifdef __ASSEMBLY__