mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nid

[linux-2.6-block.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c2ee4ecad083f897d9ce181492502f48645e0bc3..ffdb2308848d495fecaa375821f9eac92dad3e4a 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4551,39 +4551,41 @@ int __meminit init_currently_empty_zone(struct zone *zone,
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+
 /*
  * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
  */
-int __meminit __early_pfn_to_nid(unsigned long pfn)
+int __meminit __early_pfn_to_nid(unsigned long pfn,
+                                       struct mminit_pfnnid_cache *state)
 {
        unsigned long start_pfn, end_pfn;
        int nid;
-       /*
-        * NOTE: The following SMP-unsafe globals are only used early in boot
-        * when the kernel is running single-threaded.
-        */
-       static unsigned long __meminitdata last_start_pfn, last_end_pfn;
-       static int __meminitdata last_nid;
 
-       if (last_start_pfn <= pfn && pfn < last_end_pfn)
-               return last_nid;
+       if (state->last_start <= pfn && pfn < state->last_end)
+               return state->last_nid;
 
        nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
        if (nid != -1) {
-               last_start_pfn = start_pfn;
-               last_end_pfn = end_pfn;
-               last_nid = nid;
+               state->last_start = start_pfn;
+               state->last_end = end_pfn;
+               state->last_nid = nid;
        }
 
        return nid;
 }
 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
 
+static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
+
+/* Only safe to use early in boot when initialisation is single-threaded */
 int __meminit early_pfn_to_nid(unsigned long pfn)
 {
        int nid;
 
-       nid = __early_pfn_to_nid(pfn);
+       /* The system will behave unpredictably otherwise */
+       BUG_ON(system_state != SYSTEM_BOOTING);
+
+       nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache);
        if (nid >= 0)
                return nid;
        /* just returns 0 */
@@ -4591,15 +4593,23 @@ int __meminit early_pfn_to_nid(unsigned long pfn)
 }
 
 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
-bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node,
+                                       struct mminit_pfnnid_cache *state)
 {
        int nid;
 
-       nid = __early_pfn_to_nid(pfn);
+       nid = __early_pfn_to_nid(pfn, state);
        if (nid >= 0 && nid != node)
                return false;
        return true;
 }
+
+/* Only safe to use early in boot when initialisation is single-threaded */
+bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
+{
+       return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache);
+}
+
 #endif
 
 /**