X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fsparse.c;h=347249a4917afa922f4c8ae5d38fbfe81c189a5a;hb=d44ed4f86892e350f4b16a3489b7e7c1a9bb7ead;hp=b2b456bf0a5d03cb10ceb3c3cd63443040a47137;hpb=802f192e4a600f7ef84ca25c8b818c8830acef5a;p=linux-2.6

diff --git a/mm/sparse.c b/mm/sparse.c
index b2b456bf0a..347249a491 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -6,6 +6,7 @@
 #include <linux/mmzone.h>
 #include <linux/bootmem.h>
 #include <linux/module.h>
+#include <linux/spinlock.h>
 #include <asm/dma.h>
 
 /*
@@ -13,27 +14,63 @@
  *
  * 1) mem_section	- memory sections, mem_map's for valid memory
  */
-#ifdef CONFIG_ARCH_SPARSEMEM_EXTREME
+#ifdef CONFIG_SPARSEMEM_EXTREME
 struct mem_section *mem_section[NR_SECTION_ROOTS]
 	____cacheline_maxaligned_in_smp;
+#else
+struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
+	____cacheline_maxaligned_in_smp;
+#endif
+EXPORT_SYMBOL(mem_section);
 
-static void sparse_index_init(unsigned long section, int nid)
+#ifdef CONFIG_SPARSEMEM_EXTREME
+static struct mem_section *sparse_index_alloc(int nid)
 {
-	unsigned long root = SECTION_TO_ROOT(section);
+	struct mem_section *section = NULL;
+	unsigned long array_size = SECTIONS_PER_ROOT *
+				   sizeof(struct mem_section);
+
+	section = alloc_bootmem_node(NODE_DATA(nid), array_size);
+
+	if (section)
+		memset(section, 0, array_size);
+
+	return section;
+}
+
+static int sparse_index_init(unsigned long section_nr, int nid)
+{
+	static spinlock_t index_init_lock = SPIN_LOCK_UNLOCKED;
+	unsigned long root = SECTION_NR_TO_ROOT(section_nr);
+	struct mem_section *section;
+	int ret = 0;
 
 	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");
+		return -EEXIST;
+
+	section = sparse_index_alloc(nid);
+	/*
+	 * This lock keeps two different sections from
+	 * reallocating for the same index
+	 */
+	spin_lock(&index_init_lock);
+
+	if (mem_section[root]) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	mem_section[root] = section;
+out:
+	spin_unlock(&index_init_lock);
+	return ret;
+}
+#else /* !SPARSEMEM_EXTREME */
+static inline int sparse_index_init(unsigned long section_nr, int nid)
+{
+	return 0;
 }
-#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. */
 void memory_present(int nid, unsigned long start, unsigned long end)