sparsemem: ensure we initialise the node mapping for SPARSEMEM_STATIC
Andy Whitcroft [Wed, 22 Aug 2007 21:01:03 +0000 (14:01 -0700)]
Booting SPARSEMEM on NUMA systems trips a BUG in page_alloc.c:

Initializing HighMem for node 0 (00038000:00100000)
Initializing HighMem for node 1 (00100000:001ffe00)
------------[ cut here ]------------
kernel BUG at /home/apw/git/linux-2.6/mm/page_alloc.c:456!
[...]

This occurs because the section to node id mapping is not being
setup correctly during init under SPARSEMEM_STATIC, leading to an
attempt to free pages from all nodes into the zones on node 0.

When the zone_table[] was removed in the following commit, a new
section to node mapping table was introduced:

    commit 89689ae7f95995723fbcd5c116c47933a3bb8b13
    [PATCH] Get rid of zone_table[]

That conversion inadvertantly only initialised the node mapping in
SPARSEMEM_EXTREME.  Ensure we initialise the node mapping in
SPARSEMEM_STATIC.

[akpm@linux-foundation.org: make the stubs static inline]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/sparse.c

index 3047bf0..239f5a7 100644 (file)
@@ -41,6 +41,15 @@ int page_to_nid(struct page *page)
        return section_to_node_table[page_to_section(page)];
 }
 EXPORT_SYMBOL(page_to_nid);
+
+static void set_section_nid(unsigned long section_nr, int nid)
+{
+       section_to_node_table[section_nr] = nid;
+}
+#else /* !NODE_NOT_IN_PAGE_FLAGS */
+static inline void set_section_nid(unsigned long section_nr, int nid)
+{
+}
 #endif
 
 #ifdef CONFIG_SPARSEMEM_EXTREME
@@ -68,10 +77,6 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid)
        struct mem_section *section;
        int ret = 0;
 
-#ifdef NODE_NOT_IN_PAGE_FLAGS
-       section_to_node_table[section_nr] = nid;
-#endif
-
        if (mem_section[root])
                return -EEXIST;
 
@@ -148,6 +153,7 @@ void __init memory_present(int nid, unsigned long start, unsigned long end)
                struct mem_section *ms;
 
                sparse_index_init(section, nid);
+               set_section_nid(section, nid);
 
                ms = __nr_to_section(section);
                if (!ms->section_mem_map)