[PATCH] sparsemem fix for sparse_index_init

[PATCH] sparsemem fix for sparse_index_init

[Bob Picco]

Andrew:

After reviewing recent SPARSEMEM+EXTREME changes for -mm, I spotted a memory 
leak issue.  In sparse_index_init we must evaluate whether the root index is
allocated before allocating, acquiring the lock and then checking
whether the root is already allocated. An alternative would be in the error path
doing a free_bootmem_node but this seems the more expensive method for
boot time.

thanks,

bob

Signed-off-by: Bob Picco <bob.picco@hp.com>


 mm/sparse.c |    3 +++
 1 files changed, 3 insertions(+)

Index: linux-2.6.13-rc6-mm1/mm/sparse.c
===================================================================
--- linux-2.6.13-rc6-mm1.orig/mm/sparse.c	2005-08-19 12:47:53.000000000 -0400
+++ linux-2.6.13-rc6-mm1/mm/sparse.c	2005-08-21 13:36:57.000000000 -0400
@@ -45,6 +45,9 @@ static int sparse_index_init(unsigned lo
 	struct mem_section *section;
 	int ret = 0;
 
+	if (mem_section[root])
+		return -EEXIST;
+
 	section = sparse_index_alloc(nid);
 	/*
 	 * This lock keeps two different sections from