Re: mm/page_alloc.c:247:6: warning: unused variable 'nid'

["Kirill A. Shutemov" <kirill@shutemov.name>]

On Sat, Jul 04, 2015 at 05:26:47PM +0800, kbuild test robot wrote:
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   14a6f1989dae9445d4532941bdd6bbad84f4c8da
> commit: 3b242c66ccbd60cf47ab0e8992119d9617548c23 x86: mm: enable deferred struct page initialisation on x86-64
> date:   3 days ago
> config: x86_64-randconfig-x006-201527 (attached as .config)
> reproduce:
>   git checkout 3b242c66ccbd60cf47ab0e8992119d9617548c23
>   # save the attached .config to linux build tree
>   make ARCH=x86_64 
> 
> All warnings (new ones prefixed by >>):
> 
>    mm/page_alloc.c: In function 'early_page_uninitialised':
> >> mm/page_alloc.c:247:6: warning: unused variable 'nid' [-Wunused-variable]
>      int nid = early_pfn_to_nid(pfn);

We can silence the warning with something like patch below. But I'm not
sure it worth it.

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 754c25966a0a..746a6a7b0535 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -911,7 +911,7 @@ extern char numa_zonelist_order[];
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 
 extern struct pglist_data contig_page_data;
-#define NODE_DATA(nid)         (&contig_page_data)
+#define NODE_DATA(nid)         ((void)nid, &contig_page_data)
 #define NODE_MEM_MAP(nid)      mem_map
 
 #else /* CONFIG_NEED_MULTIPLE_NODES */
-- 
 Kirill A. Shutemov

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>