[127/192] mm/swap: make NODE_DATA an inline function on CONFIG_FLATMEM

Commit Message

Andrew Morton July 1, 2021, 1:53 a.m. UTC

From: Mel Gorman <[e-mail]>
Subject: mm/swap: make NODE_DATA an inline function on CONFIG_FLATMEM

make W=1 generates the following warning in mm/workingset.c for allnoconfig

  mm/workingset.c: In function `unpack_shadow':
  mm/workingset.c:201:15: warning: variable `nid' set but not used [-Wunused-but-set-variable]
    int memcgid, nid;
                 ^~~

On FLATMEM, NODE_DATA returns a global pglist_data without dereferencing
nid.  Make the helper an inline function to suppress the warning, add type
checking and to apply any side-effects in the parameter list.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Mel Gorman <[e-mail]>
Reviewed-by: Yang Shi <[e-mail]>
Acked-by: Vlastimil Babka <[e-mail]>
Cc: Dan Streetman <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 include/linux/mmzone.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Patch

--- a/include/linux/mmzone.h~mm-swap-make-node_data-an-inline-function-on-config_flatmem
+++ a/include/linux/mmzone.h
@@ -1064,7 +1064,10 @@  extern char numa_zonelist_order[];
 #ifndef CONFIG_NUMA
 
 extern struct pglist_data contig_page_data;
-#define NODE_DATA(nid)		(&contig_page_data)
+static inline struct pglist_data *NODE_DATA(int nid)
+{
+	return &contig_page_data;
+}
 #define NODE_MEM_MAP(nid)	mem_map
 
 #else /* CONFIG_NUMA */