From: Nico Pache <npache@xxxxxxxxxx> Subject: mm/page_alloc.c: fix 'zone_id' may be used uninitialized in this function warning When compiling with -Werror, cc1 will warn that 'zone_id' may be used uninitialized in this function warning. Initialize the zone_id as 0. Its safe to assume that if the code reaches this point it has at least one numa node with memory, so no need for an assertion before init_unavilable_range. Link: https://lkml.kernel.org/r/20210716210336.1114114-1-npache@xxxxxxxxxx Fixes: 122e093c1734 ("mm/page_alloc: fix memory map initialization for descending nodes") Signed-off-by: Nico Pache <npache@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c~fix-zone_id-may-be-used-uninitialized-in-this-function-warning +++ a/mm/page_alloc.c @@ -6715,7 +6715,7 @@ static void __init memmap_init(void) { unsigned long start_pfn, end_pfn; unsigned long hole_pfn = 0; - int i, j, zone_id, nid; + int i, j, zone_id = 0, nid; for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { struct pglist_data *node = NODE_DATA(nid); _