Re: [PATCH v2 1/1] mm/ksm: recover from memory failure on KSM page by migrating to healthy duplicate

[kernel test robot <lkp@intel.com>]

Hi Longlong,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.18-rc1 next-20251016]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Longlong-Xia/mm-ksm-recover-from-memory-failure-on-KSM-page-by-migrating-to-healthy-duplicate/20251016-182115
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251016101813.484565-2-xialonglong2025%40163.com
patch subject: [PATCH v2 1/1] mm/ksm: recover from memory failure on KSM page by migrating to healthy duplicate
config: x86_64-buildonly-randconfig-003-20251017 (https://download.01.org/0day-ci/archive/20251017/202510171017.wBXHozQb-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251017/202510171017.wBXHozQb-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202510171017.wBXHozQb-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/ksm.c:3160:6: warning: variable 'nid' set but not used [-Wunused-but-set-variable]
    3160 |         int nid;
         |             ^
   1 warning generated.


vim +/nid +3160 mm/ksm.c

  3155	
  3156	static struct page *create_new_stable_node_dup(struct ksm_stable_node *chain_head,
  3157			struct folio *healthy_folio,
  3158			struct ksm_stable_node **new_stable_node)
  3159	{
> 3160		int nid;
  3161		unsigned long kpfn;
  3162		struct page *new_page = NULL;
  3163	
  3164		if (!is_stable_node_chain(chain_head))
  3165			return NULL;
  3166	
  3167		new_page = alloc_page(GFP_HIGHUSER_MOVABLE | __GFP_ZERO);
  3168		if (!new_page)
  3169			return NULL;
  3170	
  3171		copy_highpage(new_page, folio_page(healthy_folio, 0));
  3172	
  3173		*new_stable_node = alloc_stable_node();
  3174		if (!*new_stable_node) {
  3175			__free_page(new_page);
  3176			return NULL;
  3177		}
  3178	
  3179		INIT_HLIST_HEAD(&(*new_stable_node)->hlist);
  3180		kpfn = page_to_pfn(new_page);
  3181		(*new_stable_node)->kpfn = kpfn;
  3182		nid = get_kpfn_nid(kpfn);
  3183		DO_NUMA((*new_stable_node)->nid = nid);
  3184		(*new_stable_node)->rmap_hlist_len = 0;
  3185	
  3186		(*new_stable_node)->head = STABLE_NODE_DUP_HEAD;
  3187		hlist_add_head(&(*new_stable_node)->hlist_dup, &chain_head->hlist);
  3188		ksm_stable_node_dups++;
  3189		folio_set_stable_node(page_folio(new_page), *new_stable_node);
  3190		folio_add_lru(page_folio(new_page));
  3191	
  3192		return new_page;
  3193	}
  3194	

-- 
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https://github.com/intel/lkp-tests/wiki