tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   303392fd5c160822bf778270b28ec5ea50cab2b4
commit: b659baea75469f0c5bd26f18461dfcdc1bbbac82 mm: selftests for exclusive device memory
date:   2 days ago
config: x86_64-randconfig-a006-20210704 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project cb5de7c813f976dd458bd2a7f40702ba648bf650)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b659baea75469f0c5bd26f18461dfcdc1bbbac82
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout b659baea75469f0c5bd26f18461dfcdc1bbbac82
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> lib/test_hmm.c:631:16: warning: variable 'page' set but not used [-Wunused-but-set-variable]
                   struct page *page;
                                ^
   1 warning generated.


vim +/page +631 lib/test_hmm.c

   623	
   624	static int dmirror_check_atomic(struct dmirror *dmirror, unsigned long start,
   625				     unsigned long end)
   626	{
   627		unsigned long pfn;
   628	
   629		for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
   630			void *entry;
 > 631			struct page *page;
   632	
   633			entry = xa_load(&dmirror->pt, pfn);
   634			page = xa_untag_pointer(entry);
   635			if (xa_pointer_tag(entry) == DPT_XA_TAG_ATOMIC)
   636				return -EPERM;
   637		}
   638	
   639		return 0;
   640	}
   641	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org