tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-percpu-local_lock-v1r10
head:   e1091ede0db3313db25301e58af64ca32864c27d
commit: 6908776bbd1821e6b83b107cd2d8d8339a3c1a31 [11/16] mm/page_alloc: Split per cpu page lists and zone stats
config: m68k-randconfig-r011-20210322 (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git/commit/?id=6908776bbd1821e6b83b107cd2d8d8339a3c1a31
        git remote add mel https://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git
        git fetch --no-tags mel mm-percpu-local_lock-v1r10
        git checkout 6908776bbd1821e6b83b107cd2d8d8339a3c1a31
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k 

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 >>):

   mm/vmstat.c: In function 'zoneinfo_show_print':
>> mm/vmstat.c:1690:28: warning: variable 'pzstats' set but not used [-Wunused-but-set-variable]
    1690 |   struct per_cpu_zonestat *pzstats;
         |                            ^~~~~~~


vim +/pzstats +1690 mm/vmstat.c

  1686	
  1687		seq_printf(m, "\n  pagesets");
  1688		for_each_online_cpu(i) {
  1689			struct per_cpu_pages *pcp;
> 1690			struct per_cpu_zonestat *pzstats;
  1691	
  1692			pcp = per_cpu_ptr(zone->per_cpu_pageset, i);
  1693			pzstats = per_cpu_ptr(zone->per_cpu_zonestats, i);
  1694			seq_printf(m,
  1695				   "\n    cpu: %i"
  1696				   "\n              count: %i"
  1697				   "\n              high:  %i"
  1698				   "\n              batch: %i",
  1699				   i,
  1700				   pcp->count,
  1701				   pcp->high,
  1702				   pcp->batch);
  1703	#ifdef CONFIG_SMP
  1704			seq_printf(m, "\n  vm stats threshold: %d",
  1705					pzstats->stat_threshold);
  1706	#endif
  1707		}
  1708		seq_printf(m,
  1709			   "\n  node_unreclaimable:  %u"
  1710			   "\n  start_pfn:           %lu",
  1711			   pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
  1712			   zone->zone_start_pfn);
  1713		seq_putc(m, '\n');
  1714	}
  1715	

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