Re: [PATCH v6 13/15] mm: memory: support clearing page ranges

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

Hi Ankur,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Ankur-Arora/perf-bench-mem-Remove-repetition-around-time-measurement/20250902-161417
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20250902080816.3715913-14-ankur.a.arora%40oracle.com
patch subject: [PATCH v6 13/15] mm: memory: support clearing page ranges
config: i386-randconfig-014-20250903 (https://download.01.org/0day-ci/archive/20250903/202509030344.SZCI0AIf-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250903/202509030344.SZCI0AIf-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/202509030344.SZCI0AIf-lkp@intel.com/

All warnings (new ones prefixed by >>):

   mm/memory.c: In function 'clear_contig_highpages':
   mm/memory.c:7165:38: error: implicit declaration of function 'nth_page'; did you mean 'pte_page'? [-Werror=implicit-function-declaration]
    7165 |                 clear_user_highpages(nth_page(page, i),
         |                                      ^~~~~~~~
         |                                      pte_page
>> mm/memory.c:7165:38: warning: passing argument 1 of 'clear_user_highpages' makes pointer from integer without a cast [-Wint-conversion]
    7165 |                 clear_user_highpages(nth_page(page, i),
         |                                      ^~~~~~~~~~~~~~~~~
         |                                      |
         |                                      int
   In file included from include/linux/bvec.h:10,
                    from include/linux/blk_types.h:10,
                    from include/linux/writeback.h:13,
                    from include/linux/memcontrol.h:23,
                    from include/linux/swap.h:9,
                    from include/linux/mm_inline.h:8,
                    from mm/memory.c:44:
   include/linux/highmem.h:211:54: note: expected 'struct page *' but argument is of type 'int'
     211 | static inline void clear_user_highpages(struct page *page, unsigned long vaddr,
         |                                         ~~~~~~~~~~~~~^~~~
   cc1: some warnings being treated as errors


vim +/clear_user_highpages +7165 mm/memory.c

  7151	
  7152	/*
  7153	 * Clear contiguous pages chunking them up when running under
  7154	 * non-preemptible models.
  7155	 */
  7156	static void clear_contig_highpages(struct page *page, unsigned long addr,
  7157					   unsigned int npages)
  7158	{
  7159		unsigned int i, count, unit;
  7160	
  7161		unit = preempt_model_preemptible() ? npages : PAGE_CONTIG_NR;
  7162	
  7163		for (i = 0; i < npages; ) {
  7164			count = min(unit, npages - i);
> 7165			clear_user_highpages(nth_page(page, i),
  7166					     addr + i * PAGE_SIZE, count);
  7167			i += count;
  7168			cond_resched();
  7169		}
  7170	}
  7171	

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