Re: [PATCH] mm/vmstat: add event for ksm swapping in copy

[kernel test robot <lkp@xxxxxxxxx>]

Hi,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on hnaz-mm/master]

url:    https://github.com/0day-ci/linux/commits/cgel-zte-gmail-com/mm-vmstat-add-event-for-ksm-swapping-in-copy/20220112-195303
base:   https://github.com/hnaz/linux-mm master
config: alpha-buildonly-randconfig-r004-20220112 (https://download.01.org/0day-ci/archive/20220112/202201122306.EC6LSwot-lkp@xxxxxxxxx/config)
compiler: alpha-linux-gcc (GCC) 11.2.0
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://github.com/0day-ci/linux/commit/56a4520e557228d8383f27b6aef54b2f931a0588
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review cgel-zte-gmail-com/mm-vmstat-add-event-for-ksm-swapping-in-copy/20220112-195303
        git checkout 56a4520e557228d8383f27b6aef54b2f931a0588
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=alpha SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   mm/ksm.c: In function 'ksm_might_need_to_copy':
>> mm/ksm.c:2597:32: error: 'KSM_SWPIN_COPY' undeclared (first use in this function)
    2597 |                 count_vm_event(KSM_SWPIN_COPY);
         |                                ^~~~~~~~~~~~~~
   mm/ksm.c:2597:32: note: each undeclared identifier is reported only once for each function it appears in


vim +/KSM_SWPIN_COPY +2597 mm/ksm.c

  2565	
  2566	struct page *ksm_might_need_to_copy(struct page *page,
  2567				struct vm_area_struct *vma, unsigned long address)
  2568	{
  2569		struct anon_vma *anon_vma = page_anon_vma(page);
  2570		struct page *new_page;
  2571	
  2572		if (PageKsm(page)) {
  2573			if (page_stable_node(page) &&
  2574			    !(ksm_run & KSM_RUN_UNMERGE))
  2575				return page;	/* no need to copy it */
  2576		} else if (!anon_vma) {
  2577			return page;		/* no need to copy it */
  2578		} else if (anon_vma->root == vma->anon_vma->root &&
  2579			 page->index == linear_page_index(vma, address)) {
  2580			return page;		/* still no need to copy it */
  2581		}
  2582		if (!PageUptodate(page))
  2583			return page;		/* let do_swap_page report the error */
  2584	
  2585		new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
  2586		if (new_page &&
  2587		    mem_cgroup_charge(page_folio(new_page), vma->vm_mm, GFP_KERNEL)) {
  2588			put_page(new_page);
  2589			new_page = NULL;
  2590		}
  2591		if (new_page) {
  2592			copy_user_highpage(new_page, page, address, vma);
  2593	
  2594			SetPageDirty(new_page);
  2595			__SetPageUptodate(new_page);
  2596			__SetPageLocked(new_page);
> 2597			count_vm_event(KSM_SWPIN_COPY);
  2598		}
  2599	
  2600		return new_page;
  2601	}
  2602	

---
0-DAY CI Kernel Test Service, Intel Corporation
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