Re: [PATCH mm-unstable 3/9] mm/madvise: add file and shmem support to MADV_COLLAPSE

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

Hi Zach,

Thank you for the patch! Yet something to improve:

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

url:    https://github.com/intel-lab-lkp/linux/commits/Zach-O-Keefe/mm-add-file-shmem-support-to-MADV_COLLAPSE/20220812-093122
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220815/202208151331.uxreCJWj-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-3) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/dff08746d6f7b9387b94360b66bd9db644542991
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Zach-O-Keefe/mm-add-file-shmem-support-to-MADV_COLLAPSE/20220812-093122
        git checkout dff08746d6f7b9387b94360b66bd9db644542991
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   mm/khugepaged.c: In function 'set_huge_pmd':
>> mm/khugepaged.c:1403:13: error: assignment of read-only variable 'vmf'
    1403 |         vmf = (struct vm_fault) {
         |             ^


vim +/vmf +1403 mm/khugepaged.c

  1393	
  1394	/* hpage must be locked, and mmap_lock must be held in write */
  1395	static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
  1396				pmd_t *pmdp, struct page *hpage)
  1397	{
  1398		struct vm_fault vmf;
  1399	
  1400		VM_BUG_ON(!PageTransHuge(hpage));
  1401		mmap_assert_write_locked(vma->vm_mm);
  1402	
> 1403		vmf = (struct vm_fault) {
  1404			.vma = vma,
  1405			.address = addr,
  1406			.flags = 0,
  1407			.pmd = pmdp,
  1408		};
  1409	
  1410		if (do_set_pmd(&vmf, hpage))
  1411			return SCAN_FAIL;
  1412	
  1413		get_page(hpage);
  1414		return SCAN_SUCCEED;
  1415	}
  1416	

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