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: hexagon-randconfig-r045-20220812 (https://download.01.org/0day-ci/archive/20220815/202208151032.dIQzLJma-lkp@intel.com/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 5f1c7e2cc5a3c07cbc2412e851a7283c1841f520)
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/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
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <redacted>

All errors (new ones prefixed by >>):

   In file included from kernel/fork.c:86:

quoted

include/linux/khugepaged.h:53:1: error: non-void function does not return a value [-Werror,-Wreturn-type]

   }
   ^
   kernel/fork.c:163:13: warning: no previous prototype for function 'arch_release_task_struct' [-Wmissing-prototypes]
   void __weak arch_release_task_struct(struct task_struct *tsk)
               ^
   kernel/fork.c:163:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __weak arch_release_task_struct(struct task_struct *tsk)
   ^
   static 
   kernel/fork.c:852:20: warning: no previous prototype for function 'arch_task_cache_init' [-Wmissing-prototypes]
   void __init __weak arch_task_cache_init(void) { }
                      ^
   kernel/fork.c:852:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __init __weak arch_task_cache_init(void) { }
   ^
   static 
   kernel/fork.c:947:12: warning: no previous prototype for function 'arch_dup_task_struct' [-Wmissing-prototypes]
   int __weak arch_dup_task_struct(struct task_struct *dst,
              ^
   kernel/fork.c:947:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int __weak arch_dup_task_struct(struct task_struct *dst,
   ^
   static 
   3 warnings and 1 error generated.
--
   In file included from mm/mmap.c:40:

quoted

include/linux/khugepaged.h:53:1: error: non-void function does not return a value [-Werror,-Wreturn-type]

   }
   ^
   1 error generated.


vim +53 include/linux/khugepaged.h

ba76149f47d8c9 Andrea Arcangeli  2011-01-13  33  
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  34  static inline void khugepaged_exit(struct mm_struct *mm)
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  35  {
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  36  	if (test_bit(MMF_VM_HUGEPAGE, &mm->flags))
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  37  		__khugepaged_exit(mm);
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  38  }
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  39  #else /* CONFIG_TRANSPARENT_HUGEPAGE */
d2081b2bf8195b Yang Shi          2022-05-19  40  static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm)
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  41  {
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  42  }
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  43  static inline void khugepaged_exit(struct mm_struct *mm)
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  44  {
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  45  }
c791576c60288c Yang Shi          2022-05-19  46  static inline void khugepaged_enter_vma(struct vm_area_struct *vma,
6d50e60cd2edb5 David Rientjes    2014-10-29  47  					unsigned long vm_flags)
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  48  {
ba76149f47d8c9 Andrea Arcangeli  2011-01-13  49  }
dff08746d6f7b9 Zach O'Keefe      2022-08-11  50  static inline int collapse_pte_mapped_thp(struct mm_struct *mm,
dff08746d6f7b9 Zach O'Keefe      2022-08-11  51  					  unsigned long addr, bool install_pmd)
27e1f8273113ad Song Liu          2019-09-23  52  {
27e1f8273113ad Song Liu          2019-09-23 @53  }
4aab2be0983031 Vijay Balakrishna 2020-10-10  54  

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