Re: [PATCH v2 7/9] mm/swap: avoid a duplicated swap cache lookup for SWP_SYNCHRONOUS_IO

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

Hi Kairui,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on next-20240103]
[cannot apply to linus/master v6.7-rc8]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Kairui-Song/mm-swapfile-c-add-back-some-comment/20240103-015650
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20240102175338.62012-8-ryncsn%40gmail.com
patch subject: [PATCH v2 7/9] mm/swap: avoid a duplicated swap cache lookup for SWP_SYNCHRONOUS_IO
config: arc-vdk_hs38_smp_defconfig (https://download.01.org/0day-ci/archive/20240103/202401032010.yrIDf885-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240103/202401032010.yrIDf885-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/202401032010.yrIDf885-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/swap_state.c:884: warning: Function parameter or member 'shadow' not described in 'swapin_direct'


vim +884 mm/swap_state.c

d9bfcfdc41e8e5 Huang Ying  2017-09-06  872  
b16a5db0ccd159 Kairui Song 2024-01-03  873  /**
b16a5db0ccd159 Kairui Song 2024-01-03  874   * swapin_direct - swap in folios skipping swap cache and readahead
b16a5db0ccd159 Kairui Song 2024-01-03  875   * @entry: swap entry of this memory
b16a5db0ccd159 Kairui Song 2024-01-03  876   * @gfp_mask: memory allocation flags
b16a5db0ccd159 Kairui Song 2024-01-03  877   * @vmf: fault information
b16a5db0ccd159 Kairui Song 2024-01-03  878   *
b16a5db0ccd159 Kairui Song 2024-01-03  879   * Returns the struct folio for entry and addr after the swap entry is read
b16a5db0ccd159 Kairui Song 2024-01-03  880   * in.
b16a5db0ccd159 Kairui Song 2024-01-03  881   */
983c0b807f7eda Kairui Song 2024-01-03  882  static struct folio *swapin_direct(swp_entry_t entry, gfp_t gfp_mask,
cd81b9fd3de376 Kairui Song 2024-01-03  883  				  struct vm_fault *vmf, void *shadow)
b16a5db0ccd159 Kairui Song 2024-01-03 @884  {
b16a5db0ccd159 Kairui Song 2024-01-03  885  	struct vm_area_struct *vma = vmf->vma;
b16a5db0ccd159 Kairui Song 2024-01-03  886  	struct folio *folio;
b16a5db0ccd159 Kairui Song 2024-01-03  887  
b16a5db0ccd159 Kairui Song 2024-01-03  888  	/* skip swapcache */
b16a5db0ccd159 Kairui Song 2024-01-03  889  	folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0,
b16a5db0ccd159 Kairui Song 2024-01-03  890  				vma, vmf->address, false);
b16a5db0ccd159 Kairui Song 2024-01-03  891  	if (folio) {
9e22e4254bdb8c Kairui Song 2024-01-03  892  		if (mem_cgroup_swapin_charge_folio(folio, NULL,
64ae20cbed3891 Kairui Song 2024-01-03  893  						   GFP_KERNEL, entry)) {
b16a5db0ccd159 Kairui Song 2024-01-03  894  			folio_put(folio);
b16a5db0ccd159 Kairui Song 2024-01-03  895  			return NULL;
b16a5db0ccd159 Kairui Song 2024-01-03  896  		}
64ae20cbed3891 Kairui Song 2024-01-03  897  
64ae20cbed3891 Kairui Song 2024-01-03  898  		__folio_set_locked(folio);
64ae20cbed3891 Kairui Song 2024-01-03  899  		__folio_set_swapbacked(folio);
64ae20cbed3891 Kairui Song 2024-01-03  900  
b16a5db0ccd159 Kairui Song 2024-01-03  901  		mem_cgroup_swapin_uncharge_swap(entry);
b16a5db0ccd159 Kairui Song 2024-01-03  902  
b16a5db0ccd159 Kairui Song 2024-01-03  903  		if (shadow)
b16a5db0ccd159 Kairui Song 2024-01-03  904  			workingset_refault(folio, shadow);
b16a5db0ccd159 Kairui Song 2024-01-03  905  
b16a5db0ccd159 Kairui Song 2024-01-03  906  		folio_add_lru(folio);
b16a5db0ccd159 Kairui Song 2024-01-03  907  
b16a5db0ccd159 Kairui Song 2024-01-03  908  		/* To provide entry to swap_read_folio() */
b16a5db0ccd159 Kairui Song 2024-01-03  909  		folio->swap = entry;
b16a5db0ccd159 Kairui Song 2024-01-03  910  		swap_read_folio(folio, true, NULL);
b16a5db0ccd159 Kairui Song 2024-01-03  911  		folio->private = NULL;
b16a5db0ccd159 Kairui Song 2024-01-03  912  	}
b16a5db0ccd159 Kairui Song 2024-01-03  913  
b16a5db0ccd159 Kairui Song 2024-01-03  914  	return folio;
b16a5db0ccd159 Kairui Song 2024-01-03  915  }
b16a5db0ccd159 Kairui Song 2024-01-03  916  

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