Re: [PATCH 12/16] mm: update resctl to use mmap_prepare, mmap_complete, mmap_abort

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

Hi Lorenzo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[cannot apply to brauner-vfs/vfs.all char-misc/char-misc-testing char-misc/char-misc-next char-misc/char-misc-linus s390/features lwn/docs-next linus/master v6.17-rc5 next-20250908]
[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/Lorenzo-Stoakes/mm-shmem-update-shmem-to-use-mmap_prepare/20250908-191516
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/d9e9407d2ee4119c83a704a80763e5344afb42f5.1757329751.git.lorenzo.stoakes%40oracle.com
patch subject: [PATCH 12/16] mm: update resctl to use mmap_prepare, mmap_complete, mmap_abort
config: i386-buildonly-randconfig-001-20250909 (https://download.01.org/0day-ci/archive/20250909/202509091127.USj6agt3-lkp@intel.com/config)
compiler: gcc-13 (Debian 13.3.0-16) 13.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250909/202509091127.USj6agt3-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/202509091127.USj6agt3-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/linux/mm.h:1096,
                    from include/linux/mman.h:6,
                    from fs/resctrl/pseudo_lock.c:19:
   include/linux/huge_mm.h: In function 'split_huge_page_to_list_to_order':
   include/linux/huge_mm.h:591:23: warning: unused variable 'folio' [-Wunused-variable]
     591 |         struct folio *folio = page_folio(page);
         |                       ^~~~~
   include/linux/huge_mm.h: In function 'split_huge_page':
   include/linux/huge_mm.h:598:23: warning: unused variable 'folio' [-Wunused-variable]
     598 |         struct folio *folio = page_folio(page);
         |                       ^~~~~
   fs/resctrl/pseudo_lock.c: In function 'pseudo_lock_dev_mmap_complete':
>> fs/resctrl/pseudo_lock.c:1006:23: warning: variable 'psize' set but not used [-Wunused-but-set-variable]
    1006 |         unsigned long psize;
         |                       ^~~~~


vim +/psize +1006 fs/resctrl/pseudo_lock.c

7168ae330e8105 James Morse     2025-05-15   997  
5ef190013e9b31 Lorenzo Stoakes 2025-09-08   998  static int pseudo_lock_dev_mmap_complete(struct file *filp, struct vm_area_struct *vma,
5ef190013e9b31 Lorenzo Stoakes 2025-09-08   999  					 const void *context)
7168ae330e8105 James Morse     2025-05-15  1000  {
7168ae330e8105 James Morse     2025-05-15  1001  	unsigned long vsize = vma->vm_end - vma->vm_start;
7168ae330e8105 James Morse     2025-05-15  1002  	unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
7168ae330e8105 James Morse     2025-05-15  1003  	struct pseudo_lock_region *plr;
7168ae330e8105 James Morse     2025-05-15  1004  	struct rdtgroup *rdtgrp;
7168ae330e8105 James Morse     2025-05-15  1005  	unsigned long physical;
7168ae330e8105 James Morse     2025-05-15 @1006  	unsigned long psize;
7168ae330e8105 James Morse     2025-05-15  1007  
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1008  	rdtgrp = filp->private_data;
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1009  	plr = rdtgrp->plr;
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1010  
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1011  	physical = __pa(plr->kmem) >> PAGE_SHIFT;
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1012  	psize = plr->size - off;
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1013  
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1014  	memset(plr->kmem + off, 0, vsize);
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1015  
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1016  	if (remap_pfn_range_complete(vma, vma->vm_start, physical + vma->vm_pgoff,
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1017  			    vsize, vma->vm_page_prot)) {
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1018  		mutex_unlock(&rdtgroup_mutex);
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1019  		return -EAGAIN;
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1020  	}
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1021  
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1022  	mutex_unlock(&rdtgroup_mutex);
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1023  	return 0;
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1024  }
5ef190013e9b31 Lorenzo Stoakes 2025-09-08  1025  

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