[sj:damon/next 76/76] mm/damon/paddr.c:493:3: warning: variable 'applied' is uninitialized when used here

[sj:damon/next 76/76] mm/damon/paddr.c:493:3: warning: variable 'applied' is uninitialized when used here

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git damon/next
head:   25b6468a712e65fa59ad8724e87ed32fb3e1d0c3
commit: 25b6468a712e65fa59ad8724e87ed32fb3e1d0c3 [76/76] mm/damon: add a new DAMOS action for fine-grained filter-aware stat
config: i386-buildonly-randconfig-004-20241207 (https://download.01.org/0day-ci/archive/20241207/202412071433.DgqslKRN-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241207/202412071433.DgqslKRN-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/202412071433.DgqslKRN-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from mm/damon/paddr.c:12:
   In file included from include/linux/pagemap.h:8:
   In file included from include/linux/mm.h:2223:
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   In file included from mm/damon/paddr.c:17:
   include/linux/mm_inline.h:47:41: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
      47 |         __mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
         |                                    ~~~~~~~~~~~ ^ ~~~
   include/linux/mm_inline.h:49:22: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
      49 |                                 NR_ZONE_LRU_BASE + lru, nr_pages);
         |                                 ~~~~~~~~~~~~~~~~ ^ ~~~
>> mm/damon/paddr.c:493:3: warning: variable 'applied' is uninitialized when used here [-Wuninitialized]
     493 |                 applied += folio_size(folio);
         |                 ^~~~~~~
   mm/damon/paddr.c:482:29: note: initialize the variable 'applied' to silence this warning
     482 |         unsigned long addr, applied;
         |                                    ^
         |                                     = 0
   4 warnings generated.


vim +/applied +493 mm/damon/paddr.c

   479	
   480	static unsigned long damon_pa_stat2(struct damon_region *r, struct damos *s)
   481	{
   482		unsigned long addr, applied;
   483		LIST_HEAD(folio_list);
   484	
   485		for (addr = r->ar.start; addr < r->ar.end; addr += PAGE_SIZE) {
   486			struct folio *folio = damon_get_folio(PHYS_PFN(addr));
   487	
   488			if (!folio)
   489				continue;
   490	
   491			if (damos_pa_filter_out(s, folio))
   492				goto put_folio;
 > 493			applied += folio_size(folio);
   494	put_folio:
   495			folio_put(folio);
   496		}
   497		return applied;
   498	}
   499	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [sj:damon/next 76/76] mm/damon/paddr.c:493:3: warning: variable 'applied' is uninitialized when used here

[SeongJae Park]

On Mon, 9 Dec 2024 12:10:42 +0800 kernel test robot <lkp@intel.com> wrote:

> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git damon/next
> head:   25b6468a712e65fa59ad8724e87ed32fb3e1d0c3
> commit: 25b6468a712e65fa59ad8724e87ed32fb3e1d0c3 [76/76] mm/damon: add a new DAMOS action for fine-grained filter-aware stat
> config: i386-buildonly-randconfig-004-20241207 (https://download.01.org/0day-ci/archive/20241207/202412071433.DgqslKRN-lkp@intel.com/config)
> compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241207/202412071433.DgqslKRN-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/202412071433.DgqslKRN-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from mm/damon/paddr.c:12:
>    In file included from include/linux/pagemap.h:8:
>    In file included from include/linux/mm.h:2223:
>    include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
>      518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
>          |                               ~~~~~~~~~~~ ^ ~~~
>    In file included from mm/damon/paddr.c:17:
>    include/linux/mm_inline.h:47:41: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
>       47 |         __mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
>          |                                    ~~~~~~~~~~~ ^ ~~~
>    include/linux/mm_inline.h:49:22: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
>       49 |                                 NR_ZONE_LRU_BASE + lru, nr_pages);
>          |                                 ~~~~~~~~~~~~~~~~ ^ ~~~
> >> mm/damon/paddr.c:493:3: warning: variable 'applied' is uninitialized when used here [-Wuninitialized]
>      493 |                 applied += folio_size(folio);
>          |                 ^~~~~~~
>    mm/damon/paddr.c:482:29: note: initialize the variable 'applied' to silence this warning
>      482 |         unsigned long addr, applied;
>          |                                    ^
>          |                                     = 0
>    4 warnings generated.

Thank you for this kind report!  Just pushed a fix:
https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git/commit/?h=damon/next&id=48b4e032de1655313ff3cdf08d36bd6633993f93


Thanks,
SJ

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