[gmprice:mempolicy2_mbind2 3/13] mm/mempolicy.c:1965:40: warning: variable 'cur_node' set but not used

[gmprice:mempolicy2_mbind2 3/13] mm/mempolicy.c:1965:40: warning: variable 'cur_node' set but not used

[kernel test robot]

tree:   https://github.com/gmprice/linux mempolicy2_mbind2
head:   5dc13fbba4bf6f4a96d78938d99006aebed9613e
commit: cabe4e50f46d000ff06b4702d62be0c0a51a128c [3/13] mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20240111/202401111048.C45IHXRI-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240111/202401111048.C45IHXRI-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/202401111048.C45IHXRI-lkp@intel.com/

All warnings (new ones prefixed by >>):

   mm/mempolicy.c: In function 'weighted_interleave_nid':
>> mm/mempolicy.c:1965:40: warning: variable 'cur_node' set but not used [-Wunused-but-set-variable]
    1965 |         unsigned int target, nr_nodes, cur_node;
         |                                        ^~~~~~~~
   mm/mempolicy.c: In function 'mpol_parse_str':
   mm/mempolicy.c:3236:26: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
    3236 |                 *--flags = '=';
         |                 ~~~~~~~~~^~~~~
   mm/mempolicy.c:3118:26: note: destination object 'str' of size [0, 9223372036854775807]
    3118 | int mpol_parse_str(char *str, struct mempolicy **mpol)
         |                    ~~~~~~^~~
   mm/mempolicy.c:3236:26: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
    3236 |                 *--flags = '=';
         |                 ~~~~~~~~~^~~~~
   mm/mempolicy.c:3118:26: note: destination object 'str' of size [0, 9223372036854775807]
    3118 | int mpol_parse_str(char *str, struct mempolicy **mpol)
         |                    ~~~~~~^~~
   mm/mempolicy.c:3236:26: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
    3236 |                 *--flags = '=';
         |                 ~~~~~~~~~^~~~~
   mm/mempolicy.c:3118:26: note: destination object 'str' of size [0, 9223372036854775807]
    3118 | int mpol_parse_str(char *str, struct mempolicy **mpol)
         |                    ~~~~~~^~~
   mm/mempolicy.c:3236:26: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
    3236 |                 *--flags = '=';
         |                 ~~~~~~~~~^~~~~
   mm/mempolicy.c:3118:26: note: destination object 'str' of size [0, 9223372036854775807]
    3118 | int mpol_parse_str(char *str, struct mempolicy **mpol)
         |                    ~~~~~~^~~
   mm/mempolicy.c:3236:26: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
    3236 |                 *--flags = '=';
         |                 ~~~~~~~~~^~~~~
   mm/mempolicy.c:3118:26: note: destination object 'str' of size [0, 9223372036854775807]
    3118 | int mpol_parse_str(char *str, struct mempolicy **mpol)
         |                    ~~~~~~^~~
   mm/mempolicy.c:3236:26: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
    3236 |                 *--flags = '=';
         |                 ~~~~~~~~~^~~~~
   mm/mempolicy.c:3118:26: note: destination object 'str' of size [0, 9223372036854775807]
    3118 | int mpol_parse_str(char *str, struct mempolicy **mpol)
         |                    ~~~~~~^~~


vim +/cur_node +1965 mm/mempolicy.c

  1961	
  1962	static unsigned int weighted_interleave_nid(struct mempolicy *pol, pgoff_t ilx)
  1963	{
  1964		nodemask_t nodemask;
> 1965		unsigned int target, nr_nodes, cur_node;
  1966		struct iw_table *table;
  1967		unsigned int weight_total = 0;
  1968		u8 weight;
  1969		int nid;
  1970	
  1971		nr_nodes = read_once_policy_nodemask(pol, &nodemask);
  1972		if (!nr_nodes)
  1973			return numa_node_id();
  1974	
  1975		rcu_read_lock();
  1976		table = rcu_dereference(iw_table);
  1977		/* calculate the total weight */
  1978		for_each_node_mask(nid, nodemask)
  1979			weight_total += table->weights[nid];
  1980	
  1981		/* Calculate the node offset based on totals */
  1982		target = ilx % weight_total;
  1983		nid = first_node(nodemask);
  1984		cur_node = 0;
  1985		while (target) {
  1986			weight = table->weights[nid];
  1987			if (target < weight)
  1988				break;
  1989			target -= weight;
  1990			nid = next_node_in(nid, nodemask);
  1991		}
  1992		rcu_read_unlock();
  1993		return nid;
  1994	}
  1995	

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