[dgc-xfs:vfs-scale 4/11] lib/dlock-list.c:67:16: error: assigning to 'struct cpumask *' from 'const struct cpumask *' discards qualifiers

[dgc-xfs:vfs-scale 4/11] lib/dlock-list.c:67:16: error: assigning to 'struct cpumask *' from 'const struct cpumask *' discards qualifiers

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs.git vfs-scale
head:   5e5e95a86ea3aa15d83654ec3752451959a689e6
commit: 7a215da6235ea23015452201ae78f1664c27ab8a [4/11] lib/dlock-list: Make sibling CPUs share the same linked list
config: x86_64-buildonly-randconfig-001-20231206 (https://download.01.org/0day-ci/archive/20231206/202312062348.Mq7trSIx-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231206/202312062348.Mq7trSIx-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/202312062348.Mq7trSIx-lkp@intel.com/

All errors (new ones prefixed by >>):

>> lib/dlock-list.c:67:16: error: assigning to 'struct cpumask *' from 'const struct cpumask *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
                   sibling_mask = topology_sibling_cpumask(cpu);
                                ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   1 error generated.


vim +67 lib/dlock-list.c

    36	
    37	/*
    38	 * Initialize cpu2idx mapping table & nr_dlock_lists.
    39	 *
    40	 * It is possible that a dlock-list can be allocated before the cpu2idx is
    41	 * initialized. In this case, all the cpus are mapped to the first entry
    42	 * before initialization.
    43	 *
    44	 * All the sibling CPUs of a sibling group will map to the same dlock list so
    45	 * as to reduce the number of dlock lists to be maintained while minimizing
    46	 * cacheline contention.
    47	 *
    48	 * As the sibling masks are set up in the core initcall phase, this function
    49	 * has to be done in the postcore phase to get the right data.
    50	 */
    51	static int __init cpu2idx_init(void)
    52	{
    53		int idx, cpu;
    54		struct cpumask *sibling_mask;
    55		static struct cpumask mask __initdata;
    56	
    57		cpumask_clear(&mask);
    58		idx = 0;
    59		for_each_possible_cpu(cpu) {
    60			int scpu;
    61	
    62			if (cpumask_test_cpu(cpu, &mask))
    63				continue;
    64			per_cpu(cpu2idx, cpu) = idx;
    65			cpumask_set_cpu(cpu, &mask);
    66	
  > 67			sibling_mask = topology_sibling_cpumask(cpu);
    68			if (sibling_mask) {
    69				for_each_cpu(scpu, sibling_mask) {
    70					per_cpu(cpu2idx, scpu) = idx;
    71					cpumask_set_cpu(scpu, &mask);
    72				}
    73			}
    74			idx++;
    75		}
    76	
    77		/*
    78		 * nr_dlock_lists can only be set after cpu2idx is properly
    79		 * initialized.
    80		 */
    81		smp_mb();
    82		nr_dlock_lists = idx;
    83		WARN_ON(nr_dlock_lists > nr_cpu_ids);
    84	
    85		pr_info("dlock-list: %d head entries per dlock list.\n",
    86			nr_dlock_lists);
    87		return 0;
    88	}
    89	postcore_initcall(cpu2idx_init);
    90	

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