kernel/kthread.c:861:13: warning: variable 'ret' set but not used

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   72deda0abee6e705ae71a93f69f55e33be5bca5c
commit: 4d13f4304fa43471bfea101658a11feec7b28ac0 kthread: Implement preferred affinity
date:   3 weeks ago
config: csky-randconfig-r022-20220420 (https://download.01.org/0day-ci/archive/20250130/202501301528.t0cZVbnq-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 12.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250130/202501301528.t0cZVbnq-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/202501301528.t0cZVbnq-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/kthread.c: In function 'kthread_affine_preferred':
>> kernel/kthread.c:861:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
     861 |         int ret;
         |             ^~~


vim +/ret +861 kernel/kthread.c

   855	
   856	int kthread_affine_preferred(struct task_struct *p, const struct cpumask *mask)
   857	{
   858		struct kthread *kthread = to_kthread(p);
   859		cpumask_var_t affinity;
   860		unsigned long flags;
 > 861		int ret;
   862	
   863		if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE) || kthread->started) {
   864			WARN_ON(1);
   865			return -EINVAL;
   866		}
   867	
   868		WARN_ON_ONCE(kthread->preferred_affinity);
   869	
   870		if (!zalloc_cpumask_var(&affinity, GFP_KERNEL))
   871			return -ENOMEM;
   872	
   873		kthread->preferred_affinity = kzalloc(sizeof(struct cpumask), GFP_KERNEL);
   874		if (!kthread->preferred_affinity) {
   875			ret = -ENOMEM;
   876			goto out;
   877		}
   878	
   879		mutex_lock(&kthreads_hotplug_lock);
   880		cpumask_copy(kthread->preferred_affinity, mask);
   881		WARN_ON_ONCE(!list_empty(&kthread->hotplug_node));
   882		list_add_tail(&kthread->hotplug_node, &kthreads_hotplug);
   883		kthread_fetch_affinity(kthread, affinity);
   884	
   885		/* It's safe because the task is inactive. */
   886		raw_spin_lock_irqsave(&p->pi_lock, flags);
   887		do_set_cpus_allowed(p, affinity);
   888		raw_spin_unlock_irqrestore(&p->pi_lock, flags);
   889	
   890		mutex_unlock(&kthreads_hotplug_lock);
   891	out:
   892		free_cpumask_var(affinity);
   893	
   894		return 0;
   895	}
   896	

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