Hi hezhongkun,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on c40e8341e3b3bb27e3a65b06b5b454626234c4f0]

url:    https://github.com/intel-lab-lkp/linux/commits/hezhongkun/cgroup-cpuset-Add-a-new-isolated-mems-policy-type/20220904-120436
base:   c40e8341e3b3bb27e3a65b06b5b454626234c4f0
config: x86_64-defconfig
compiler: gcc-11 (Debian 11.3.0-5) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/aafa4e2c9e5c3cd4d02190ac2a7ed0654ed9cf47
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review hezhongkun/cgroup-cpuset-Add-a-new-isolated-mems-policy-type/20220904-120436
        git checkout aafa4e2c9e5c3cd4d02190ac2a7ed0654ed9cf47
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/cgroup/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/cgroup/cpuset.c: In function 'cpuset_mpol_write':
>> kernel/cgroup/cpuset.c:2515:20: warning: unused variable 'cs_allowed' [-Wunused-variable]
    2515 |         nodemask_t cs_allowed;
         |                    ^~~~~~~~~~


vim +/cs_allowed +2515 kernel/cgroup/cpuset.c

  2508	
  2509	/* change cpuset mempolicy */
  2510	static ssize_t cpuset_mpol_write(struct kernfs_open_file *of,
  2511			char *buf, size_t nbytes, loff_t off)
  2512	{
  2513		struct mempolicy *mpol, *old = NULL;
  2514		struct cpuset *cs = css_cs(of_css(of));
> 2515		nodemask_t cs_allowed;
  2516		int err = -ENODEV;
  2517	
  2518		css_get(&cs->css);
  2519		kernfs_break_active_protection(of->kn);
  2520		percpu_down_write(&cpuset_rwsem);
  2521	
  2522		if (!is_cpuset_online(cs))
  2523			goto out_unlock;
  2524	
  2525		buf = strstrip(buf);
  2526		err = mpol_parse_str(buf, &mpol);
  2527	
  2528		if (err) {
  2529			err = -EINVAL;
  2530			goto out_unlock;
  2531		}
  2532	
  2533		spin_lock_irq(&callback_lock);
  2534		old = cs->mempolicy;
  2535		update_cs_mpol_nodemask(cs, mpol);
  2536		cs->mempolicy = mpol;
  2537		spin_unlock_irq(&callback_lock);
  2538	
  2539		update_tasks_cs_mpol(cs);
  2540	
  2541	out_unlock:
  2542		percpu_up_write(&cpuset_rwsem);
  2543		kernfs_unbreak_active_protection(of->kn);
  2544		css_put(&cs->css);
  2545	
  2546		if (old) {
  2547		/*Wait for outstanding programs to complete.*/
  2548			synchronize_rcu();
  2549			mpol_put(old);
  2550		}
  2551		return err ?: nbytes;
  2552	}
  2553	

-- 
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