Hi Phil,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tip/sched/core]
[also build test ERROR on linus/master v6.1 next-20221208]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Phil-Auld/Re-sched-debug-CPU-hotplug-operation-suffers-in-a-large-cpu-systems/20221213-031857
patch link:    https://lore.kernel.org/r/Y5d%2BZqdxeJD2eIHL%40lorien.usersys.redhat.com
patch subject: Re: sched/debug: CPU hotplug operation suffers in a large cpu systems
config: arm-randconfig-r046-20221212
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 6e4cea55f0d1104408b26ac574566a0e4de48036)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/intel-lab-lkp/linux/commit/0561e916ce1f2d53558afc8f833031dc0c8cf03b
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Phil-Auld/Re-sched-debug-CPU-hotplug-operation-suffers-in-a-large-cpu-systems/20221213-031857
        git checkout 0561e916ce1f2d53558afc8f833031dc0c8cf03b
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash kernel/

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

All errors (new ones prefixed by >>):

   In file included from kernel/sched/build_utility.c:73:
>> kernel/sched/debug.c:489:15: error: use of undeclared identifier 'sched_domains_mutex'
                   mutex_lock(&sched_domains_mutex);
                               ^
   kernel/sched/debug.c:505:17: error: use of undeclared identifier 'sched_domains_mutex'
                   mutex_unlock(&sched_domains_mutex);
                                 ^
   2 errors generated.


vim +/sched_domains_mutex +489 kernel/sched/debug.c

   478	
   479	static ssize_t sched_verbose_write(struct file *filp, const char __user *ubuf,
   480					   size_t cnt, loff_t *ppos)
   481	{
   482		struct dentry *dentry = filp->f_path.dentry;
   483		bool orig = sched_debug_verbose;
   484		bool bv;
   485		int r;
   486	
   487		r = kstrtobool_from_user(ubuf, cnt, &bv);
   488		if (!r) {
 > 489			mutex_lock(&sched_domains_mutex);
   490			r = debugfs_file_get(dentry);
   491			if (unlikely(r))
   492				return r;
   493			sched_debug_verbose = bv;
   494			debugfs_file_put(dentry);
   495	

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