Hi Yi,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on driver-core/driver-core-testing]
[also build test WARNING on linus/master next-20210908]
[cannot apply to cgroup/for-next kees/for-next/pstore v5.14]
[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]

url:    https://github.com/0day-ci/linux/commits/Yi-Tao/support-cgroup-pool-in-v1/20210908-201642
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git 4b93c544e90e2b28326182d31ee008eb80e02074
config: i386-randconfig-s001-20210908 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/6fadbb12de926d6d4fd6d903304d5cbe52bbbc52
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Yi-Tao/support-cgroup-pool-in-v1/20210908-201642
        git checkout 6fadbb12de926d6d4fd6d903304d5cbe52bbbc52
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash kernel/cgroup/

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


sparse warnings: (new ones prefixed by >>)
>> kernel/cgroup/cgroup-v1.c:617:1: sparse: sparse: symbol 'cgroup_pool_mutex' was not declared. Should it be static?
   kernel/cgroup/cgroup-v1.c:490:16: sparse: sparse: context imbalance in '__cgroup1_procs_write' - wrong count at exit
   kernel/cgroup/cgroup-v1.c:991:9: sparse: sparse: context imbalance in 'cgroup1_rename' - different lock contexts for basic block

Please review and possibly fold the followup patch.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org