Hi Ming, I love your patch! Perhaps something to improve: [auto build test WARNING on dennis-percpu/for-next] [also build test WARNING on linus/master v6.1 next-20221216] [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/Ming-Lei/lib-percpu-refcount-fix-use-after-free-by-late-release/20221214-105440 base: https://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu.git for-next patch link: https://lore.kernel.org/r/20221214025101.1268437-4-ming.lei%40redhat.com patch subject: [PATCH 3/3] lib/percpu-refcount: drain ->release() in perpcu_ref_exit() config: i386-randconfig-a001 compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/29f8a1f1e11734bdaf885ad8e9bcd614c2087fc0 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Ming-Lei/lib-percpu-refcount-fix-use-after-free-by-late-release/20221214-105440 git checkout 29f8a1f1e11734bdaf885ad8e9bcd614c2087fc0 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=i386 olddefconfig make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): lib/percpu-refcount.c: In function 'percpu_ref_get_switch_waitq': >> lib/percpu-refcount.c:499:20: warning: old-style function definition [-Wold-style-definition] 499 | wait_queue_head_t *percpu_ref_get_switch_waitq() | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +499 lib/percpu-refcount.c 498 > 499 wait_queue_head_t *percpu_ref_get_switch_waitq() -- 0-DAY CI Kernel Test Service https://01.org/lkp