Hi Liu, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git OLK-6.6 head: 9809e40d1abbcdf278f3db91f03a94507bdbb442 commit: a095a940f784db58ea4e87df361f9a4fd0dd977f [1455/1455] memcg: add restrict to swap to cgroup1 config: x86_64-buildonly-randconfig-006-20241112 (https://download.01.org/0day-ci/archive/20241203/202412030048.kxkxfpl0-lkp@i...) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241203/202412030048.kxkxfpl0-lkp@i...) 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/202412030048.kxkxfpl0-lkp@intel.com/ All warnings (new ones prefixed by >>):

...

mm/memcontrol.c:4344:5: warning: no previous prototype for 'memcg_swapmax_read' [-Wmissing-prototypes] 4344 | u64 memcg_swapmax_read(struct cgroup_subsys_state *css, struct cftype *cft) | ^~~~~~~~~~~~~~~~~~

vim +/memcg_swapmax_read +4344 mm/memcontrol.c 4343

4344 u64 memcg_swapmax_read(struct cgroup_subsys_state *css, struct cftype *cft) 4345 { 4346 struct mem_cgroup *memcg = mem_cgroup_from_css(css); 4347 4348 if (!static_branch_likely(&memcg_swap_qos_key)) 4349 return PAGE_COUNTER_MAX * PAGE_SIZE; 4350 4351 return READ_ONCE(memcg->swap_dev->max) * PAGE_SIZE; 4352 } 4353

-- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki