Hi Liu, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git OLK-6.6 head: 289de29f4f837038aa79e765e64ddc1d410fe5fd commit: a095a940f784db58ea4e87df361f9a4fd0dd977f [2257/2257] memcg: add restrict to swap to cgroup1 config: x86_64-buildonly-randconfig-002-20250520 (https://download.01.org/0day-ci/archive/20250520/202505201603.DayzxkWd-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/20250520/202505201603.DayzxkWd-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/202505201603.DayzxkWd-lkp@intel.com/ All warnings (new ones prefixed by >>):

...

mm/memcontrol.c:4428:12: warning: 'mem_cgroup_check_swap_for_v1' defined but not used [-Wunused-function] 4428 | static int mem_cgroup_check_swap_for_v1(struct folio *folio, swp_entry_t entry) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/mem_cgroup_check_swap_for_v1 +4428 mm/memcontrol.c 4427

4428 static int mem_cgroup_check_swap_for_v1(struct folio *folio, swp_entry_t entry) 4429 { 4430 return 0; 4431 } 4432 #endif 4433

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