Hi Waiman, kernel test robot noticed the following build errors:
[auto build test ERROR on tj-cgroup/for-next] [also build test ERROR on akpm-mm/mm-everything linus/master v6.14 next-20250404] [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/Waiman-Long/mm-vmscan-Skip-memcg-with-usage-in-shrink_node_memcgs/20250406-104208 base: https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git for-next patch link: https://lore.kernel.org/r/20250406024010.1177927-2-longman%40redhat.com patch subject: [PATCH v3 1/2] mm/vmscan: Skip memcg with !usage in shrink_node_memcgs() config: arm-randconfig-001-20250406 (https://download.01.org/0day-ci/archive/20250406/202504061254.dqfqhfm7-...@intel.com/config) compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 92c93f5286b9ff33f27ff694d2dc33da1c07afdd) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250406/202504061254.dqfqhfm7-...@intel.com/reproduce) 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 <l...@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202504061254.dqfqhfm7-...@intel.com/ All errors (new ones prefixed by >>): >> mm/vmscan.c:5929:32: error: incomplete definition of type 'struct mem_cgroup' 5929 | if (!page_counter_read(&memcg->memory)) | ~~~~~^ include/linux/mm_types.h:33:8: note: forward declaration of 'struct mem_cgroup' 33 | struct mem_cgroup; | ^ 1 error generated. vim +5929 mm/vmscan.c 5890 5891 static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc) 5892 { 5893 struct mem_cgroup *target_memcg = sc->target_mem_cgroup; 5894 struct mem_cgroup_reclaim_cookie reclaim = { 5895 .pgdat = pgdat, 5896 }; 5897 struct mem_cgroup_reclaim_cookie *partial = &reclaim; 5898 struct mem_cgroup *memcg; 5899 5900 /* 5901 * In most cases, direct reclaimers can do partial walks 5902 * through the cgroup tree, using an iterator state that 5903 * persists across invocations. This strikes a balance between 5904 * fairness and allocation latency. 5905 * 5906 * For kswapd, reliable forward progress is more important 5907 * than a quick return to idle. Always do full walks. 5908 */ 5909 if (current_is_kswapd() || sc->memcg_full_walk) 5910 partial = NULL; 5911 5912 memcg = mem_cgroup_iter(target_memcg, NULL, partial); 5913 do { 5914 struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat); 5915 unsigned long reclaimed; 5916 unsigned long scanned; 5917 5918 /* 5919 * This loop can become CPU-bound when target memcgs 5920 * aren't eligible for reclaim - either because they 5921 * don't have any reclaimable pages, or because their 5922 * memory is explicitly protected. Avoid soft lockups. 5923 */ 5924 cond_resched(); 5925 5926 mem_cgroup_calculate_protection(target_memcg, memcg); 5927 5928 /* Skip memcg with no usage */ > 5929 if (!page_counter_read(&memcg->memory)) 5930 continue; 5931 5932 if (mem_cgroup_below_min(target_memcg, memcg)) { 5933 /* 5934 * Hard protection. 5935 * If there is no reclaimable memory, OOM. 5936 */ 5937 continue; 5938 } else if (mem_cgroup_below_low(target_memcg, memcg)) { 5939 /* 5940 * Soft protection. 5941 * Respect the protection only as long as 5942 * there is an unprotected supply 5943 * of reclaimable memory from other cgroups. 5944 */ 5945 if (!sc->memcg_low_reclaim) { 5946 sc->memcg_low_skipped = 1; 5947 continue; 5948 } 5949 memcg_memory_event(memcg, MEMCG_LOW); 5950 } 5951 5952 reclaimed = sc->nr_reclaimed; 5953 scanned = sc->nr_scanned; 5954 5955 shrink_lruvec(lruvec, sc); 5956 5957 shrink_slab(sc->gfp_mask, pgdat->node_id, memcg, 5958 sc->priority); 5959 5960 /* Record the group's reclaim efficiency */ 5961 if (!sc->proactive) 5962 vmpressure(sc->gfp_mask, memcg, false, 5963 sc->nr_scanned - scanned, 5964 sc->nr_reclaimed - reclaimed); 5965 5966 /* If partial walks are allowed, bail once goal is reached */ 5967 if (partial && sc->nr_reclaimed >= sc->nr_to_reclaim) { 5968 mem_cgroup_iter_break(target_memcg, memcg); 5969 break; 5970 } 5971 } while ((memcg = mem_cgroup_iter(target_memcg, memcg, partial))); 5972 } 5973 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
