Hi Yonghong, kernel test robot noticed the following build warnings: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Yonghong-Song/bpf-Avoid-unnecessary-extra-percpu-memory-allocation/20231216-103310 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20231216023015.3741144-1-yonghong.song%40linux.dev patch subject: [PATCH bpf-next v3 2/6] bpf: Allow per unit prefill for non-fix-size percpu memory allocator config: x86_64-randconfig-003-20231216 (https://download.01.org/0day-ci/archive/20231216/202312162351.UuoFmjJk-lkp@xxxxxxxxx/config) compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231216/202312162351.UuoFmjJk-lkp@xxxxxxxxx/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 <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202312162351.UuoFmjJk-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> kernel/bpf/memalloc.c:665:14: warning: variable 'objcg' is uninitialized when used here [-Wuninitialized] c->objcg = objcg; ^~~~~ kernel/bpf/memalloc.c:642:26: note: initialize the variable 'objcg' to silence this warning struct obj_cgroup *objcg; ^ = NULL 1 warning generated. vim +/objcg +665 kernel/bpf/memalloc.c 637 638 int bpf_mem_alloc_percpu_unit_init(struct bpf_mem_alloc *ma, int size) 639 { 640 int cpu, i, err = 0, unit_size, percpu_size; 641 struct bpf_mem_caches *cc, __percpu *pcc; 642 struct obj_cgroup *objcg; 643 struct bpf_mem_cache *c; 644 645 i = bpf_mem_cache_idx(size); 646 if (i < 0) 647 return -EINVAL; 648 649 /* room for llist_node and per-cpu pointer */ 650 percpu_size = LLIST_NODE_SZ + sizeof(void *); 651 652 pcc = ma->caches; 653 unit_size = sizes[i]; 654 655 #ifdef CONFIG_MEMCG_KMEM 656 objcg = get_obj_cgroup_from_current(); 657 #endif 658 for_each_possible_cpu(cpu) { 659 cc = per_cpu_ptr(pcc, cpu); 660 c = &cc->cache[i]; 661 if (cpu == 0 && c->unit_size) 662 goto out; 663 664 c->unit_size = unit_size; > 665 c->objcg = objcg; 666 c->percpu_size = percpu_size; 667 c->tgt = c; 668 669 init_refill_work(c); 670 prefill_mem_cache(c, cpu); 671 672 if (cpu == 0) { 673 err = check_obj_size(c, i); 674 if (err) { 675 drain_mem_cache(c); 676 memset(c, 0, sizeof(*c)); 677 goto out; 678 } 679 } 680 } 681 682 out: 683 return err; 684 } 685 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
