tree: https://github.com/alibaba/cloud-kernel.git linux-next head: 4da723592714ee2993664252216d9d5b5a3df3eb commit: 61e5885959be9af0b6942ec2a3ea0e7ccc48bf05 [11098/11535] alinux: sched: Introduce per-cgroup idle accounting config: x86_64-rhel (attached as .config) compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 reproduce (this is a W=1 build): git checkout 61e5885959be9af0b6942ec2a3ea0e7ccc48bf05 # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): kernel/cgroup/cpuset.c: In function 'cpuset_cancel_attach': kernel/cgroup/cpuset.c:1515:17: warning: variable 'cs' set but not used [-Wunused-but-set-variable] 1515 | struct cpuset *cs; | ^~ kernel/cgroup/cpuset.c: In function 'update_cpumasks_hier': 963 | } | ^ kernel/cgroup/cpuset.c:2313: warning: Function parameter or member 'work' not described in 'cpuset_hotplug_workfn' kernel/cgroup/cpuset.c:2643: warning: Function parameter or member 'rotor' not described in 'cpuset_spread_node' vim +963 kernel/cgroup/cpuset.c 0b2f630a28d53b kernel/cpuset.c Miao Xie 2008-07-25 883 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 884 /* 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 885 * update_cpumasks_hier - Update effective cpumasks and tasks in the subtree 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 886 * @cs: the cpuset to consider 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 887 * @new_cpus: temp variable for calculating new effective_cpus 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 888 * 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 889 * When congifured cpumask is changed, the effective cpumasks of this cpuset 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 890 * and all its descendants need to be updated. 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 891 * 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 892 * On legacy hierachy, effective_cpus will be the same with cpu_allowed. 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 893 * 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 894 * Called with cpuset_mutex held 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 895 */ 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 896 static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus) 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 897 { 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 898 struct cpuset *cp; 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 899 struct cpumask added, deleted, old_cpus; 492eb21b98f88e kernel/cpuset.c Tejun Heo 2013-08-08 900 struct cgroup_subsys_state *pos_css; 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 901 bool need_rebuild_sched_domains = false; 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 902 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 903 rcu_read_lock(); 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 904 cpuset_for_each_descendant_pre(cp, pos_css, cs) { 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 905 struct cpuset *parent = parent_cs(cp); 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 906 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 907 cpumask_and(new_cpus, cp->cpus_allowed, parent->effective_cpus); 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 908 554b0d1c845e42 kernel/cpuset.c Li Zefan 2014-07-09 909 /* 554b0d1c845e42 kernel/cpuset.c Li Zefan 2014-07-09 910 * If it becomes empty, inherit the effective mask of the 554b0d1c845e42 kernel/cpuset.c Li Zefan 2014-07-09 911 * parent, which is guaranteed to have some CPUs. 554b0d1c845e42 kernel/cpuset.c Li Zefan 2014-07-09 912 */ b8d1b8ee93df8f kernel/cgroup/cpuset.c Waiman Long 2017-08-17 913 if (is_in_v2_mode() && cpumask_empty(new_cpus)) 554b0d1c845e42 kernel/cpuset.c Li Zefan 2014-07-09 914 cpumask_copy(new_cpus, parent->effective_cpus); 554b0d1c845e42 kernel/cpuset.c Li Zefan 2014-07-09 915 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 916 if (cpumask_empty(cp->effective_cpus)) 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 917 cpumask_copy(&old_cpus, parent->effective_cpus); 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 918 else 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 919 cpumask_copy(&old_cpus, cp->effective_cpus); 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 920 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 921 /* Skip the whole subtree if the cpumask remains the same. */ 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 922 if (cpumask_equal(new_cpus, cp->effective_cpus)) { 492eb21b98f88e kernel/cpuset.c Tejun Heo 2013-08-08 923 pos_css = css_rightmost_descendant(pos_css); 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 924 continue; 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 925 } 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 926 ec903c0c858e49 kernel/cpuset.c Tejun Heo 2014-05-13 927 if (!css_tryget_online(&cp->css)) 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 928 continue; 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 929 rcu_read_unlock(); 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 930 8447a0fee97443 kernel/cpuset.c Vladimir Davydov 2014-10-20 931 spin_lock_irq(&callback_lock); 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 932 cpumask_copy(cp->effective_cpus, new_cpus); 8447a0fee97443 kernel/cpuset.c Vladimir Davydov 2014-10-20 933 spin_unlock_irq(&callback_lock); 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 934 b8d1b8ee93df8f kernel/cgroup/cpuset.c Waiman Long 2017-08-17 935 WARN_ON(!is_in_v2_mode() && 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 936 !cpumask_equal(cp->cpus_allowed, cp->effective_cpus)); 734d45130cb4f6 kernel/cpuset.c Li Zefan 2014-07-09 937 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 938 /* add = new - old = new & (~old) */ 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 939 cpumask_andnot(&added, new_cpus, &old_cpus); 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 940 cpuacct_cpuset_changed(cs->css.cgroup, NULL, &added); 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 941 d66393e54e0a9d kernel/cpuset.c Tejun Heo 2014-02-13 942 update_tasks_cpumask(cp); 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 943 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 944 /* deleted = old - new = old & (~new) */ 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 945 cpumask_andnot(&deleted, &old_cpus, new_cpus); 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 946 cpuacct_cpuset_changed(cs->css.cgroup, &deleted, NULL); 61e5885959be9a kernel/cgroup/cpuset.c Yihao Wu 2020-03-10 947 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 948 /* 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 949 * If the effective cpumask of any non-empty cpuset is changed, 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 950 * we need to rebuild sched domains. 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 951 */ 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 952 if (!cpumask_empty(cp->cpus_allowed) && 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 953 is_sched_load_balance(cp)) 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 954 need_rebuild_sched_domains = true; 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 955 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 956 rcu_read_lock(); 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 957 css_put(&cp->css); 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 958 } 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 959 rcu_read_unlock(); 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 960 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 961 if (need_rebuild_sched_domains) 8b5f1c52dcd1ac kernel/cpuset.c Li Zefan 2014-07-09 962 rebuild_sched_domains_locked(); 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 @963 } 5c5cc62321d9df kernel/cpuset.c Li Zefan 2013-06-09 964 :::::: The code at line 963 was first introduced by commit :::::: 5c5cc62321d9df7a9a608346fc649c4528380c8f cpuset: allow to keep tasks in empty cpusets :::::: TO: Li Zefan <lizefan(a)huawei.com&gt; :::::: CC: Tejun Heo <tj(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org