Hi Jonathan, [FYI, it's a private test report for your RFC patch.] [auto build test ERROR on tip/sched/core] [also build test ERROR on next-20210125] [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] url: https://github.com/0day-ci/linux/commits/Jonathan-Schwender/sched-rt-Fix-... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 7a976f77bb962ce9486e09eb839aa135619b54f3 config: h8300-randconfig-r022-20210201 (attached as .config) compiler: h8300-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/f2f23b24036429e0d47deb121f16367a2... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jonathan-Schwender/sched-rt-Fix-RT-group-throttling-with-nohz_full/20210201-173818 git checkout f2f23b24036429e0d47deb121f16367a2444247e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=h8300 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): kernel/sched/rt.c:669:6: warning: no previous prototype for 'sched_rt_bandwidth_account' [-Wmissing-prototypes] 669 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/rt.c: In function 'do_sched_rt_period_timer': 876 | && housekeeping_cpu(this_rq()->cpu, HK_FLAG_TIMER))) { | ^~ vim +876 kernel/sched/rt.c 853 854 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) 855 { 856 int i, idle = 1, throttled = 0; 857 const struct cpumask *span; 858 859 span = sched_rt_period_mask(); 860 #ifdef CONFIG_RT_GROUP_SCHED 861 /* 862 * FIXME: isolated CPUs should really leave the root task group, 863 * whether they are isolcpus or were isolated via cpusets, lest 864 * the timer run on a CPU which does not service all runqueues, 865 * potentially leaving other CPUs indefinitely throttled. If 866 * isolation is really required, the user will turn the throttle 867 * off to kill the perturbations it causes anyway. Meanwhile, 868 * this maintains functionality for boot and/or troubleshooting. 869 * If nohz_full is active and the timer was offloaded to a 870 * housekeeping CPU, sched_rt_period_mask() will not contain 871 * the isolated CPU. To prevent indefinite throttling of tasks 872 * on isolated CPUs, housekeeping CPUs service all online CPUs. 873 */ 874 if (rt_b == &root_task_group.rt_bandwidth 875 || (housekeeping_enabled(HK_FLAG_TIMER) 877 span = cpu_online_mask; 878 } 879 #endif 880 for_each_cpu(i, span) { 881 int enqueue = 0; 882 struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); 883 struct rq *rq = rq_of_rt_rq(rt_rq); 884 int skip; 885 886 /* 887 * When span == cpu_online_mask, taking each rq->lock 888 * can be time-consuming. Try to avoid it when possible. 889 */ 890 raw_spin_lock(&rt_rq->rt_runtime_lock); 891 if (!sched_feat(RT_RUNTIME_SHARE) && rt_rq->rt_runtime != RUNTIME_INF) 892 rt_rq->rt_runtime = rt_b->rt_runtime; 893 skip = !rt_rq->rt_time && !rt_rq->rt_nr_running; 894 raw_spin_unlock(&rt_rq->rt_runtime_lock); 895 if (skip) 896 continue; 897 898 raw_spin_lock(&rq->lock); 899 update_rq_clock(rq); 900 901 if (rt_rq->rt_time) { 902 u64 runtime; 903 904 raw_spin_lock(&rt_rq->rt_runtime_lock); 905 if (rt_rq->rt_throttled) 906 balance_runtime(rt_rq); 907 runtime = rt_rq->rt_runtime; 908 rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime); 909 if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { 910 rt_rq->rt_throttled = 0; 911 enqueue = 1; 912 913 /* 914 * When we're idle and a woken (rt) task is 915 * throttled check_preempt_curr() will set 916 * skip_update and the time between the wakeup 917 * and this unthrottle will get accounted as 918 * 'runtime'. 919 */ 920 if (rt_rq->rt_nr_running && rq->curr == rq->idle) 921 rq_clock_cancel_skipupdate(rq); 922 } 923 if (rt_rq->rt_time || rt_rq->rt_nr_running) 924 idle = 0; 925 raw_spin_unlock(&rt_rq->rt_runtime_lock); 926 } else if (rt_rq->rt_nr_running) { 927 idle = 0; 928 if (!rt_rq_throttled(rt_rq)) 929 enqueue = 1; 930 } 931 if (rt_rq->rt_throttled) 932 throttled = 1; 933 934 if (enqueue) 935 sched_rt_rq_enqueue(rt_rq); 936 raw_spin_unlock(&rq->lock); 937 } 938 939 if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) 940 return 1; 941 942 return idle; 943 } 944 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org