tree: https://github.com/alibaba/cloud-kernel.git linux-next head: 1d6103ae4cce545c231de9498d0e70564e7b734e commit: 61e5885959be9af0b6942ec2a3ea0e7ccc48bf05 [11098/11168] alinux: sched: Introduce per-cgroup idle accounting config: x86_64-randconfig-a003-20200526 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 3393cc4cebf9969db94dc424b7a2b6195589c33b) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu git checkout 61e5885959be9af0b6942ec2a3ea0e7ccc48bf05 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, ^ 1 warning generated. 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 +/cpuset_write_resmask +1695 kernel/cgroup/cpuset.c 5be7a4792a31df6 kernel/cpuset.c Paul Menage 2008-05-06 1691 e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1692 /* e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1693 * Common handling for a write to a "cpus" or "mems" file. e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1694 */ 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 @1695 static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 1696 char *buf, size_t nbytes, loff_t off) e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1697 { 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 1698 struct cpuset *cs = css_cs(of_css(of)); 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1699 struct cpuset *trialcs; 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1700 int retval = -ENODEV; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1701 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 1702 buf = strstrip(buf); 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 1703 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1704 /* 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1705 * CPU or memory hotunplug may leave @cs w/o any execution 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1706 * resources, in which case the hotplug code asynchronously updates 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1707 * configuration and transfers all tasks to the nearest ancestor 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1708 * which can execute. 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1709 * 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1710 * As writes to "cpus" or "mems" may restore @cs's execution 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1711 * resources, wait for the previously scheduled operations before 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1712 * proceeding, so that we don't end up keep removing tasks added 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1713 * after execution capability is restored. 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1714 * 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1715 * cpuset_hotplug_work calls back into cgroup core via 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1716 * cgroup_transfer_tasks() and waiting for it from a cgroupfs 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1717 * operation like this one can lead to a deadlock through kernfs 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1718 * active_ref protection. Let's break the protection. Losing the 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1719 * protection is okay as we check whether @cs is online after 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1720 * grabbing cpuset_mutex anyway. This only happens on the legacy 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1721 * hierarchies. 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1722 */ 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1723 css_get(&cs->css); 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1724 kernfs_break_active_protection(of->kn); 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1725 flush_work(&cpuset_hotplug_work); 3a5a6d0c2b0391e kernel/cpuset.c Tejun Heo 2013-01-07 1726 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1727 mutex_lock(&cpuset_mutex); 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1728 if (!is_cpuset_online(cs)) 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1729 goto out_unlock; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1730 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1731 trialcs = alloc_trial_cpuset(cs); b75f38d659e6fc7 kernel/cpuset.c Li Zefan 2011-03-04 1732 if (!trialcs) { b75f38d659e6fc7 kernel/cpuset.c Li Zefan 2011-03-04 1733 retval = -ENOMEM; 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1734 goto out_unlock; b75f38d659e6fc7 kernel/cpuset.c Li Zefan 2011-03-04 1735 } 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1736 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 1737 switch (of_cft(of)->private) { e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1738 case FILE_CPULIST: 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1739 retval = update_cpumask(cs, trialcs, buf); e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1740 break; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1741 case FILE_MEMLIST: 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1742 retval = update_nodemask(cs, trialcs, buf); e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1743 break; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1744 default: e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1745 retval = -EINVAL; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1746 break; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1747 } 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1748 645fcc9d2f6946f kernel/cpuset.c Li Zefan 2009-01-07 1749 free_trial_cpuset(trialcs); 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1750 out_unlock: 5d21cc2db040d01 kernel/cpuset.c Tejun Heo 2013-01-07 1751 mutex_unlock(&cpuset_mutex); 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1752 kernfs_unbreak_active_protection(of->kn); 76bb5ab8f6e3e7b kernel/cpuset.c Tejun Heo 2014-06-30 1753 css_put(&cs->css); e93ad19d0564839 kernel/cpuset.c Tejun Heo 2016-01-19 1754 flush_workqueue(cpuset_migrate_mm_wq); 451af504df0c62f kernel/cpuset.c Tejun Heo 2014-05-13 1755 return retval ?: nbytes; e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1756 } e37123953292146 kernel/cpuset.c Paul Menage 2008-07-25 1757 :::::: The code at line 1695 was first introduced by commit :::::: 451af504df0c62f695a69b83c250486e77c66378 cgroup: replace cftype->write_string() with cftype->write() :::::: TO: Tejun Heo <tj(a)kernel.org&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