tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/wip2 head: fb0089110c5e29151c75028add05458ad2bf8a68 commit: fb0089110c5e29151c75028add05458ad2bf8a68 [5/5] sched: Massage set_cpus_allowed config: powerpc-allyesconfig (attached as .config) compiler: powerpc64-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 git checkout fb0089110c5e29151c75028add05458ad2bf8a68 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 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 >>): 1908 | u32 flags) | ^~~ kernel/sched/core.c: In function 'set_cpus_allowed_ptr': 1986 | return __set_cpus_allowed_ptr(p, new_mask, 0); | ^~~~~~~~~~~~~~~~~~~~~~ | set_cpus_allowed_ptr kernel/sched/core.c: At top level: kernel/sched/core.c:2412:6: warning: no previous prototype for 'sched_set_stop_task' [-Wmissing-prototypes] 2412 | void sched_set_stop_task(int cpu, struct task_struct *stop) | ^~~~~~~~~~~~~~~~~~~ kernel/sched/core.c: In function 'schedule_tail': kernel/sched/core.c:3798:13: warning: variable 'rq' set but not used [-Wunused-but-set-variable] 3798 | struct rq *rq; | ^~ kernel/sched/core.c: In function 'init_idle': 6641 | set_cpus_allowed_common(idle, cpumask_of(cpu)); | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:1831:6: note: declared here 1831 | void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask, u32 flags) | ^~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c: In function '__balance_push_cpu_stop': kernel/sched/core.c:6802:2: error: implicit declaration of function 'update_rq_clockrq'; did you mean 'update_rq_clock'? [-Werror=implicit-function-declaration] 6802 | update_rq_clockrq(); | ^~~~~~~~~~~~~~~~~ | update_rq_clock cc1: some warnings being treated as errors # https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?... git remote add peterz-queue https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git git fetch --no-tags peterz-queue sched/wip2 git checkout fb0089110c5e29151c75028add05458ad2bf8a68 vim +1908 kernel/sched/core.c 1896 1897 /* 1898 * Change a given task's CPU affinity. Migrate the thread to a 1899 * proper CPU and schedule it away if the CPU it's executing on 1900 * is removed from the allowed bitmask. 1901 * 1902 * NOTE: the caller must have a valid reference to the task, the 1903 * task must not exit() & deallocate itself prematurely. The 1904 * call is not atomic; no spinlocks may be held. 1905 */ 1906 static int __set_cpus_allowed_ptr(struct task_struct *p, 1907 const struct cpumask *new_mask 1909 { 1910 const struct cpumask *cpu_valid_mask = cpu_active_mask; 1911 unsigned int dest_cpu; 1912 struct rq_flags rf; 1913 struct rq *rq; 1914 int ret = 0; 1915 1916 rq = task_rq_lock(p, &rf); 1917 update_rq_clock(rq); 1918 1919 if (p->flags & PF_KTHREAD) { 1920 /* 1921 * Kernel threads are allowed on online && !active CPUs 1922 */ 1923 cpu_valid_mask = cpu_online_mask; 1924 } 1925 1926 /* 1927 * Must re-check here, to close a race against __kthread_bind(), 1928 * sched_setaffinity() is not guaranteed to observe the flag. 1929 */ 1930 if ((flags & SCA_CHECK) && (p->flags & PF_NO_SETAFFINITY)) { 1931 ret = -EINVAL; 1932 goto out; 1933 } 1934 1935 if (!(flags & SCA_MIGRATE_ENABLE) && cpumask_equal(&p->cpus_mask, new_mask)) 1936 goto out; 1937 1938 /* 1939 * Picking a ~random cpu helps in cases where we are changing affinity 1940 * for groups of tasks (ie. cpuset), so that load balancing is not 1941 * immediately required to distribute the tasks within their new mask. 1942 */ 1943 dest_cpu = cpumask_any_and_distribute(cpu_valid_mask, new_mask); 1944 if (dest_cpu >= nr_cpu_ids) { 1945 ret = -EINVAL; 1946 goto out; 1947 } 1948 1949 __do_set_cpus_allowed(p, new_mask, flags); 1950 1951 if (p->flags & PF_KTHREAD) { 1952 /* 1953 * For kernel threads that do indeed end up on online && 1954 * !active we want to ensure they are strict per-CPU threads. 1955 */ 1956 WARN_ON(cpumask_intersects(new_mask, cpu_online_mask) && 1957 !cpumask_intersects(new_mask, cpu_active_mask) && 1958 p->nr_cpus_allowed != 1); 1959 } 1960 1961 /* Can the task run on the task's current CPU? If so, we're done */ 1962 if (cpumask_test_cpu(task_cpu(p), new_mask)) 1963 goto out; 1964 1965 if (task_running(rq, p) || p->state == TASK_WAKING) { 1966 struct migration_arg arg = { p, dest_cpu }; 1967 /* Need help from migration thread: drop lock and wait. */ 1968 task_rq_unlock(rq, p, &rf); 1969 stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); 1970 return 0; 1971 } else if (task_on_rq_queued(p)) { 1972 /* 1973 * OK, since we're going to drop the lock immediately 1974 * afterwards anyway. 1975 */ 1976 rq = move_queued_task(rq, &rf, p, dest_cpu); 1977 } 1978 out: 1979 task_rq_unlock(rq, p, &rf); 1980 1981 return ret; 1982 } 1983 1984 int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) 1985 { 1987 } 1988 EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); 1989 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org