Hi Srikar, Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/sched/core] [also build test WARNING on v4.19 next-20181019] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Srikar-Dronamraju/sched-core-Don-t-mix-isolcpus-and-housekeeping-CPUs/20181024-025019 config: i386-tinyconfig (attached as .config) compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: # save the attached .config to linux build tree make ARCH=i386 All warnings (new ones prefixed by >>): kernel/sched/core.c: In function 'sched_setaffinity': >> kernel/sched/core.c:4783:10: warning: assignment discards 'const' qualifier >> from pointer target type [-Wdiscarded-qualifiers] hk_mask = housekeeping_cpumask(HK_FLAG_DOMAIN); ^ vim +/const +4783 kernel/sched/core.c 4734 4735 long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) 4736 { 4737 cpumask_var_t cpus_allowed, new_mask; 4738 struct task_struct *p; 4739 struct cpumask *hk_mask; 4740 int retval; 4741 4742 rcu_read_lock(); 4743 4744 p = find_process_by_pid(pid); 4745 if (!p) { 4746 rcu_read_unlock(); 4747 return -ESRCH; 4748 } 4749 4750 /* Prevent p going away */ 4751 get_task_struct(p); 4752 rcu_read_unlock(); 4753 4754 if (p->flags & PF_NO_SETAFFINITY) { 4755 retval = -EINVAL; 4756 goto out_put_task; 4757 } 4758 if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { 4759 retval = -ENOMEM; 4760 goto out_put_task; 4761 } 4762 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { 4763 retval = -ENOMEM; 4764 goto out_free_cpus_allowed; 4765 } 4766 retval = -EPERM; 4767 if (!check_same_owner(p)) { 4768 rcu_read_lock(); 4769 if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { 4770 rcu_read_unlock(); 4771 goto out_free_new_mask; 4772 } 4773 rcu_read_unlock(); 4774 } 4775 4776 retval = security_task_setscheduler(p); 4777 if (retval) 4778 goto out_free_new_mask; 4779 4780 4781 cpuset_cpus_allowed(p, cpus_allowed); 4782 cpumask_and(new_mask, in_mask, cpus_allowed); > 4783 hk_mask = housekeeping_cpumask(HK_FLAG_DOMAIN); 4784 4785 /* 4786 * If the cpumask provided has CPUs that are part of isolated and 4787 * housekeeping_cpumask, then restrict it to just the CPUs that 4788 * are part of the housekeeping_cpumask. 4789 */ 4790 if (!cpumask_subset(new_mask, hk_mask) && 4791 cpumask_intersects(new_mask, hk_mask)) { 4792 pr_info("pid %d: Mix of isolcpus and non-isolcpus provided\n", 4793 p->pid); 4794 cpumask_and(new_mask, new_mask, hk_mask); 4795 } 4796 4797 /* 4798 * Since bandwidth control happens on root_domain basis, 4799 * if admission test is enabled, we only admit -deadline 4800 * tasks allowed to run on all the CPUs in the task's 4801 * root_domain. 4802 */ 4803 #ifdef CONFIG_SMP 4804 if (task_has_dl_policy(p) && dl_bandwidth_enabled()) { 4805 rcu_read_lock(); 4806 if (!cpumask_subset(task_rq(p)->rd->span, new_mask)) { 4807 retval = -EBUSY; 4808 rcu_read_unlock(); 4809 goto out_free_new_mask; 4810 } 4811 rcu_read_unlock(); 4812 } 4813 #endif 4814 again: 4815 retval = __set_cpus_allowed_ptr(p, new_mask, true); 4816 4817 if (!retval) { 4818 cpuset_cpus_allowed(p, cpus_allowed); 4819 if (!cpumask_subset(new_mask, cpus_allowed)) { 4820 /* 4821 * We must have raced with a concurrent cpuset 4822 * update. Just reset the cpus_allowed to the 4823 * cpuset's cpus_allowed 4824 */ 4825 cpumask_copy(new_mask, cpus_allowed); 4826 goto again; 4827 } 4828 } 4829 out_free_new_mask: 4830 free_cpumask_var(new_mask); 4831 out_free_cpus_allowed: 4832 free_cpumask_var(cpus_allowed); 4833 out_put_task: 4834 put_task_struct(p); 4835 return retval; 4836 } 4837 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
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