On Thu, Sep 28, 2017 at 02:14:15AM -0700, Sasha Levin wrote: > On Thu, Sep 7, 2017 at 8:03 AM, Peter Zijlstra <[email protected]> wrote: > > Migrating tasks to offline CPUs is a pretty big fail, warn about it. > > Hey Peter, > > This seems to get hit on the latest -next: > > [2035565360.446794] Unregister pv shared memory for cpu 2 > [2035565360.467930] numa_remove_cpu cpu 2 node 2: mask now 6 > [2035565360.471431] ------------[ cut here ]------------ > [2035565360.472548] WARNING: CPU: 2 PID: 24 at > kernel/sched/core.c:1178 > set_task_cpu (kernel/sched/core.c:1157) > [2035565360.473840] Modules linked in: > [2035565360.474632] CPU: 2 PID: 24 Comm: migration/2 Not tainted > > 4.14.0-rc2-next-20170927+ #252
Urgh, weird. That really shouldn't happen. Can you easily reproduce? > [2035565360.491836] Call Trace: > [2035565360.492301] <IRQ> > [2035565360.492710] detach_task.isra.80 (kernel/sched/fair.c:6816) > [2035565360.493430] load_balance (./include/linux/list.h:78 > > kernel/sched/fair.c:6902 kernel/sched/fair.c:8201) > [2035565360.494094] ? find_busiest_group (kernel/sched/fair.c:8133) > [2035565360.494861] ? rebalance_domains (kernel/sched/fair.c:8785) > [2035565360.495571] rebalance_domains (kernel/sched/fair.c:8829) > [2035565360.496292] ? find_next_bit (lib/find_bit.c:65) > [2035565360.496961] ? pick_next_task_fair (kernel/sched/fair.c:8779) > [2035565360.497753] ? check_preemption_disabled (lib/smp_processor_id.c:52) > [2035565360.498574] run_rebalance_domains (kernel/sched/fair.c:9052) > [2035565360.499318] ? check_preemption_disabled (lib/smp_processor_id.c:52) > [2035565360.500388] __do_softirq (kernel/softirq.c:284 > > ./include/linux/jump_label.h:141 ./include/trace/events/irq.h:141 > > kernel/softirq.c:285) > [2035565360.501039] ? hrtimer_interrupt (kernel/time/hrtimer.c:1370) > [2035565360.502014] irq_exit (kernel/softirq.c:364 kernel/softirq.c:405) > [2035565360.502598] smp_apic_timer_interrupt > > (./arch/x86/include/asm/irq_regs.h:26 > arch/x86/kernel/apic/apic.c:1043) > [2035565360.503605] apic_timer_interrupt (arch/x86/entry/entry_64.S:770) > [2035565360.504313] </IRQ>
