On 03/15/2017 08:53 AM, Wanpeng Li wrote: > Ping, :) > 2017-03-07 13:51 GMT+08:00 Wanpeng Li <kernellwp@xxxxxxxxx>: >> From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> >> >> The following warning can be triggered by hot-unplugging the CPU >> on which an active SCHED_DEADLINE task is running on: >> >> ------------[ cut here ]------------ >> WARNING: CPU: 7 PID: 0 at kernel/sched/sched.h:833 replenish_dl_entity+0x71e/0xc40 >> rq->clock_update_flags < RQCF_ACT_SKIP >> CPU: 7 PID: 0 Comm: swapper/7 Tainted: G B 4.11.0-rc1+ #24 >> Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 >> Call Trace: >> <IRQ> >> dump_stack+0x85/0xc4 >> __warn+0x172/0x1b0 >> warn_slowpath_fmt+0xb4/0xf0 >> ? __warn+0x1b0/0x1b0 >> ? debug_check_no_locks_freed+0x2c0/0x2c0 >> ? cpudl_set+0x3d/0x2b0 >> replenish_dl_entity+0x71e/0xc40 >> enqueue_task_dl+0x2ea/0x12e0 >> ? dl_task_timer+0x777/0x990 >> ? __hrtimer_run_queues+0x270/0xa50 >> dl_task_timer+0x316/0x990 >> ? enqueue_task_dl+0x12e0/0x12e0 >> ? enqueue_task_dl+0x12e0/0x12e0 >> __hrtimer_run_queues+0x270/0xa50 >> ? hrtimer_cancel+0x20/0x20 >> ? hrtimer_interrupt+0x119/0x600 >> hrtimer_interrupt+0x19c/0x600 >> ? trace_hardirqs_off+0xd/0x10 >> local_apic_timer_interrupt+0x74/0xe0 >> smp_apic_timer_interrupt+0x76/0xa0 >> apic_timer_interrupt+0x93/0xa0 >> >> The DL task will be migrated to a suitable later deadline rq once the DL >> timer fires and currnet rq is offline. The rq clock of the new rq should >> be updated. This patch fixes it by updating the rq clock after holding >> the new rq's rq lock. >> >> Cc: Juri Lelli <juri.lelli@xxxxxxx> >> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> >> Cc: Ingo Molnar <mingo@xxxxxxxxxx> >> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> >> Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> >> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> Reviewed-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> -- Daniel
