A customer using nohz_full has experienced the following interruption: oslat-1004510 [018] timer_cancel: timer=0xffff90a7ca663cf8 oslat-1004510 [018] timer_expire_entry: timer=0xffff90a7ca663cf8 function=delayed_work_timer_fn now=4709188240 baseclk=4709188240 oslat-1004510 [018] workqueue_queue_work: work struct=0xffff90a7ca663cd8 function=fb_flashcursor workqueue=events_power_efficient req_cpu=8192 cpu=18 oslat-1004510 [018] workqueue_activate_work: work struct 0xffff90a7ca663cd8 oslat-1004510 [018] sched_wakeup: kworker/18:1:326 [120] CPU:018 oslat-1004510 [018] timer_expire_exit: timer=0xffff90a7ca663cf8 oslat-1004510 [018] irq_work_entry: vector=246 oslat-1004510 [018] irq_work_exit: vector=246 oslat-1004510 [018] tick_stop: success=0 dependency=SCHED oslat-1004510 [018] hrtimer_start: hrtimer=0xffff90a70009cb00 function=tick_sched_timer/0x0 ... oslat-1004510 [018] softirq_exit: vec=1 [action=TIMER] oslat-1004510 [018] softirq_entry: vec=7 [action=SCHED] oslat-1004510 [018] softirq_exit: vec=7 [action=SCHED] oslat-1004510 [018] tick_stop: success=0 dependency=SCHED oslat-1004510 [018] sched_switch: oslat:1004510 [120] R ==> kworker/18:1:326 [120] kworker/18:1-326 [018] workqueue_execute_start: work struct 0xffff90a7ca663cd8: function fb_flashcursor kworker/18:1-326 [018] workqueue_queue_work: work struct=0xffff9078f119eed0 function=drm_fb_helper_damage_work workqueue=events req_cpu=8192 cpu=18 kworker/18:1-326 [018] workqueue_activate_work: work struct 0xffff9078f119eed0 kworker/18:1-326 [018] timer_start: timer=0xffff90a7ca663cf8 function=delayed_work_timer_fn ... Set wq_power_efficient to true, in case nohz_full is enabled. This makes the power efficient workqueue be unbounded, which allows workqueue items there to be moved to HK CPUs.
Showing the changes to kernel/workqueue.c (1 of 1 file). Show all
Unified · Split
| @@ -6638,6 +6638,13 @@ void __init workqueue_init_early(void) · 6637 unmodified lines | ||
| 6638 | 6638 | wq_update_pod_attrs_buf = alloc_workqueue_attrs(); |
| 6639 | 6639 | BUG_ON(!wq_update_pod_attrs_buf); |
| 6640 | 6640 | |
| 6641 | + /* | |
| 6642 | + * If nohz_full is enabled, set power efficient workqueue as unbound. | |
| 6643 | + * This allows workqueue items to be moved to HK CPUs. | |
| 6644 | + */ | |
| 6645 | + if (housekeeping_enabled(HK_TYPE_TICK)) | |
| 6646 | + wq_power_efficient = true; | |
| 6647 | + | |
| 6641 | 6648 | /* initialize WQ_AFFN_SYSTEM pods */ |
| 6642 | 6649 | pt->pod_cpus = kcalloc(1, sizeof(pt->pod_cpus[0]), GFP_KERNEL); |
| 6643 | 6650 | pt->pod_node = kcalloc(1, sizeof(pt->pod_node[0]), GFP_KERNEL); |