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authorMarcelo Tosatti <mtosatti@redhat.com>2024-01-19 16:54:39 +0100
committerTejun Heo <tj@kernel.org>2024-01-20 00:55:47 +0100
commit7bd20b6b87183db2ebf789bcf9d0aa6d06a0defb (patch)
treefa82e3cfad3483764303d5e898e5bb6b2e1e9113 /kernel/workqueue.c
parentworkqueue: Add rcu lock check at the end of work item execution (diff)
downloadlinux-7bd20b6b87183db2ebf789bcf9d0aa6d06a0defb.tar.xz
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workqueue: mark power efficient workqueue as unbounded if nohz_full enabled
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. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r--kernel/workqueue.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index aec3efbaaf93..8ca65665efe9 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -6638,6 +6638,13 @@ void __init workqueue_init_early(void)
wq_update_pod_attrs_buf = alloc_workqueue_attrs();
BUG_ON(!wq_update_pod_attrs_buf);
+ /*
+ * If nohz_full is enabled, set power efficient workqueue as unbound.
+ * This allows workqueue items to be moved to HK CPUs.
+ */
+ if (housekeeping_enabled(HK_TYPE_TICK))
+ wq_power_efficient = true;
+
/* initialize WQ_AFFN_SYSTEM pods */
pt->pod_cpus = kcalloc(1, sizeof(pt->pod_cpus[0]), GFP_KERNEL);
pt->pod_node = kcalloc(1, sizeof(pt->pod_node[0]), GFP_KERNEL);