id summary reporter owner description type status component version resolution keywords cc guest host 20131 rcu_sched detected stalls on CPUs/tasks: linux guest and host ?ryzen issue RT_db "Linux debian guest on Debian host Virtualbox 6.1.16 Host: Linux 5.6.0-0.bpo.2-amd64 #1 SMP Debian 5.6.14-2~bpo10+1 (2020-06-09) x86_64 GNU/Linux Debian 10 AMD Ryzen 9 3900X 12-Core 32Gb ram guest 4 cores, 4gb ram dmesg: [ 225.539622] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 225.540724] rcu: 0-...!: (27 ticks this GP) idle=c50/0/0x0 softirq=2529/2 530 fqs=0 [ 225.541761] rcu: 1-...!: (0 ticks this GP) idle=ac8/0/0x0 softirq=2101/21 01 fqs=0 [ 225.542767] rcu: 3-...!: (26 ticks this GP) idle=99c/0/0x0 softirq=2173/2 174 fqs=0 [ 225.543767] (detected by 2, t=5271 jiffies, g=2529, q=2) [ 225.543770] Sending NMI from CPU 2 to CPUs 0: [ 225.543825] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0 x10 [ 225.544771] Sending NMI from CPU 2 to CPUs 1: [ 225.544797] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0 x10 [ 225.545769] Sending NMI from CPU 2 to CPUs 3: [ 225.545796] NMI backtrace for cpu 3 skipped: idling at native_safe_halt+0xe/0 x10 [ 225.546769] rcu: rcu_sched kthread starved for 5272 jiffies! g2529 f0x0 RCU_G P_WAIT_FQS(5) ->state=0x402 ->cpu=1 [ 225.547792] rcu: RCU grace-period kthread stack dump: [ 225.548812] rcu_sched I 0 11 2 0x80004000 [ 225.548816] Call Trace: [ 225.548836] ? __schedule+0x2d8/0x760 [ 225.548838] ? __switch_to_asm+0x40/0x70 [ 225.548840] ? __switch_to_asm+0x40/0x70 [ 225.548842] schedule+0x4a/0xb0 [ 225.548843] schedule_timeout+0x15e/0x300 [ 225.548850] ? __next_timer_interrupt+0xd0/0xd0 [ 225.548853] rcu_gp_kthread+0x452/0x8d0 [ 225.548864] kthread+0xf9/0x130 [ 225.548869] ? kfree_call_rcu+0x10/0x10 [ 225.548870] ? kthread_park+0x90/0x90 [ 225.548872] ret_from_fork+0x22/0x40 [ 285.421645] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 285.422242] rcu: 0-...!: (0 ticks this GP) idle=da0/0/0x0 softirq=2535/25 35 fqs=0 [ 285.422780] rcu: 1-...!: (37 ticks this GP) idle=d4c/0/0x0 softirq=2103/2 103 fqs=0 [ 285.423305] rcu: 3-...!: (46 ticks this GP) idle=b84/0/0x0 softirq=2178/2 179 fqs=0 [ 285.423815] (detected by 2, t=5268 jiffies, g=2541, q=866) [ 285.423817] Sending NMI from CPU 2 to CPUs 0: [ 285.423858] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0 x10 [ 285.424818] Sending NMI from CPU 2 to CPUs 1: [ 285.424845] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0 x10 [ 285.425817] Sending NMI from CPU 2 to CPUs 3: [ 285.425847] NMI backtrace for cpu 3 skipped: idling at native_safe_halt+0xe/0 x10 [ 285.426815] rcu: rcu_sched kthread starved for 5268 jiffies! g2541 f0x0 RCU_G P_WAIT_FQS(5) ->state=0x402 ->cpu=0 [ 285.427228] rcu: RCU grace-period kthread stack dump: [ 285.427620] rcu_sched I 0 11 2 0x80004000 [ 285.427623] Call Trace: [ 285.427629] ? __schedule+0x2d8/0x760 [ 285.427630] ? __switch_to_asm+0x40/0x70 [ 285.427631] ? __switch_to_asm+0x40/0x70 [ 285.427633] schedule+0x4a/0xb0 [ 285.427634] schedule_timeout+0x15e/0x300 [ 285.427637] ? __next_timer_interrupt+0xd0/0xd0 [ 285.427640] rcu_gp_kthread+0x452/0x8d0 [ 285.427643] kthread+0xf9/0x130 [ 285.427645] ? kfree_call_rcu+0x10/0x10 [ 285.427647] ? kthread_park+0x90/0x90 [ 285.427648] ret_from_fork+0x22/0x40 System is unusable. Guest transferred from Intel i5 core system, were it worked perfectly. Same error in Debian 9, 10 and bullseye guests. Tried multiple combination of cores and ram - no effect. Interestingly Alpine 3.12 guest on same system has no problem. Current workaround: install guest additions on guest and error messages go. I've attached the virtualbox logs. host1 - is related to the dmesg output above. host2 and host3 are logs from the same system, just running longer. Many thanks for your help. " defect new other VirtualBox 6.1.16 Linux Linux