Hi, On Fri, Jul 26, 2024 at 12:46 PM richard clark <richard.xnu.clark@xxxxxxxxx> wrote: > > Hi, > > On Wed, Jul 10, 2024 at 7:22 PM Neeraj upadhyay <neeraj.iitr10@xxxxxxxxx> wrote: > > > > Hello Richard, > > > > On Wed, Jul 10, 2024 at 1:56 PM richard clark > > <richard.xnu.clark@xxxxxxxxx> wrote: > > > > > > Hi, > > > I am running a Ubuntu 20.04.5 LTS on Nvidia Jetson AGX Orin platform > > > with 12-cores as a guestOS, the kernel version is - 6.1.83-rt28. > > > Kernel cmdline is: > > > 'root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 mminit_loglevel=4 > > > console=ttyTCU0,115200 console=tty0 firmware_class.path=/etc/firmware > > > fbcon=map:0 net.ifnames=0' > > > > > > The cyclictest command 'cyclictest -Smp99 -H 3000 > > > --histfile=orin_idle_hyp_4h.hist -D 4h' will hang randomly during the > > > test, then the minicom console will show below messages: > > > ... > > > > > > [97619.450889] [CPU11-E] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > > > [97619.450894] [CPU11-E] rcu: 1-...!: (0 ticks this GP) > > > idle=dc88/0/0x0 softirq=0/0 fqs=2 (false positive?) > > > [97619.450914] [ CPU1-E] NMI backtrace for cpu 1 > > > [97619.451912] [CPU11-E] rcu: rcu_preempt kthread timer wakeup didn't > > > happen for 5251 jiffies! g6029253 f0x0 RCU_GP_WAIT_FQS(5) > > > ->state=0x402 > > > [97619.451916] [CPU11-E] rcu: Possible timer handling issue on cpu=1 > > > timer-softirq=342864 > > > > This log indicates that jiffies timers are not getting handled on CPU1, due to > > which GP kthread was not woken up. Can you check irq, softirq and timer traces > > on CPU1, to see if the softirqs/timers are getting served on this CPU? > > > Please ignore this issue. As narrow down this is an issue from > homemade hypervisor which unmasks the vtimer ctrl.IMASK bit by > accident, so the vcpu can't get further vtimer interrupt, thus the > issue happens... > Thanks > Great! Thanks for providing details on the root cause! - Neeraj > > > > - Neeraj > >