On Fri, May 21, 2021 at 07:34:41AM +0900, Sergey Senozhatsky wrote: > On (21/05/20 07:57), Paul E. McKenney wrote: > > > > > > Sounds good. I can cook a patch and run some tests. > > > Or do you want to send a patch? > > > > Given that you have the test setup, things might go faster if you do > > the patch, especially taking timezones into consideration. Of course, > > if you run into difficulties, you know where to find me. > > OK. Sounds good to me. > > > > While VCPU-2 has PVCLOCK_GUEST_STOPPED set (resuming) and is in > > > check_cpu_stall(), the VCPU-3 is executing: > > > > > > apic_timer_interrupt() > > > tick_irq_enter() > > > tick_do_update_jiffies64() > > > do_timer() > > > > OK, but the normal grace period time is way less than one second, and > > the stall timeout in mainline is 21 seconds, so that would be a -lot- > > of jiffies of skew. Or does the restarting really take that long a time? > > That's a good question. I see huge jiffies spike in the logs. > I suspect that resuming a VM can take some time, especially on a "not > powerful at all" overcommitted host (more virtual CPUs than physical > ones). I really am just asking the question. ;-) After all, if restarting a VM can take that long, then it can take that long. Thanx, Paul
