On Mon, Jul 27, 2009 at 03:05:40PM -0300, Glauber Costa wrote: > Hello, goodfellas > > I'm seeing a strange problem in our much loved qemu-kvm.git This bug shouldn't depend on qemu-kvm.git at all unless you are running with no-kvm-irqchip. The only things that involved in APIC timer calibration are tsc and APIC. (If you don't use apicpmtimer kernel parameter. Don't you?) What is you host HW? Which version of kernel modules are you using? Is your host overcommitted when this happens? Try to load the host with work (while(1)) and run the guest. Is it easier to reproduce problem this way? > It's been there before avi left for vacation, at least. > > The worst part, is that it doesn't happen always, and I don't > even think it is deterministic in its nature, IOW, there was nothing > I could do to make it more or less likely to happen. > > It's almost obviously interrupt related, but I can't determine more than that > As I haven't, and won't have the time to debug this in the near future, here's > the riddle for you all to appreciate: > > ..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1 > CPU0: QEMU Virtual CPU version 0.10.50 stepping 03 > Using local APIC timer interrupts. > Detected 0.000 MHz APIC timer. > ------------[ cut here ]------------ > WARNING: at kernel/time/clockevents.c:46 clockevent_delta2ns+0x37/0x72() (Not tainted) > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.27.5-117.fc10.x86_64 #1 > > Call Trace: > [<ffffffff810418f2>] warn_on_slowpath+0x60/0x90 > [<ffffffff81331c7e>] ? trace_hardirqs_on_thunk+0x3a/0x3c > [<ffffffff8159d140>] ? early_idt_handler+0x0/0x72 > [<ffffffff8132faf6>] ? printk+0x3c/0x3e > [<ffffffff8105cb9a>] clockevent_delta2ns+0x37/0x72 > [<ffffffff815ad263>] setup_boot_APIC_clock+0x1c2/0x24b > [<ffffffff8132faf6>] ? printk+0x3c/0x3e > [<ffffffff815ab8a6>] native_smp_prepare_cpus+0x29e/0x2cf > [<ffffffff8159d5a8>] kernel_init+0x59/0x214 > [<ffffffff81331c7e>] ? trace_hardirqs_on_thunk+0x3a/0x3c > [<ffffffff810116e9>] child_rip+0xa/0x11 > [<ffffffff81010a07>] ? restore_args+0x0/0x30 > [<ffffffff8159d54f>] ? kernel_init+0x0/0x214 > [<ffffffff810116df>] ? child_rip+0x0/0x11 > > ---[ end trace 4eaa2a86a8e2da22 ]--- > APIC frequency too slow, disabling apic timer > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
