On Sat, Apr 30, 2011 at 6:00 PM, Chris Thompson <cth...@cs.umn.edu> wrote:
> I'm trying to add a trace to qemu-kvm that will log the value of the vcpu's
> clock when a specific interrupt gets pushed. I'm working with
> qemu-kvm-0.14.0 on the 2.6.32-31 kernel. I've added the following to
> kvm_arch_try_push_interrupts in qemu-kvm-x86.c:
>
> if (irq == 41) {
> // Get the VCPU's TSC
> struct kvm_clock_data clock;
> kvm_vcpu_ioctl(env, KVM_GET_CLOCK, &clock);
> uint64_t ticks = clock.clock;
> trace_kvm_clock_at_injection(ticks);
> }
>
> And here's the trace event I added:
>
> kvm_clock_at_injection(uint64_t ticks) "interrupt 41 at clock %"PRIu64""
>
> I have that trace and the virtio_blk_req_complete trace enabled. An excerpt
> from the resulting trace output from simpletrace.py:
>
> virtio_blk_req_complete 288390365546367 30461.681 req=46972352 status=0
> kvm_clock_at_injection 288390365546578 0.211 ticks=46972352
> virtio_blk_req_complete 288390394870065 29323.487 req=46972352 status=0
> kvm_clock_at_injection 288390394870276 0.211 ticks=46972352
Did you modify simpletrace.py? The 288390365546367 field is should
not be there. The output format should be:
<trace-event-name> <delta-microseconds> [<arg0>=<val0>...]
It looks like your simpletrace.py may be pretty-printing trace records
incorrectly.
If you have a public git tree you can link to I'd be happy to check
that simpletrace.py is working.
Stefan
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