Performance measurement

[sterbl . ta]

Sorry I am not sure if this is the right place to ask but this is the only mailing list that most relevant. Apologize if this is not, and please let me know which place I should check. Thank you.

My main question is I want to measure the boot time of image running using qemu. And I come across to this repo https://github.com/stefano-garzarella/qemu-boot-time#how-to-use which can achieve my goal.

So I try replacing qemu startup command in How to use section with mine below

qemu-system-x86_64 -enable-kvm \

    -drive "file=disk.img,if=virtio" -drive "file=seed.img,if=virtio,format=raw"  \

    -device virtio-net-pci,netdev=net00 --netdev type=user,id=net00 \

    -m 512 -nographic

perf record command generates qemu_perf.data file without a problem. 
But the problem raises when trying to run the command 

perf script -s qemu-boot-time/perf-script/qemu-perf-script.py -i \
    qemu_perf.data

It throws

in trace_begin
Traceback (most recent call last):
  File "qemu-boot-time/perf-script/qemu-perf-script.py", line 195, in kvm__kvm_entry
    if (events.traces[pid].qemu_init_end != 0):
AttributeError: 'collections.defaultdict' object has no attribute 'qemu_init_end'
Fatal Python error: problem in Python trace event handler

Even after export env variable PERF_EXEC_PATH to /path/to/linux-source-5.4/tools/perf (where Core.py, Utils.py files located in linux kernel source 5.4)

So my questions:

How can I fix this?

Otherwise in qemu, any command or anyway that I can measure the boot time of a specific image created?

Many thanks for advice.