Re: [Qemu-devel] how could I analysis the trace log?

[Andreas Färber]

Hi,

Am 12.02.2012 05:32, schrieb Wei Yang:
> I enable the trace function with --enable-trace-backend=simple and I
> create the event file like this
> g_realloc
> g_malloc
> 
> Then I start the qemu with following command.
> ./i386-softmmu/qemu-system-i386 -enable-kvm -drive
> file=../../kvm/ubuntu.img -boot dc -m 512 -usb
>  -monitor stdio -trace events=qemu_trace_events,file=qemu_trace.log
> 
> After some run time, I run the script like:
> ./scripts/simpletrace.py qemu_trace_events_parse qemu_trace.log
> 
> The qemu_trace_events_parse is :
> g_realloc(addr)
> g_malloc(addr)
> 
> The output looks like:
> g_malloc 1.831 addr=0xb945d1f0
> g_malloc 2.498 addr=0xb945d1f0
> g_realloc 4.715 addr=0x10
> g_realloc 1.520 addr=0xc
> g_realloc 1.505 addr=0xc
> 
> The steps I used is correct?

Not quite. IIRC you need to pass in path/to/qemu/trace-events with the
full list of events you were using at the time of tracing (trace file
uses index of event). That file also contains a format string from which
you can infer what the arguments mean.

> I just guess the format of input events file of the simpletrace.py.

> For so many available events, how could I specify the format of all
> those events?

Not knowing Python too well myself, I just wrote a small analysis script
from scratch for my specific task, based on the simpletrace source code.

Andreas

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