QProfiler stands for QEMU Profiler and is a simple tool to profile a guest by measuring where the time is spent during its execution. QProfiler samples the cpu registers to count what are the most used functions. The tool does so by relying on the QMP interface. This procedure does not need any instrumentation in the guest.
The repo includes a simple example to profile the appliance HelloWorld which is based on Toro. To try it, you need to clone the repo, install qemu and then execute the following command:
kvm -nographic -vnc :0 -drive format=raw,file=HelloWorld.img -smp 1 -m 256 -qmp unix:./qmp-sock,server,nowaitIn a different terminal, execute:
./qprofiler --path=./qmp-sock --duration=10 --frequency=0.05 --filename=HelloWorldNote that you have to tell qprofiler the path to the socket previously created by QEMU. You will get something like:
1 WRITE_PORTB at Arch.pas:303
18 MOVE at system.pas:1981Compile your multiboot kernel with -gl flag to add debug symbols. Then, run qemu by using the -kernel YourKernel option and add -qmp unix:./qmp-sock,server,nowait to redirect qmp to a socket. To lauch qprofile, execute:
./qprofiler --path=./qmp-sock --duration=10 --frequency=0.05 --filename=YouKernelThe line above tells qpprofiler to test during 10 seconds and to sample Qemu every 0.05 seconds. In addition, the line specifies in path the socket and in filename the binary. If everything worked well after 10 seconds, you are going to get something like:
1 WRITE_PORTB at Arch.pas:303
18 MOVE at system.pas:1981This represents in which functions the 10 seconds have been elapsed.
For the moment, Qprofiler only samples the booting core.
GPLv2
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent