I'm running an ARM full system simulation in gem5 and the configurations I'm using in the commandline is:
./build/ARM/gem5.perf configs/example/arm/fs_bigLITTLE.py
--kernel=/home/ting-bazinga/gem5/linux-arm-gem5/vmlinux
--caches
--disk /home/ting-bazinga/gem5/fs_imgs/disks/aarch64-ubuntu-trusty-headless.img
--bootscript /home/ting-bazinga/gem5/fs_imgs/test.rcS
From the post Using perf_event with the ARM PMU inside gem5 I presume obtaining PMU events in gem5 is possible. However I didn't found the exact method for how to do that.
perf can be used to obtain PMU information, on my local machine I can just download the linux-tools-common in my terminal to use that tool. But I can't do the same with the simulation. There isn't a perf binary that I can just find online (or maybe anyone can give a hint of how to write this kind of binary?) And I also tried downloading the linux-tools-common package, copying it into the disk image then using the makefile to compile it. But somehow the makefile does not work in the simulated system.
Or can the PMU events be abtained using C code? In the post I mentioned above someone used C code to count the number of mispredicted branches by the branch predictor unit during a specific task. And I can use perf_event_open to obtain number of instruction during an execution. However running the perf_event_open code requires root, but I cannot use sudo in the simulated system.
Can anybody give me some instructions on how to obtain PMU events in gem5? Many thanks.
