[Ask for Help]LBR usage in kernel

From: 陈弋玺
Date: Thu Feb 20 2020 - 08:53:25 EST

Hi experts,
We want to try to retreive callchains of some perf events from LBR rather than frame stacks, as the information in frame stacks would be optimized by compiler. After investigating the usage of LBR in kernel, we found that LBR can only operated via Intel PMU, that means for now only callchains of hardware events can be retrieved from LBR. Is that correct?
If yes, I wonder if callchains of other perf events(eg. tracepoint, software events) can be retrieved from LBR? Or only callchains of events on PMU can be retrieved from LBR as there are some hardware restrictions?

Thanks for any help you can offer!

Best Regards,
Yixi Chen