Re: [PATCHv3 00/12] perf tools: Display eBPF code in intel_pt trace

[Jiri Olsa <jolsa@redhat.com>]

On Thu, May 30, 2019 at 06:54:39PM +0800, Leo Yan wrote:
> Hi Jiri,
> 
> On Wed, May 08, 2019 at 03:19:58PM +0200, Jiri Olsa wrote:
> > hi,
> > this patchset adds dso support to read and display
> > bpf code in intel_pt trace output. I had to change
> > some of the kernel maps processing code, so hopefully
> > I did not break too many things ;-)
> > 
> > It's now possible to see bpf code flow via:
> > 
> >   # perf-with-kcore record pt -e intel_pt//ku -- sleep 1
> >   # perf-with-kcore script pt --insn-trace --xed
> 
> This is very interesting work for me!
> 
> I want to verify this feature with Arm CoreSight trace, I have one
> question so that I have more direction for the tesing:
> 
> What's the bpf program you are suing for the testing?  e.g. some
> testing program under the kernel's folder $kernel/samples/bpf?
> Or you uses perf command to launch bpf program?

for this I was using tools/testing/selftests/bpf/test_verifier

I isolated some tests and ran the perf on top of them, like:

  # perf-with-kcore record pt -e intel_pt//ku -- ./test_verifier ...

I had to add some small sleep before the test_verifier exit,
so the perf bpf thread could catch up and download the program
details before test_verifier exited.

jirka

> 
> [...]
> 
> Thanks
> Leo Yan