On Thu, May 30, 2019 at 08:57:09PM +0800, Leo Yan wrote: > Hi Jiri, > > On Thu, May 30, 2019 at 02:07:10PM +0200, Jiri Olsa wrote: > > 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 ... > > Thanks a lot for sharing the info and quick responsing. > > I tried to use the program $kernel/samples/bpf/sampleip to verify this > patch set, but seems eBPF dso is not contained properly; below is my > detailed steps: > > # In the first tty > # cd $kernel/samples/bpf/ > # ./sampleip -F 200 20 => sample ip with 200Hz for 20s > > # In the second tty > # perf-with-kcore record arm_test -e cs_etm/@20070000.etr/uk -- sleep 1 > > If I output DSO info with report command it give below info, which > doesn't contain any info for eBPF DSO? > > # perf-with-kcore report arm_test -F,dso > > # Samples: 6M of event 'branches:ku' > # Event count (approx.): 6340896 > # > # Shared Object > # .................. > # > [kernel.kallsyms] > ld-2.28.so > libc-2.28.so > libpthread-2.28.so > perf > sleep > [unknown] > > > 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. > > This seems to me for a 'real' eBPF program, do we also need extra sleep > so that perf bpf can save dso properly?
no it's just test_verifier exits right away with ebpf code, and perf does not have a chance to get the ebpf prog info your example above should be fine.. I'll try > > BTW, I have another question: to display eBPF code, except this feature > can be used by hardware tracing (e.g. intel_pt), it also can be used > by other PMU events and timer events, right? yes, the standard sample/annotate support was already in perf jirka
