Hi, On 2022-07-03 13:54:41 +0200, Sedat Dilek wrote: > Andres, you have some test-cases how you verified the built perf is OK? I ran an intentionally expensive workload, monitored it with bpftrace, then took a perf profile. Then annotated the bpf "function" and verified it looked the same before / after, using a perf built in a container (and thus compiling). Similar with bpftool, I dumped a jited program with a bpftool built with / without the patches (inside the container using nsenter for the version without the patches, so I could build it, using nsenter -t $pid -m -p) and compared both the json and non-json output before / after. V=4; nsenter -t 847325 -m -p /usr/src/linux/tools/bpf/bpftool/bpftool -j -d prog dump jited id 22 > /tmp/22.jit.json.$V; nsenter -t 847325 -m -p /usr/src/linux/tools/bpf/bpftool/bpftool -d prog dump jited id 22 > /tmp/22.jit.txt.$V and then diffed the results. bpf_jit_disasm was harder, because bpf_jit_enable = 2 is broken currently. So I gathered output in a VM from an older kernel, and used bpf_jit_disasm -f ... before / after the patches. Greetings, Andres Freund
