perf bpf: Save bpf_prog_info information as headers to perf.data
This patch enables perf-record to save bpf_prog_info information as headers to perf.data. A new header type HEADER_BPF_PROG_INFO is introduced for this data. Committer testing: As root, being on the kernel sources top level directory, run: # perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c -e *msg Just to compile and load a BPF program that attaches to the raw_syscalls:sys_{enter,exit} tracepoints to trace the syscalls ending in "msg" (recvmsg, sendmsg, recvmmsg, sendmmsg, etc). Then do a systemwide perf record session for a few seconds: # perf record -a sleep 2s Then look at: # perf report --header-only | grep -i bpf # bpf_prog_info of id 13 # bpf_prog_info of id 14 # bpf_prog_info of id 15 # bpf_prog_info of id 16 # bpf_prog_info of id 17 # bpf_prog_info of id 18 # bpf_prog_info of id 21 # bpf_prog_info of id 22 # bpf_prog_info of id 208 # bpf_prog_info of id 209 # We need to show more info about these programs, like bpftool does for the ones running on the system, i.e. 'perf record/perf report' become a way of saving the BPF state in a machine to then analyse on another, together with all the other information that is already saved in the perf.data header: # perf report --header-only # ======== # captured on : Tue Mar 12 11:42:13 2019 # header version : 1 # data offset : 296 # data size : 16294184 # feat offset : 16294480 # hostname : quaco # os release : 5.0.0+ # perf version : 5.0.gd783c8 # arch : x86_64 # nrcpus online : 8 # nrcpus avail : 8 # cpudesc : Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz # cpuid : GenuineIntel,6,142,10 # total memory : 24555720 kB # cmdline : /home/acme/bin/perf (deleted) record -a # event : name = cycles:ppp, , id = { 3190123, 3190124, 3190125, 31901264 , 3190127, 3190128, 3190129, 3190130 }, size = 112, { sample_period, sample_freq } = 4000, sample_type = IP|TID|TIME|CPU|PERIOD, read_format = ID, disabled = 1, inherit = 1, mmap = 1, comm = 1, freq = 1, task = 1, precise_ip = 3, sample_id_all = 1, exclude_guest = 1, mmap2 = 1, comm_exec = 1 # CPU_TOPOLOGY info available, use -I to display # NUMA_TOPOLOGY info available, use -I to display # pmu mappings: intel_pt = 8, software = 1, power = 11, uprobe = 7, uncore_imc = 12, cpu = 4, cstate_core = 18, uncore_cbox_2 = 15, breakpoint = 5, uncore_cbox_0 = 13, tracepoint = 2, cstate_pkg = 19, uncore_arb = 17, kprobe = 6, i915 = 10, msr = 9, uncore_cbox_3 = 16, uncore_cbox_1 = 14 # CACHE info available, use -I to display # time of first sample : 116392.441701 # time of last sample : 116400.932584 # sample duration : 8490.883 ms # MEM_TOPOLOGY info available, use -I to display # bpf_prog_info of id 13 # bpf_prog_info of id 14 # bpf_prog_info of id 15 # bpf_prog_info of id 16 # bpf_prog_info of id 17 # bpf_prog_info of id 18 # bpf_prog_info of id 21 # bpf_prog_info of id 22 # bpf_prog_info of id 208 # bpf_prog_info of id 209 # missing features: TRACING_DATA BRANCH_STACK GROUP_DESC AUXTRACE STAT CLOCKID DIR_FORMAT # ======== # Committer notes: We can't use the libbpf unconditionally, as the build may have been with NO_LIBBPF, when we end up with linking errors, so provide dummy {process,write}_bpf_prog_info() wrapped by HAVE_LIBBPF_SUPPORT for that case. Printing are not affected by this, so can continue as is. Signed-off-by:Song Liu <songliubraving@fb.com> Reviewed-by:
Jiri Olsa <jolsa@kernel.org> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: kernel-team@fb.com Link: http://lkml.kernel.org/r/20190312053051.2690567-8-songliubraving@fb.com Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
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