perf trace: Allow dumping a BPF map after setting up BPF events
Initial use case:
Dumping the maps setup by tools/perf/examples/bpf/augmented_raw_syscalls.c,
which so far are just booleans, showing just non-zeroed entries:
# cat ~/.perfconfig
[llvm]
dump-obj = true
clang-opt = -g
[trace]
#add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
add_events = /wb/augmented_raw_syscalls.o
$ date
Tue Feb 19 16:29:33 -03 2019
$ ls -la /wb/augmented_raw_syscalls.o
-rwxr-xr-x. 1 root root 14048 Jan 24 12:09 /wb/augmented_raw_syscalls.o
$ file /wb/augmented_raw_syscalls.o
/wb/augmented_raw_syscalls.o: ELF 64-bit LSB relocatable, eBPF, version 1 (SYSV), with debug_info, not stripped
$
# trace -e recvmmsg,sendmmsg --map-dump foobar
ERROR: BPF map "foobar" not found
# trace -e recvmmsg,sendmmsg --map-dump filtered_pids
ERROR: BPF map "filtered_pids" not found
# trace -e recvmmsg,sendmmsg --map-dump pids_filtered
[2583] = 1,
[2267] = 1,
^Z
[1]+ Stopped trace -e recvmmsg,sendmmsg --map-dump pids_filtered
# pidof trace
2267
# ps ax|grep gnome-terminal|grep -v grep
2583 ? Ssl 58:33 /usr/libexec/gnome-terminal-server
^C
# trace -e recvmmsg,sendmmsg --map-dump syscalls
[299] = 1,
[307] = 1,
^C
# grep x64_recvmmsg arch/x86/entry/syscalls/syscall_64.tbl
299 64 recvmmsg __x64_sys_recvmmsg
# grep x64_sendmmsg arch/x86/entry/syscalls/syscall_64.tbl
307 64 sendmmsg __x64_sys_sendmmsg
#
Next step probably will be something like 'perf stat's --interval-print and
--interval-clear.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lkml.kernel.org/n/tip-ztxj25rtx37ixo9cfajt8ocy@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2 files changed
