From: Jakub Kicinski kuba@kernel.org
bpftrace is very useful for low level driver testing. perf or trace-cmd would also do for collecting data from tracepoints, but they require much more post-processing.
Add a wrapper for running bpftrace and sanitizing its output. bpftrace has JSON output, which is great, but it prints loose objects and in a slightly inconvenient format. We have to read the objects line by line, and while at it return them indexed by the map name.
Signed-off-by: Jakub Kicinski kuba@kernel.org Reviewed-by: Breno Leitao leitao@debian.org Signed-off-by: Breno Leitao leitao@debian.org --- .../selftests/drivers/net/lib/py/__init__.py | 3 +- tools/testing/selftests/net/lib/py/utils.py | 33 ++++++++++++++++++++++ 2 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/drivers/net/lib/py/__init__.py b/tools/testing/selftests/drivers/net/lib/py/__init__.py index 9ed1d8f70524a..98829a0f7a02c 100644 --- a/tools/testing/selftests/drivers/net/lib/py/__init__.py +++ b/tools/testing/selftests/drivers/net/lib/py/__init__.py @@ -14,7 +14,8 @@ try: from net.lib.py import EthtoolFamily, NetdevFamily, NetshaperFamily, \ NlError, RtnlFamily from net.lib.py import CmdExitFailure - from net.lib.py import bkg, cmd, defer, ethtool, fd_read_timeout, ip, \ + from net.lib.py import bkg, cmd, bpftrace, defer, ethtool, \ + fd_read_timeout, ip, \ rand_port, tool, wait_port_listen from net.lib.py import fd_read_timeout from net.lib.py import KsftSkipEx, KsftFailEx, KsftXfailEx diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py index 34470d65d871a..760ccf6fccccc 100644 --- a/tools/testing/selftests/net/lib/py/utils.py +++ b/tools/testing/selftests/net/lib/py/utils.py @@ -185,6 +185,39 @@ def ethtool(args, json=None, ns=None, host=None): return tool('ethtool', args, json=json, ns=ns, host=host)
+def bpftrace(expr, json=None, ns=None, host=None, timeout=None): + """ + Run bpftrace and return map data (if json=True). + The output of bpftrace is inconvenient, so the helper converts + to a dict indexed by map name, e.g.: + { + "@": { ... }, + "@map2": { ... }, + } + """ + cmd_arr = ['bpftrace'] + # Throw in --quiet if json, otherwise the output has two objects + if json: + cmd_arr += ['-f', 'json', '-q'] + if timeout: + expr += ' interval:s:' + str(timeout) + ' { exit(); }' + cmd_arr += ['-e', expr] + cmd_obj = cmd(cmd_arr, ns=ns, host=host, shell=False) + if json: + # bpftrace prints objects as lines + ret = {} + for l in cmd_obj.stdout.split('\n'): + if not l.strip(): + continue + one = _json.loads(l) + if one.get('type') != 'map': + continue + for k, v in one["data"].items(): + ret[k] = v + return ret + return cmd_obj + + def rand_port(type=socket.SOCK_STREAM): """ Get a random unprivileged port.