diff --git a/test/README.md b/test/README.md
index 680f9bf9a..1cf22cb64 100644
--- a/test/README.md
+++ b/test/README.md
@@ -176,6 +176,26 @@ gdb /home/example/bitcoind <pid>
Note: gdb attach step may require `sudo`
+##### Profiling
+
+An easy way to profile node performance during functional tests is provided
+for Linux platforms using `perf`.
+
+Perf will sample the running node and will generate profile data in the node's
+datadir. The profile data can then be presented using `perf report` or a graphical
+tool like [hotspot](https://github.com/KDAB/hotspot).
+
+To generate a profile during test suite runs, use the `--perf` flag.
+
+To see render the output to text, run
+
+```sh
+perf report -i /path/to/datadir/send-big-msgs.perf.data.xxxx --stdio | c++filt | less
+```
+
+For ways to generate more granular profiles, see the README in
+[test/functional](/test/functional).
+
### Util tests
Util tests can be run locally by running `test/util/bitcoin-util-test.py`.
diff --git a/test/functional/README.md b/test/functional/README.md
index d40052ac9..711151d60 100644
--- a/test/functional/README.md
+++ b/test/functional/README.md
@@ -118,3 +118,36 @@ Helpers for script.py
#### [test_framework/blocktools.py](test_framework/blocktools.py)
Helper functions for creating blocks and transactions.
+
+### Benchmarking with perf
+
+An easy way to profile node performance during functional tests is provided
+for Linux platforms using `perf`.
+
+Perf will sample the running node and will generate profile data in the node's
+datadir. The profile data can then be presented using `perf report` or a graphical
+tool like [hotspot](https://github.com/KDAB/hotspot).
+
+There are two ways of invoking perf: one is to use the `--perf` flag when
+running tests, which will profile each node during the entire test run: perf
+begins to profile when the node starts and ends when it shuts down. The other
+way is the use the `profile_with_perf` context manager, e.g.
+
+```python
+with node.profile_with_perf("send-big-msgs"):
+ # Perform activity on the node you're interested in profiling, e.g.:
+ for _ in range(10000):
+ node.p2p.send_message(some_large_message)
+```
+
+To see useful textual output, run
+
+```sh
+perf report -i /path/to/datadir/send-big-msgs.perf.data.xxxx --stdio | c++filt | less
+```
+
+#### See also:
+
+- [Installing perf](https://askubuntu.com/q/50145)
+- [Perf examples](http://www.brendangregg.com/perf.html)
+- [Hotspot](https://github.com/KDAB/hotspot): a GUI for perf output analysis
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
index 352fa32b5..240d9ce87 100755
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -128,6 +128,8 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
help="Attach a python debugger if test fails")
parser.add_argument("--usecli", dest="usecli", default=False, action="store_true",
help="use bitcoin-cli instead of RPC for all commands")
+ parser.add_argument("--perf", dest="perf", default=False, action="store_true",
+ help="profile running nodes with perf for the duration of the test")
self.add_options(parser)
self.options = parser.parse_args()
@@ -201,11 +203,20 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
node.cleanup_on_exit = False
self.log.info("Note: bitcoinds were not stopped and may still be running")
- if not self.options.nocleanup and not self.options.noshutdown and success != TestStatus.FAILED:
+ should_clean_up = (
+ not self.options.nocleanup and
+ not self.options.noshutdown and
+ success != TestStatus.FAILED and
+ not self.options.perf
+ )
+ if should_clean_up:
self.log.info("Cleaning up {} on exit".format(self.options.tmpdir))
cleanup_tree_on_exit = True
+ elif self.options.perf:
+ self.log.warning("Not cleaning up dir {} due to perf data".format(self.options.tmpdir))
+ cleanup_tree_on_exit = False
else:
- self.log.warning("Not cleaning up dir %s" % self.options.tmpdir)
+ self.log.warning("Not cleaning up dir {}".format(self.options.tmpdir))
cleanup_tree_on_exit = False
if success == TestStatus.PASSED:
@@ -309,6 +320,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
extra_conf=extra_confs[i],
extra_args=extra_args[i],
use_cli=self.options.usecli,
+ start_perf=self.options.perf,
))
def start_node(self, i, *args, **kwargs):
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 031a8824b..14d37e722 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -18,6 +18,8 @@ import tempfile
import time
import urllib.parse
import collections
+import shlex
+import sys
from .authproxy import JSONRPCException
from .util import (
@@ -59,7 +61,13 @@ class TestNode():
To make things easier for the test writer, any unrecognised messages will
be dispatched to the RPC connection."""
- def __init__(self, i, datadir, *, rpchost, timewait, bitcoind, bitcoin_cli, mocktime, coverage_dir, extra_conf=None, extra_args=None, use_cli=False):
+ def __init__(self, i, datadir, *, rpchost, timewait, bitcoind, bitcoin_cli, mocktime, coverage_dir, extra_conf=None, extra_args=None, use_cli=False, start_perf=False):
+ """
+ Kwargs:
+ start_perf (bool): If True, begin profiling the node with `perf` as soon as
+ the node starts.
+ """
+
self.index = i
self.datadir = datadir
self.stdout_dir = os.path.join(self.datadir, "stdout")
@@ -87,6 +95,7 @@ class TestNode():
self.cli = TestNodeCLI(bitcoin_cli, self.datadir)
self.use_cli = use_cli
+ self.start_perf = start_perf
self.running = False
self.process = None
@@ -95,6 +104,8 @@ class TestNode():
self.url = None
self.log = logging.getLogger('TestFramework.node%d' % i)
self.cleanup_on_exit = True # Whether to kill the node when this object goes away
+ # Cache perf subprocesses here by their data output filename.
+ self.perf_subprocesses = {}
self.p2ps = []
@@ -186,6 +197,9 @@ class TestNode():
self.running = True
self.log.debug("bitcoind started, waiting for RPC to come up")
+ if self.start_perf:
+ self._start_perf()
+
def wait_for_rpc_connection(self):
"""Sets up an RPC connection to the bitcoind process. Returns False if unable to connect."""
# Poll at a rate of four times per second
@@ -238,6 +252,10 @@ class TestNode():
except http.client.CannotSendRequest:
self.log.exception("Unable to stop node.")
+ # If there are any running perf processes, stop them.
+ for profile_name in tuple(self.perf_subprocesses.keys()):
+ self._stop_perf(profile_name)
+
# Check that stderr is as expected
self.stderr.seek(0)
stderr = self.stderr.read().decode('utf-8').strip()
@@ -317,6 +335,84 @@ class TestNode():
increase_allowed * 100, before_memory_usage, after_memory_usage,
perc_increase_memory_usage * 100))
+ @contextlib.contextmanager
+ def profile_with_perf(self, profile_name):
+ """
+ Context manager that allows easy profiling of node activity using `perf`.
+
+ See `test/functional/README.md` for details on perf usage.
+
+ Args:
+ profile_name (str): This string will be appended to the
+ profile data filename generated by perf.
+ """
+ subp = self._start_perf(profile_name)
+
+ yield
+
+ if subp:
+ self._stop_perf(profile_name)
+
+ def _start_perf(self, profile_name=None):
+ """Start a perf process to profile this node.
+
+ Returns the subprocess running perf."""
+ subp = None
+
+ def test_success(cmd):
+ return subprocess.call(
+ # shell=True required for pipe use below
+ cmd, shell=True,
+ stderr=subprocess.DEVNULL, stdout=subprocess.DEVNULL) == 0
+
+ if not sys.platform.startswith('linux'):
+ self.log.warning("Can't profile with perf; only availabe on Linux platforms")
+ return None
+
+ if not test_success('which perf'):
+ self.log.warning("Can't profile with perf; must install perf-tools")
+ return None
+
+ if not test_success('readelf -S {} | grep .debug_str'.format(shlex.quote(self.binary))):
+ self.log.warning(
+ "perf output won't be very useful without debug symbols compiled into bitcoind")
+
+ output_path = tempfile.NamedTemporaryFile(
+ dir=self.datadir,
+ prefix="{}.perf.data.".format(profile_name or 'test'),
+ delete=False,
+ ).name
+
+ cmd = [
+ 'perf', 'record',
+ '-g', # Record the callgraph.
+ '--call-graph', 'dwarf', # Compatibility for gcc's --fomit-frame-pointer.
+ '-F', '101', # Sampling frequency in Hz.
+ '-p', str(self.process.pid),
+ '-o', output_path,
+ ]
+ subp = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+ self.perf_subprocesses[profile_name] = subp
+
+ return subp
+
+ def _stop_perf(self, profile_name):
+ """Stop (and pop) a perf subprocess."""
+ subp = self.perf_subprocesses.pop(profile_name)
+ output_path = subp.args[subp.args.index('-o') + 1]
+
+ subp.terminate()
+ subp.wait(timeout=10)
+
+ stderr = subp.stderr.read().decode()
+ if 'Consider tweaking /proc/sys/kernel/perf_event_paranoid' in stderr:
+ self.log.warning(
+ "perf couldn't collect data! Try "
+ "'sudo sysctl -w kernel.perf_event_paranoid=-1'")
+ else:
+ report_cmd = "perf report -i {}".format(output_path)
+ self.log.info("See perf output by running '{}'".format(report_cmd))
+
def assert_start_raises_init_error(self, extra_args=None, expected_msg=None, match=ErrorMatch.FULL_TEXT, *args, **kwargs):
"""Attempt to start the node and expect it to raise an error.
diff --git a/test/lint/lint-python-dead-code.sh b/test/lint/lint-python-dead-code.sh
index 1b897cd13..863caa9d5 100755
--- a/test/lint/lint-python-dead-code.sh
+++ b/test/lint/lint-python-dead-code.sh
@@ -15,5 +15,5 @@ fi
vulture \
--min-confidence 60 \
- --ignore-names "argtypes,connection_lost,connection_made,converter,data_received,daemon,errcheck,get_ecdh_key,get_privkey,is_compressed,is_fullyvalid,msg_generic,on_*,optionxform,restype,set_privkey" \
+ --ignore-names "argtypes,connection_lost,connection_made,converter,data_received,daemon,errcheck,get_ecdh_key,get_privkey,is_compressed,is_fullyvalid,msg_generic,on_*,optionxform,restype,set_privkey,profile_with_perf" \
$(git ls-files -- "*.py" ":(exclude)contrib/" ":(exclude)test/functional/data/invalid_txs.py")