Mercurial > hg
view contrib/catapipe.py @ 44363:f7459da77f23
nodemap: introduce an option to use mmap to read the nodemap mapping
The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.
This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).
Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:
Before:
* do not use the persistent nodemap
* use the CPython implementation of the index for nodemap
* use mmapping of the changelog index
After:
* use the MixedIndex Rust code, with the NodeTree object for nodemap access
(still in review)
* use the persistent nodemap data from disk
* access the persistent nodemap data through mmap
* use mmapping of the changelog index
The persistent nodemap greatly speed up most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.
Here are some numbers (in seconds) for the reference copy of mozilla-try:
Revset Before After abs-change speedup
-10000: 0.004622 0.005532 0.000910 × 0.83
-10: 0.000050 0.000132 0.000082 × 0.37
tip 0.000052 0.000085 0.000033 × 0.61
0 + (-10000:) 0.028222 0.005337 -0.022885 × 5.29
0 0.023521 0.000084 -0.023437 × 280.01
(-10000:) + 0 0.235539 0.005308 -0.230231 × 44.37
(-10:) + :9 0.232883 0.000180 -0.232703 ×1293.79
(-10000:) + (:99) 0.238735 0.005358 -0.233377 × 44.55
:99 + (-10000:) 0.317942 0.005593 -0.312349 × 56.84
:9 + (-10:) 0.313372 0.000179 -0.313193 ×1750.68
:9 0.316450 0.000143 -0.316307 ×2212.93
On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.
Here are some numbers (in seconds) for the reference copy of mercurial:
Revset Before After abs-change speedup
-10: 0.000065 0.000097 0.000032 × 0.67
tip 0.000063 0.000078 0.000015 × 0.80
0 0.000561 0.000079 -0.000482 × 7.10
-10000: 0.004609 0.003648 -0.000961 × 1.26
0 + (-10000:) 0.005023 0.003715 -0.001307 × 1.35
(-10:) + :9 0.002187 0.000108 -0.002079 ×20.25
(-10000:) + 0 0.006252 0.003716 -0.002536 × 1.68
(-10000:) + (:99) 0.006367 0.003707 -0.002660 × 1.71
:9 + (-10:) 0.003846 0.000110 -0.003736 ×34.96
:9 0.003854 0.000099 -0.003755 ×38.92
:99 + (-10000:) 0.007644 0.003778 -0.003866 × 2.02
Differential Revision: https://phab.mercurial-scm.org/D7894
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 11 Feb 2020 11:18:52 +0100 |
parents | 2372284d9457 |
children | 6000f5b25c9b |
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#!/usr/bin/env python3 # # Copyright 2018 Google LLC. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Tool read primitive events from a pipe to produce a catapult trace. Usage: Terminal 1: $ catapipe.py /tmp/mypipe /tmp/trace.json Terminal 2: $ HGCATAPULTSERVERPIPE=/tmp/mypipe hg root <ctrl-c catapipe.py in Terminal 1> $ catapult/tracing/bin/trace2html /tmp/trace.json # produce /tmp/trace.html <open trace.html in your browser of choice; the WASD keys are very useful> (catapult is located at https://github.com/catapult-project/catapult) For now the event stream supports START $SESSIONID ... and END $SESSIONID ... events. Everything after the SESSIONID (which must not contain spaces) is used as a label for the event. Events are timestamped as of when they arrive in this process and are then used to produce catapult traces that can be loaded in Chrome's about:tracing utility. It's important that the event stream *into* this process stay simple, because we have to emit it from the shell scripts produced by run-tests.py. Typically you'll want to place the path to the named pipe in the HGCATAPULTSERVERPIPE environment variable, which both run-tests and hg understand. To trace *only* run-tests, use HGTESTCATAPULTSERVERPIPE instead. """ from __future__ import absolute_import, print_function import argparse import json import os import timeit _TYPEMAP = { 'START': 'B', 'END': 'E', 'COUNTER': 'C', } _threadmap = {} # Timeit already contains the whole logic about which timer to use based on # Python version and OS timer = timeit.default_timer def main(): parser = argparse.ArgumentParser() parser.add_argument( 'pipe', type=str, nargs=1, help='Path of named pipe to create and listen on.', ) parser.add_argument( 'output', default='trace.json', type=str, nargs='?', help='Path of json file to create where the traces ' 'will be stored.', ) parser.add_argument( '--debug', default=False, action='store_true', help='Print useful debug messages', ) args = parser.parse_args() fn = args.pipe[0] os.mkfifo(fn) try: with open(fn) as f, open(args.output, 'w') as out: out.write('[\n') start = timer() while True: ev = f.readline().strip() if not ev: continue now = timer() if args.debug: print(ev) verb, session, label = ev.split(' ', 2) if session not in _threadmap: _threadmap[session] = len(_threadmap) if verb == 'COUNTER': amount, label = label.split(' ', 1) payload_args = {'value': int(amount)} else: payload_args = {} pid = _threadmap[session] ts_micros = (now - start) * 1000000 out.write( json.dumps( { "name": label, "cat": "misc", "ph": _TYPEMAP[verb], "ts": ts_micros, "pid": pid, "tid": 1, "args": payload_args, } ) ) out.write(',\n') finally: os.unlink(fn) if __name__ == '__main__': main()