Mercurial > hg
view mercurial/node.py @ 35599:af25237be091
perf: add threading capability to perfbdiff
Since we are releasing the GIL during diffing, it is interesting to see how a
thread pool would perform on diffing. We add a new `--threads` argument to
commands. Synchronizing the thread pool is a bit complex because we want to be
able to reuse it from one run to another.
On my computer (i7 with 4 cores + hyperthreading), I get the following data for
about 12000 revisions:
threads wall comb wall gain comb overhead
none 31.596715 31.59 0.00% 0.00%
1 31.621228 31.62 -0.08% 0.09%
2 16.406202 32.8 48.08% 3.83%
3 11.598334 34.76 63.29% 10.03%
4 9.205421 36.77 70.87% 16.40%
5 8.517604 42.51 73.04% 34.57%
6 7.94645 47.58 74.85% 50.62%
7 7.434972 51.92 76.47% 64.36%
8 7.070638 55.34 77.62% 75.18%
Compared to the feature disabled (threads=0), the overhead is negligible with
the threading code (threads=1), and the gain is already 48% with two threads.
author | Boris Feld <boris.feld@octobus.net> |
---|---|
date | Sun, 17 Dec 2017 04:31:27 +0100 |
parents | af854b1b36f8 |
children | f574cc00831a |
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# node.py - basic nodeid manipulation for mercurial # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import binascii # This ugly style has a noticeable effect in manifest parsing hex = binascii.hexlify bin = binascii.unhexlify nullrev = -1 nullid = b"\0" * 20 nullhex = hex(nullid) # Phony node value to stand-in for new files in some uses of # manifests. newnodeid = '!' * 20 addednodeid = ('0' * 15) + 'added' modifiednodeid = ('0' * 12) + 'modified' wdirnodes = {newnodeid, addednodeid, modifiednodeid} # pseudo identifiers for working directory # (they are experimental, so don't add too many dependencies on them) wdirrev = 0x7fffffff wdirid = b"\xff" * 20 wdirhex = hex(wdirid) def short(node): return hex(node[:6])