commit | 5e3b0aa36d05e39f840e2725fe9d9e9bc654c578 | [log] [tgz] |
---|---|---|
author | Steinar H. Gunderson <sesse@chromium.org> | Mon Sep 25 12:40:23 2023 |
committer | Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> | Mon Sep 25 12:58:45 2023 |
tree | 87401428bc0b829ffb3d0ee44c83564182dbe847 | |
parent | e053db4bf52bdf84cf2c38e8edc3245807c83c17 [diff] |
Switch RuleMap to a custom hash table. A significant part of style (~6%) is doing lookups in RuleMaps, specifically in AtomicString-indexed hash tables. These currently use WTF::HashTable, but we can do better with a custom hash table implementation. Thus, we implement RobinHoodMap, a lookup-optimized variant with higher load factor and thus tighter memory footprint. One direct consequence of this is less RAM usage; e.g. Social1 reports ~460 kB less PartitionAlloc memory allocated (most subtests have smaller hash tables, though, since they have fewer rules). But we also get less cache pressure. The exact result depends on the CPU; smaller/slower caches give more gains, less sophisticated branch predictors give less gains. In general, most seem to be around neutral, but Intel CPUs give a fairly good gain. Inserts are slightly slower and lookups are faster, so repeated style application should get larger gains. Of course, in the style perftest, we have the cache all to ourselves, so it will tend to underestimate these effects somewhat. Style perftest (Alder Lake P-cores, LTO but no PGO): Initial style (µs) Before After Perf 95% CI (BCa) =================== ========= ========= ======= ================= ECommerce 4491 4484 +0.1% [ -0.6%, +0.8%] Encyclopedia 40679 39868 +2.0% [ +1.1%, +2.9%] Extension 53970 53971 -0.0% [ -0.8%, +0.7%] News 19728 19325 +2.1% [ +0.9%, +3.2%] Search 6316 6176 +2.3% [ +1.1%, +3.4%] Social1 11547 11753 -1.8% [ -2.8%, -0.7%] Social2 7383 7281 +1.4% [ +0.4%, +2.3%] Sports 20644 20580 +0.3% [ -0.8%, +1.4%] Video 16020 16064 -0.3% [ -1.1%, +0.5%] Geometric mean +0.7% [ +0.1%, +1.2%] Recalc style (µs) Before After Perf 95% CI (BCa) =================== ========= ========= ======= ================= ECommerce 5011 4958 +1.1% [ +0.3%, +1.8%] Encyclopedia 32407 31336 +3.4% [ +2.6%, +4.3%] Extension 49217 48970 +0.5% [ -0.3%, +1.2%] News 15065 14569 +3.4% [ +2.3%, +4.4%] Search 2911 2771 +5.0% [ +4.3%, +5.9%] Social1 7417 7271 +2.0% [ +0.8%, +3.0%] Social2 5634 5548 +1.5% [ +0.6%, +2.4%] Sports 11345 11040 +2.8% [ +1.9%, +3.6%] Video 10659 10381 +2.7% [ +1.8%, +3.6%] Geometric mean +2.5% [ +1.9%, +3.0%] Change-Id: I3b25f24d0595b21ad5d5e354e2c03a390bddc5aa Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4866725 Commit-Queue: Steinar H Gunderson <sesse@chromium.org> Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org> Cr-Commit-Position: refs/heads/main@{#1200933}
The web-platform-tests Project is a cross-browser test suite for the Web-platform stack. Writing tests in a way that allows them to be run in all browsers gives browser projects confidence that they are shipping software that is compatible with other implementations, and that later implementations will be compatible with their implementations. This in turn gives Web authors/developers confidence that they can actually rely on the Web platform to deliver on the promise of working across browsers and devices without needing extra layers of abstraction to paper over the gaps left by specification editors and implementors.
The most important sources of information and activity are:
wpt:matrix.org
matrix channel; includes participants located around the world, but busiest during the European working day.If you'd like clarification about anything, don't hesitate to ask in the chat room or on the mailing list.
Clone or otherwise get https://github.com/web-platform-tests/wpt.
Note: because of the frequent creation and deletion of branches in this repo, it is recommended to “prune” stale branches when fetching updates, i.e. use git pull --prune
(or git fetch -p && git merge
).
See the documentation website and in particular the system setup for running tests locally.
The wpt
command provides a frontend to a variety of tools for working with and running web-platform-tests. Some of the most useful commands are:
wpt serve
- For starting the wpt http serverwpt run
- For running tests in a browserwpt lint
- For running the lint against all testswpt manifest
- For updating or generating a MANIFEST.json
test manifestwpt install
- For installing the latest release of a browser or webdriver server on the local machine.wpt serve-wave
- For starting the wpt http server and the WAVE test runner. For more details on how to use the WAVE test runner see the documentation.On Windows wpt
commands must be prefixed with python
or the path to the python binary (if python
is not in your %PATH%
).
python wpt [command]
Alternatively, you may also use Bash on Ubuntu on Windows in the Windows 10 Anniversary Update build, then access your windows partition from there to launch wpt
commands.
Please make sure git and your text editor do not automatically convert line endings, as it will cause lint errors. For git, please set git config core.autocrlf false
in your working tree.
The master branch is automatically synced to wpt.live and w3c-test.org.
Save the Web, Write Some Tests!
Absolutely everyone is welcome to contribute to test development. No test is too small or too simple, especially if it corresponds to something for which you've noted an interoperability bug in a browser.
The way to contribute is just as usual:
git checkout -b topic
../wpt lint
as described above.If you spot an issue with a test and are not comfortable providing a pull request per above to fix it, please file a new issue. Thank you!