Display list construction is the biggest bottleneck in our painting code. Luckily, the Layout team is about to enable "retained display lists" which should give us major performance improvements. The idea is that after the initial pageload, the display list can be incrementally modified every frame rather than rebuilt from scratch. Unfortunately Talos's pageload tests won't capture these changes - we won't see any benefit, and we won't be able to see whether the new algorithm regresses in the future. We do have Telemetry probes, and we expect those numbers to move significantly. But since this project is a big deal we should have at least one performance test for it.

try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=5b050af410e795d33c8186fabca1e3ad92522de7

Try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=8af7c706722253d1796521cdab5e06590a46cbb7 I added the test to g2 since that seems to run on Windows. The average runtime looks to be 20 seconds, and it runs for 5 iterations.

Comment on attachment 8922216 [details] [diff] [review] patch Review of attachment 8922216 [details] [diff] [review]: ----------------------------------------------------------------- Looks good from the test perspective, should be stressing the display list building pretty extensively. Great to have coverage of this in the tree!

as a note, this looks good, I did some retriggers and am waiting for results to come in, there is a large backlog on windows7 and linux right now. I would prefer to put this test in 'g4' as that is a job that runs faster than 'g2'.

Comment on attachment 8922216 [details] [diff] [review] patch Review of attachment 8922216 [details] [diff] [review]: ----------------------------------------------------------------- ::: testing/talos/talos.json @@ +30,5 @@ > "talos_options": ["--disable-stylo"], > "pagesets_name": "tp5n.zip" > }, > "g2-e10s": { > + "tests": ["damp", "tps", "displaylist_mutate"], please put this in g4-e10s as that has a much shorter runtime than g2. The retriggers and results look good!

Pushed by danderson@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/9421a340f682 Add a Talos test for displaylist mutation. (bug 1411804, r=jmaher, r=mattwoodrow)

Pushed by archaeopteryx@coole-files.de: https://hg.mozilla.org/integration/mozilla-inbound/rev/39ad112131fe Add a Talos test for displaylist mutation. . Follow-up: Add empty line to fix linting issue. r=me DONTBUILD

Backed out for failing eslint in testing/talos/talos/tests/layout/benchmarks/displaylist_mutate.html: https://hg.mozilla.org/integration/mozilla-inbound/rev/c2dc77f89b472c80c6cf3d15a5cedfda4df3de25 Push with failures (the fix for the flake8 has been folded into the backout): https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&revision=9421a340f6821851da7f72c3ff18fc306a1d4aa1&filter-resultStatus=usercancel&filter-resultStatus=runnable&filter-resultStatus=retry&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception Failure log: https://treeherder.mozilla.org/logviewer.html#?job_id=140286005&repo=mozilla-inbound TEST-UNEXPECTED-ERROR | /builds/worker/checkouts/gecko/testing/talos/talos/tests/layout/benchmarks/displaylist_mutate.html:26:5 | 'i' is already defined. (no-redeclare) TEST-UNEXPECTED-ERROR | /builds/worker/checkouts/gecko/testing/talos/talos/tests/layout/benchmarks/displaylist_mutate.html:34:8 | Infix operators must be spaced. (space-infix-ops) TEST-UNEXPECTED-ERROR | /builds/worker/checkouts/gecko/testing/talos/talos/tests/layout/benchmarks/displaylist_mutate.html:36:15 | use performance.now() instead of new Date() for timing measurements (mozilla/avoid-Date-timing) TEST-UNEXPECTED-ERROR | /builds/worker/checkouts/gecko/testing/talos/talos/tests/layout/benchmarks/displaylist_mutate.html:55:56 | Strings must use doublequote. (quotes) TEST-UNEXPECTED-ERROR | /builds/worker/checkouts/gecko/testing/talos/talos/tests/layout/benchmarks/displaylist_mutate.html:62:13 | use performance.now() instead of new Date() for timing measurements (mozilla/avoid-Date-timing)

Pushed by danderson@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/d7a32fbcb477 Add a Talos test for displaylist mutation. (bug 1411804, r=jmaher, r=mattwoodrow)

Backed out in https://hg.mozilla.org/integration/mozilla-inbound/rev/60b780a847f8 for failing eslint, https://treeherder.mozilla.org/logviewer.html#?job_id=140632178&repo=mozilla-inbound

Pushed by danderson@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/f8eb20e6a5e5 Add a Talos test for displaylist mutation. (bug 1411804, r=jmaher, r=mattwoodrow)