From https://bugs.webkit.org/show_bug.cgi?id=187866 Truitt Savell 2018-07-30 10:27:14 PDT It looks like there are three tests on High Sierra WK1 that are continuing to fail consistently after https://trac.webkit.org/changeset/234330/webkit. The tests are flakey on other WK1 release platforms. Tests: legacy-animation-engine/compositing/backing/transform-transition-from-outside-view.html legacy-animation-engine/compositing/geometry/limit-layer-bounds-opacity-transition.html legacy-animation-engine/compositing/layer-creation/animation-overlap-with-children.html Test History https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=legacy-animation-engine%2Fcompositing%2Fbacking%2Ftransform-transition-from-outside-view.html%20legacy-animation-engine%2Fcompositing%2Fgeometry%2Flimit-layer-bounds-opacity-transition.html%20legacy-animation-engine%2Fcompositing%2Flayer-creation%2Fanimation-overlap-with-children.html Text Diffs: https://build.webkit.org/results/Apple%20High%20Sierra%20Release%20WK1%20(Tests)/r234363%20(7001)/legacy-animation-engine/compositing/backing/transform-transition-from-outside-view-diff.txt https://build.webkit.org/results/Apple%20High%20Sierra%20Release%20WK1%20(Tests)/r234363%20(7001)/legacy-animation-engine/compositing/geometry/limit-layer-bounds-opacity-transition-diff.txt https://build.webkit.org/results/Apple%20High%20Sierra%20Release%20WK1%20(Tests)/r234363%20(7001)/legacy-animation-engine/compositing/layer-creation/animation-overlap-with-children-diff.txt
I reproduces two flakes and am fixing in bug 188356, but I could not reproduce all of these.
<rdar://problem/42986633>
I can only reproduce flakiness with: legacy-animation-engine/animations/needs-layout.html failed unexpectedly (reference mismatch) legacy-animation-engine/animations/trigger-container-scroll-empty.html failed unexpectedly (text diff)
Created attachment 346717 [details] Repro Test List Here is a reliable repro of the Three tests that are failing. A state is being set and this list order reliably reproduces the failure. I ran this list of tests using: run-webkit-tests --test-list DIRECTORY_OF_TEST_LIST_FILE --child-processes 1 -1 I am going to try and bisect the list and see if I can get a better idea of what's causing this.
These tests are causing the failures: js/slow-stress/Int32Array-alloc-large-long-lived.html js/slow-stress/Int32Array-alloc-huge.html js/slow-stress/Int32Array-alloc-huge-long-lived.html legacy-animation-engine/compositing/backing/transform-transition-from-outside-view.html legacy-animation-engine/compositing/geometry/limit-layer-bounds-opacity-transition.html legacy-animation-engine/compositing/layer-creation/animation-overlap-with-children.html Running these tests together causes the legacy-animation tests to fail. The js/ tests can be ran in any order but all three of them together cause the state that is making the three legacy tests fail.
It looks like the legacy-animation-engine/compositing test are responding to memory pressure, but DRT is supposed to override the compositing policy option. That must be broken somehow.
The bug here is that the Internals code to reset state between tests clears the compositing policy override, allowing a test to fall into low memory mode. In WTR, we explicitly set the override to "Normal", but there is no such code in DRT.
Marking these three tests flakey in https://trac.webkit.org/changeset/234742/webkit doing this to clear noise on the tree while a solution is found.
Created attachment 368284 [details] Patch
Comment on attachment 368284 [details] Patch Clearing flags on attachment: 368284 Committed r244675: <https://trac.webkit.org/changeset/244675>
All reviewed patches have been landed. Closing bug.
*** Bug 188421 has been marked as a duplicate of this bug. ***
*** Bug 188910 has been marked as a duplicate of this bug. ***
This patch fixed two of these tests, and it also fixed other tests that I just duped here. legacy-animation-engine/compositing/backing/transform-transition-from-outside-view.html remains super flaky. Turns out that we already have a separate bug for it, bug 184611, but failures are not as before. Updated test results in http://trac.webkit.org/r245211