Bug 225666 – [ BigSur wk2 arm64 ] http/tests/cache/disk-cache/redirect-chain-limits.html (layout-test) is a flaky timeout

• Component: Page Loading
• Status: NEW

[Robert Jenner]

http/tests/cache/disk-cache/redirect-chain-limits.html

is a flaky timeout on macOS BigSur wk2 Release on Apple Silicon Macs only. 

HISTORY:
https://results.webkit.org/?suite=layout-tests&test=http%2Ftests%2Fcache%2Fdisk-cache%2Fredirect-chain-limits.html 


TIMEOUT TEXT:
-Test the limits of redirect chain length.
+#PID UNRESPONSIVE - WebKitTestRunner (pid 22545)
+FAIL: Timed out waiting for notifyDone to be called
 
-On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
-
-
-Redirect chain length: 1
-Response status code: 200
-Response source: Disk cache
-
-Redirect chain length: 5
-Response status code: 200
-Response source: Disk cache
-
-Redirect chain length: 6
-Response status code: 200
-Response source: Network
-
-Redirect chain length: 20
-Response status code: 200
-Response source: Network
-
-Redirect chain length: 40
-Response status code: 0
-Response source: Null response
-
-PASS successfullyParsed is true
-
-TEST COMPLETE
-
+#EOF
+#EOF

[Robert Jenner]

Upon further inspection it looks like this test also has a history of flaky timeouts on Debug as well. The first recorded timeout occurred at r276217 and has been inconsistent since.

Since this only occurs on Apple Silicon Macs, I can't reproduce the timeouts as I do not have access to said system type. 

I have updated the expectations to Pass Timeout here:
https://trac.webkit.org/changeset/277337/webkit

[Radar WebKit Bug Importer]

<rdar://problem/77857419>

[Alexey Proskuryakov]

This test is fairly slow on Intel too, taking ~11 seconds in WK2 Release. It is roughly 3x slower on Apple Silicon, which is surprising, but I'm not seeing the same on an internal bot. So this could be a configuration issue of some kind.

[Robert Jenner]

As per @Alexey's recommendation, I have updated the test expectations to [ Slow ] instead of [ Pass Timeout ] here:
https://trac.webkit.org/changeset/277398/webkit

[Robert Jenner]

There was an issue where the Mac mini this test was running on was using 10gb of its ram. This may have been the reason this test was timing out/running slow. I believe the ram usage issue has been resolved. I also marked the test as slow, and the test is now taking between 5-8 seconds to run and pass. Before, it was taking about 30 seconds to run.