Bug: Intermittent browser/base/content/test/performance/browser_startup_content_mainthreadio.js | no main thread IO when we expected some for process Web Content: /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi (XR
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2020-06-25 23:22:53+00:00
Resolved: 2020-07-21 17:05:55+00:00

**Filed by:** abutkovits [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer.html#?job_id=307586999&repo=autoland
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/Y0n8dBNKTfuczvEGA4cYLg/runs/0/artifacts/public/logs/live_backing.log

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[task 2020-06-25T22:15:53.444Z] 22:15:53     INFO - TEST-START | browser/base/content/test/performance/browser_startup_content_mainthreadio.js
[task 2020-06-25T22:15:53.460Z] 22:15:53     INFO - TEST-INFO | started process screentopng
[task 2020-06-25T22:15:53.862Z] 22:15:53     INFO - TEST-INFO | screentopng: exit 0
[task 2020-06-25T22:15:53.863Z] 22:15:53     INFO - Buffered messages logged at 22:15:53
[task 2020-06-25T22:15:53.864Z] 22:15:53     INFO - Entering test bound 
[task 2020-06-25T22:15:53.864Z] 22:15:53     INFO - known main thread IO paths for Web Content process:
[task 2020-06-25T22:15:53.865Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/omni.ja - stat: 1, listedPath: GreD:omni.ja
[task 2020-06-25T22:15:53.865Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/omni.ja - stat: 1, listedPath: XCurProcD:omni.ja
[task 2020-06-25T22:15:53.865Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi - stat: 1, listedPath: XREAppFeat:webcompat@mozilla.org.xpi
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/features/formautofill@mozilla.org.xpi - ignoreIfUnused: true, stat: 1, listedPath: XREAppFeat:formautofill@mozilla.org.xpi
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | Found profile for Web Content process - 
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - (NSPRIOInterposer) stat - /builds/worker/workspace/build/application/firefox/omni.ja
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - (NSPRIOInterposer) stat - /builds/worker/workspace/build/application/firefox/browser/omni.ja
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | Web Content startup profiles should have IO markers in builds that are not RELEASE_OR_BETA - 
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/omni.ja as many times as expected in Web Content process - 
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/browser/omni.ja as many times as expected in Web Content process - 
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi allowed 1 more times in Web Content process - 
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - Buffered messages finished
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | no main thread IO when we expected some for process Web Content: /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi (XREAppFeat:webcompat@mozilla.org.xpi) - 
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - Stack trace:
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - chrome://mochikit/content/browser-test.js:test_ok:1299
[task 2020-06-25T22:15:53.866Z] 22:15:53     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_content_mainthreadio.js:null:431
[task 2020-06-25T22:15:53.867Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/browser/features/formautofill@mozilla.org.xpi allowed 1 more times in Web Content process - 
[task 2020-06-25T22:15:53.867Z] 22:15:53     INFO - known main thread IO paths for Privileged Content process:
[task 2020-06-25T22:15:53.867Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/omni.ja - stat: 1, listedPath: GreD:omni.ja
[task 2020-06-25T22:15:53.867Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/omni.ja - stat: 1, listedPath: XCurProcD:omni.ja
[task 2020-06-25T22:15:53.867Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi - stat: 1, listedPath: XREAppFeat:webcompat@mozilla.org.xpi
[task 2020-06-25T22:15:53.867Z] 22:15:53     INFO - TEST-FAIL | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | profile for Privileged Content process not found - 
[task 2020-06-25T22:15:53.871Z] 22:15:53     INFO - known main thread IO paths for WebExtensions process:
[task 2020-06-25T22:15:53.871Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/omni.ja - stat: 1, listedPath: GreD:omni.ja
[task 2020-06-25T22:15:53.872Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/omni.ja - stat: 1, listedPath: XCurProcD:omni.ja
[task 2020-06-25T22:15:53.872Z] 22:15:53     INFO -   /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi - stat: 1, listedPath: XREAppFeat:webcompat@mozilla.org.xpi
[task 2020-06-25T22:15:53.873Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | Found profile for WebExtensions process - 
[task 2020-06-25T22:15:53.873Z] 22:15:53     INFO - (NSPRIOInterposer) stat - /builds/worker/workspace/build/application/firefox/omni.ja
[task 2020-06-25T22:15:53.873Z] 22:15:53     INFO - (NSPRIOInterposer) stat - /builds/worker/workspace/build/application/firefox/browser/omni.ja
[task 2020-06-25T22:15:53.873Z] 22:15:53     INFO - (NSPRIOInterposer) stat - /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi
[task 2020-06-25T22:15:53.873Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | WebExtensions startup profiles should have IO markers in builds that are not RELEASE_OR_BETA - 
[task 2020-06-25T22:15:53.874Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/omni.ja as many times as expected in WebExtensions process - 
[task 2020-06-25T22:15:53.874Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/browser/omni.ja as many times as expected in WebExtensions process - 
[task 2020-06-25T22:15:53.874Z] 22:15:53     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | stat on /builds/worker/workspace/build/application/firefox/browser/features/webcompat@mozilla.org.xpi as many times as expected in WebExtensions process - 
[task 2020-06-25T22:15:53.880Z] 22:15:53     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-06-25T22:15:53.881Z] 22:15:53     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_content_mainthreadio.js | Unexpected main thread I/O behavior during child process startup; open the profile_startup_content_mainthreadio.json artifact in the Firefox Profiler to see what happened