1548419 - 128.15 - 12930.27% tp5n main_startup_fileio / tp5n nonmain_startup_fileio (windows7-32-shippable) regression on push 9a0ce3016f03a914367e86c8339a8b885e309c83 (Wed May 1 2019)

Status: RESOLVED WONTFIX

(Firefox :: General, defect)

Description

[Arthur Iakab [arthur_iakab]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/rev/cbdf3fdfcbac59d4ccac118d2e6a96ac360a94a5

As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

12930% tp5n main_startup_fileio windows7-32-shippable opt e10s stylo 767,075.17 -> 99,951,973.67
128% tp5n nonmain_startup_fileio windows7-32-shippable opt e10s stylo 1,182,289.00 -> 2,697,402.42

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=20745

On the page above you can see an alert for each affected platform as well as a link to a graph showing the history of scores for this test. There is also a link to a treeherder page showing the Talos jobs in a pushlog format.

To learn more about the regressing test(s), please see: https://wiki.mozilla.org/Performance_sheriffing/Talos/Tests

For information on reproducing and debugging the regression, either on try or locally, see: https://wiki.mozilla.org/Performance_sheriffing/Talos/Running

*** Please let us know your plans within 3 business days, or the offending patch(es) will be backed out! ***

Our wiki page outlines the common responses and expectations: https://wiki.mozilla.org/Performance_sheriffing/Talos/RegressionBugsHandling

Comment 1

[Alex Thayer [:alexical] (she/her)]

Ah - I should have called this out. This is expected and innocuous. The difference is just due to the fact that the previous mechanism (mapping the file and reading from that memory to fetch the pages off of the disk) doesn't show up as file IO for the purposes of the test, when in fact it still is. I.e., there should be no change in performance for Windows 7, just a change in reporting. I believe WONTFIX is right for this case?