1323790 - Linux debug R8 reftest suite leaking objects

Status: RESOLVED INCOMPLETE

(Core :: Graphics: WebRender, defect, P3)

Description

[Kartikaya Gupta (email:[e-mail])]

After merging from m-c in https://treeherder.mozilla.org/#/jobs?repo=graphics&revision=05f6c6e2e3d45128c268b6681980a91febabfab2 the Linux-QR R8 debug reftests started showing leaks, in both non-e10s and e10s. It's probably leaking in opt too, but we don't do leakchecking in opt so it's not showing up.

I'm doing a local build to chase this down, and will probably do some try pushes to bisect the m-c merge as well.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

Attachment: Refcount stacks

So after spending half the day debugging this it looks like this isn't even a real problem. The leak only showed up in the TreeHerder snippet because of the test failure that went along with it. The leak is pre-existing - it shows up in the logs of previous green R8 runs but TreeHerder ignores the failure.

That being said I did repro this locally and looked at the stacks that added/released refptrs to the leaked WebRenderBridgeChild instance. There were two dangling pointers, from ImageClientSingle::ImageClientSingle and one from TextureClientRecycleAllocator::TextureClientRecycleAllocator. The full stacks along with the refcnt changes are attached.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

I'm going to close this for now since it doesn't seem to be an issue on TH.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

Looking at the log [1] more closely it looks like we're actually leaking thousands of WebRender*Layer instances too, so we should definitely track this down at some point.

[1] https://treeherder.mozilla.org/logviewer.html#?job_id=119871&repo=graphics#L24440

Comment 4

[Intermittent Failures Robot]

8 failures in 526 pushes (0.015 failures/push) were associated with this bug in the last 7 days.  

Repository breakdown:
* graphics: 8

Platform breakdown:
* linux64-qr: 8

For more details, see:
https://brasstacks.mozilla.com/orangefactor/?display=Bug&bugid=1323790&startday=2016-12-12&endday=2016-12-18&tree=all