1242018 - Memory is retained when loading snapshots for too long

Status: RESOLVED WORKSFORME

(DevTools :: Memory, defect, P3)

Description

[Jordan Santell [:jsantell] [@jsantell]]

STR:


* Start a fresh firefox
* Open memory tools and import attachment from bug 1226319, 
* Let it finish loading and close devtools

ER: Firefox that only has a default tab open, and nothing else, is taking up a reasonable amount of ram.

AR: For a few minutes, the instance of Firefox with just a default tab open, and devtools closed, can take several GBs of memory. Eventually it gets cleared, but it's a bit too long, like atleast a few minutes. Maybe we can force a GC when closing the toolbox, or clearing out snapshots?

Comment 1

[Jordan Santell [:jsantell] [@jsantell]]

Snapshot; http://media.fitzgeraldnick.com/dumping-grounds/76479223.fxsnapshot

Comment 2

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

If you go to about:memory and do a "minimize memory usage" does it go away immediately?

Comment 3

[Jordan Santell [:jsantell] [@jsantell]]

Seeing the STR go from ~450MB to ~1.3GB when loading that snapshot, but as soon as I close my tab or toolbox, it goes down pretty rapidly, even after trying a few times. I know it's unpredictable, but if the scenario can occur where it takes a few minutes, then maybe we should consider a flush when closing the toolbox. If you don't think that necessary, or a very edge case, then let's close this.

Comment 4

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

Since it appears to be going away on the next GC/CC cycle, I think we have nothing to worry about. If Firefox is memory constrained, it will trigger a cycle sooner. If it is not memory constrained, then having some unused memory floating for a little bit is no biggie.