736383 - Add memory reporter for TableUpdates

Status: RESOLVED WONTFIX

(Toolkit :: Safe Browsing, defect)

Description

[Nicholas Nethercote [inactive]]

Attachment: DMD output

With the new version of DMD (bug 717853) I found that TableUpdates in the url-classifier are taking up a decent chunk of memory.  In one run where I had 5 gmail tabs open, TableUpdates accounted for over 3.8MB of memory, in mAddPrefixes, mSubPrefixes, mAddCompletes, mSubCompletes.  I've attached the relevant part of DMD's output, which shows a tree of stack traces from allocation points.

I'm not certain, but I think we can report those by traversing over nsUrlClassifierDBService::mWorker->mTableUpdates.

Comment 1

[Gian-Carlo Pascutto [:gcp]]

Do we want to add memory reporting for transient datastructures? Or are you saying here there's a potential memory leak?

TableUpdates are supposed to exist for +-15s every half hour.

Comment 2

[Nicholas Nethercote [inactive]]

(In reply to Gian-Carlo Pascutto (:gcp) from comment #1)
> Do we want to add memory reporting for transient datastructures? Or are you
> saying here there's a potential memory leak?
> 
> TableUpdates are supposed to exist for +-15s every half hour.

I don't know if it's a leak.  It just showed up in the DMD snapshot.  I guess I may have got lucky and hit that 15s, but maybe they actually hang around longer than that.

Comment 3

[Nicholas Nethercote [inactive]]

I don't recall seeing these again.  Probably not worth doing.