1126986 - TelemetryFile.jsm compartment uses megabytes of memory!

Status: RESOLVED DUPLICATE of bug 1041616

(Toolkit :: Telemetry, defect)

Description

[Vladan Djeric (:vladan)]

Attachment: TelemetryFile.jsm memory use.txt

I was looking through my about:memory and I noticed TelemetryFile.jsm using anywhere from 1MB to 3.5 MB of memory.

The memory is mostly tied up in JS arrays.. objects --> malloc-heap --> elements/non-asm.js

I did a quick experiment and found the memory use is normal when there are no files in saved-telemetry-pings directory and memory is use is higher when there are more pings in that directory. The saved ping files themselves are about 100KB each.

I suspect we're reading in the saved ping files and somehow inflating their size by a factor of 10.

Comment 1

[Richard Newman [:rnewman]]

See also Bug 1041616. Might be a dupe.

Comment 2

[Vladan Djeric (:vladan)]

(In reply to Richard Newman [:rnewman] from comment #1)
> See also Bug 1041616. Might be a dupe.

Yup I know about that one, I marked it a blocker of this bug when I filed it.

Comment 3

[Vladan Djeric (:vladan)]

I investigated and found there is no memory "leak". On startup, Telemetry parses the saved ping files into objects, and they use 4x as much memory as JS objects than in their serialized string from.
I'll post a patch soon to only parse the ping files when needed (right before they're sent).

Comment 4

[Richard Newman [:rnewman]]

Sounds like a 100% dupe to me.