As of late web twitter is performing very badly in Firefox. It hitches up for hundreds to thousands of milliseconds and it's using a lot of memory. Performance profiles show the hitches are GCs/CCs (some of the collections block for over a second). According to about:memory it looks like my twitter tab has hundreds of megabytes worth of orphaned nodes even though I've reloaded the tab recently.

Attaching a performance profile as well.

Shift-reloading the tab actually makes it worse, leaking additional memory. Mashing GC/CC/Minimize on the about:memory page does not free any of the leaked memory, but does make the browser considerably slower.

(In reply to K. Gadd (:kael) from comment #2) The profile shows 9% of time in CC and 5% in GC (CC_WAITING). > Mashing GC/CC/Minimize on the about:memory page does not free any of the > leaked memory This implies that it might be a leak in the page, and not a GC/CC issue. CC Andrew for cycle collector relevance.

This is marked as a P1, so I went ahead and took it as tracking61+ as well, but it doesn't seem very clear who owns the next step here either.

(In reply to K. Gadd (:kael) from comment #0) > Created attachment 8961688 [details] > memory-report.json.gz > > As of late web twitter is performing very badly in Firefox. It hitches up > for hundreds to thousands of milliseconds and it's using a lot of memory. > Performance profiles show the hitches are GCs/CCs (some of the collections > block for over a second). According to about:memory it looks like my twitter > tab has hundreds of megabytes worth of orphaned nodes even though I've > reloaded the tab recently. Are you still seeing this? 60 and 61 were affected by bug 1447871, which causes ghost windows, and I see a few ghost windows in your about:memory report. Ghost windows are the most common cause of long CCs. RyanVM told me that they should both have a fix now.

My dev edition channel is still on 60.0b9, so would I need 62?

DevEdition tracks Beta these days. 60.0b9 has the fix in question.

Seems fixed now.

Thanks for double-checking!