Open new window will run out of memory

[OwenChia]

Every time when I try to open a new window, it will run out of memory and then get killed.
I had to disable this, how to fix this?
I'm running Firefox 46.0 on Gentoo amd64, the DE is KDE 5.

[phanimahesh]

Can not reproduce on FF 46.0.1, Ubuntu + Unity. Did you try reproducing the issue with a clean profile and just pentadactyl enabled?

[OwenChia]

@phanimahesh
Can not reproduce with clean profile.
I have 170 tabs opend, maybe there are too many tabs?

[phanimahesh]

Possible. Each loaded tab can take upto a few MB depending on the page and plugins you have. At 170 tabs, about 2G RAM is not a bad estimate. New window takes up way more memory than a new tab, since a new window is a new process.

[OwenChia]

I have 6G memory and 6G swap, and just opened only one new window, there are takes up too many memory.

[phanimahesh]

Firstly, my estimate of 2GB was infact bad. Looks like FF takes much more RAM than I expected. Still 6+6 is a very large number, and this should not happen. Since you can not repro with a clean profile, the next logical step is to enable addons/plugins one by one in a clean profile and trying to repro. You should be able to arrive at a minimal configuration with which this can be reproduced.

As a quick check, is this issue reproducible with all addons except pentadactyl enabled? With all addons enabled but just a few tabs open?