User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:51.0) Gecko/20100101 Firefox/51.0 Build ID: 20170103031119 Steps to reproduce: Refreshing the page with developer console open results in high memory consumption over time. Attached are the memory reports before and after 20 consequtive reloads (ctrl+shift+r) of the same page with the developer console open. Actual results: Running out of memory over time results in system becoming unresponsive under huge system load. Expected results: Memory consumption should not increase that much on each reload.

Forgot to add that, closing the developer console and running "minimize memory usage" on about:memory page before the system gets unresponsive gets everything back to normal.

Apparently the huge system load was caused by kswapd. Even though the same working routine continues and nothing changed other than updating to 52.0b5, i don't see kswapd taking over the system anymore. It was happening in the previous versions up until 52.0b5. But developer console still eats up lots of memory. I am running on zram with with vm.swappiness = 10. I've been seeing these topics on forums about kswapd going crazy on such systems and it being a nasty bug with no solution yet. But apparently 52.0b5 made it occur less then before, if not prevented/stopped causing it totally.

Same issue here, just testing websites html/css/javascript after a couple of hours the system gets unresponsive. Using version 53.0a2 (2017-02-21) (32-bits)

Using Firefox 54.0.1 (32-bit), I'm having the same issue. With developer tools on, if I do a lot of browsing or if the site I'm on refreshes periodically, browsing gradually slows down. If I leave developer tools active overnight on a periodically-refreshing site, browsing is v-e-r-y s-l-o-w when I come back to it in the morning. I need only close the developer tools, and browsing speed becomes normal almost immediately. I will try to provide hard data soon. Thanks.

Refreshing `data:text/html,<meta charset=utf8><script>console.log("hello", document)</script>` a lot seems to increase memory consumption.