- Cartlannaithe
How to debug memory problems with extensions?
I'm having huge memory problems with Firefox. In about:performance I can see that the extensions process takes up way too much memory. When I start Firefox it usually sho… (tuilleadh eolais)
I'm having huge memory problems with Firefox. In about:performance I can see that the extensions process takes up way too much memory. When I start Firefox it usually shows a memory usage of around 180MB. However, at some point the memory usage of the extensions process starts to increase and it doesn't stop increasing until my RAM is full and then it increases even further. It increases until I restart Firefox or until it uses so much RAM that my computer runs incredibly slow.
Below you can see a screenshot of the Task Manager showing how much RAM is available on my computer and a screenshot of the about:performance page showing the memory usage of the Extensions process. The RAM available on my laptop is 10GB (the default configuration was 4GB of soldered RAM plus 4GB of exchangeable RAM. I have upgraded from 4+4GB to 4+8GB but 2GB of the soldered RAM on this laptop are used as GPU memory so the remaining RAM is 10GB). The about:performance screenshot shows a memory usage of 13GB for the extensions process which is possible because Windows automatically pages RAM on the SSD when I'm running low on available physical memory. This enables programs to actually use more memory than the available physical RAM but of course programs become incredibly slow when the RAM is full and huge parts of memory have to be paged on the SSD.
My actual question: How can I find the cause of these memory problems?
What I've tried so far
- I have created a memory report on about:memory. The result is at the bottom of this post. - I have watched the about:performance page and tried to find out what action triggers the memory usage of the extensions process to increase. At the start of the browsing session the memory usage is only at around 180MB. It stays like that for a while. At some point it starts to steadily increase by many GBs. But I couldn't find the cause. I don't know what triggers the extensions process to increase memory usage. - I could simply disable extensions and see if the problem gets solved. But I want to know which exact extension causes this problem. It is very difficult to find out which one it is because I have many extensions and I don't know what causes the memory usage to increase. So I would have to disable extensions one by one and wait for an indefinite amount of time and check whether memory usage stays low. But I don't know how long I have to wait until the memory usage would increase because I couldn't identify what triggers it to increase.
Rather than just using trial and error I would like to find a way to use debugging tools to exactly determine what causes the problem.
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This (https://pastebin.com/U3QXTAt9) is the memory report from about:memory. This contains the whole extension (pid 18332) section (copy & pasted by selecting the text on the about:memory page). I have left out the rest because I don't know if it contains private data. Please note: this is not taken from the same browsing session as the screenshot that shows a memory usage of 13GB. Why? Because programs run very slow when memory is low and large parts of memory are being paged. The debug tools usually require a lot of RAM and CPU performance so it's very difficult to use the debug tools when the memory is already full and programs are already running slow. This memory report shows a very high memory usage of the extensions process. In this case it's "only" 3.5GB but it was taken in an early stage of the increasing memory usage. As shown in the screenshot below, memory usage can go even higher than the available physical RAM on my computer. The memory report doesn't clearly show which extension is responsible for the high memory usage. In the memory report, I can only see a high memory usage for the items gc-buffers and gc-heap which leads me to think that the memory problem has something to do with the garbage collector. However, I cannot see which extension is responsible for this. No item in this list with a description that identifies a specific extension has a high memory usage. This is only an excerpt from the memory report (only the extension section). I went through the whole memory report with Ctrl + F "moz-extension" and looked for items with a high memory usage but I didn't find a single item with high memory usage that belongs to a specific extension.