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Firefox logs for troubleshooting odd behaviour

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  • Last reply by tommiy

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Hi, I'm hoping some one one can assist in directing me how to determine what exactly firefox is doing at a point in time either by logs or anything else. I have noticed that on my PC that firefox randomly at times bursts into high energy usage and consumes 10% of my CPU while doing nothing but browsing a single web page. This repeatedly occurs about once a day and I am not sure why. I have tried recreating a new profile, refreshing firefox, closing all tabs, disabling all extension when it occurs but none of this impacts the issue. Firefox still keeps working but drives the fans on my PC to start up and keep going. After about 10 minutes the CPU usage declines to normal. During the high CPU usage times if i close firefox and restart it, it restarts without consuming the CPU. I have it to restore the previous pages so that it starts back with exactly the same tabs that I had previously. Also, when it is consuming CPU if I open about:memory and click measure it never responds. After a restart about:memory responds normally. There appears to be some thing with firefox itself that is causing the issue but I can not find an obvious next step to troubleshoot where the problem may be if its not my profile, extensions or tabs i have open. Can some one point me to a more detailed logging for firefox? Thanks

Hi, I'm hoping some one one can assist in directing me how to determine what exactly firefox is doing at a point in time either by logs or anything else. I have noticed that on my PC that firefox randomly at times bursts into high energy usage and consumes 10% of my CPU while doing nothing but browsing a single web page. This repeatedly occurs about once a day and I am not sure why. I have tried recreating a new profile, refreshing firefox, closing all tabs, disabling all extension when it occurs but none of this impacts the issue. Firefox still keeps working but drives the fans on my PC to start up and keep going. After about 10 minutes the CPU usage declines to normal. During the high CPU usage times if i close firefox and restart it, it restarts without consuming the CPU. I have it to restore the previous pages so that it starts back with exactly the same tabs that I had previously. Also, when it is consuming CPU if I open about:memory and click measure it never responds. After a restart about:memory responds normally. There appears to be some thing with firefox itself that is causing the issue but I can not find an obvious next step to troubleshoot where the problem may be if its not my profile, extensions or tabs i have open. Can some one point me to a more detailed logging for firefox? Thanks

All Replies (6)

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Try about:performance to see what the tab is doing. I also use Process Explorer v16.32 from Microsoft to get more detailed info on processes.

https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer

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It could be Firefox, or something else on your system.


https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster

https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix

https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram

https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding

https://support.mozilla.org/en-US/kb/firefox-takes-long-time-start-up

https://support.mozilla.org/en-US/kb/quick-fixes-if-your-firefox-slows-down


MemTest LAST UPDATED : 12/04/2020 Could you please run a tool from http://memtest.org/ in order to check the integrity of your RAM?

You will need a thumb or disk drive to install it on.


Do you let Windows handle the page file or did you set a fixed size ? If you use a fixed size for the page file then try the former and let Windows handle the page file. How to determine the appropriate page file size for 64-bit versions of Windows {web link}

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about:performance only shows 2 items that are using little CPU. I've tried most f the other links thats are here. Its not using excessive memory (although is using 1G) and as stated i've run into the problem with a single tab and no extensions running. Firefox is the only application that appears to have an issue and it comes and goes when the application is shut down and restarted.

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Sorry should have also said windows handles my page file size.

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You could use the firefox profiler.

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Thanks I'll have a look at profiler. It happened again this morning just as i started looking at profiler. Shutdown ff and it starts back one perfectly....really odd behaviour.