Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox lags after locking OS

  • 2 replies
  • 0 have this problem
  • 23 views
  • Paskiausią atsakymą parašė 1majom

more options

If I lock my machine for more than a few minutes and then log on again, it's always the same. I unlock my system and feel some kind of slowness in Firefox. When I switch from the currently open tab in Firefox, the new tab is highlighted in the tab bar, but the content part of the window is frozen. If I quickly open htop, I can see that the main Firefox process is suddenly using about 130% of my CPU. The only solution I have found is to quickly open htop after unlocking the system, send a SIGKILL to the main Firefox process and reopen it. This way the freezing, slowing problem is nowhere to be seen.

I am running Debian 12 with Firefox 115.4.0esr (64-bit). I have more than enough RAM and CPU.

If I lock my machine for more than a few minutes and then log on again, it's always the same. I unlock my system and feel some kind of slowness in Firefox. When I switch from the currently open tab in Firefox, the new tab is highlighted in the tab bar, but the content part of the window is frozen. If I quickly open htop, I can see that the main Firefox process is suddenly using about 130% of my CPU. The only solution I have found is to quickly open htop after unlocking the system, send a SIGKILL to the main Firefox process and reopen it. This way the freezing, slowing problem is nowhere to be seen. I am running Debian 12 with Firefox 115.4.0esr (64-bit). I have more than enough RAM and CPU.

All Replies (2)

more options

1majom said

the content part of the window is frozen.

If the content updates when you switch to a different window (eg Alt+Tab), you may be able to rescue it by going to about:support and clicking the button next to "Device Reset" (may appear as "gpu-device-reset").

You might be able to avoid it by disabling hardware acceleration and/or running in native Wayland by setting the environment variable MOZ_ENABLE_WAYLAND=1.

more options

zeroknight said

If the content updates when you switch to a different window (eg Alt+Tab), ...

Sadly switching to an other window never helped. But I will try disabling hardware acceleration and will reply.