Except that closing Firefox did not work: UI was gone, but firefox process kept running in background. Killing by signal 1 closed firefox finally. After restart (with same tabs) CPU usage is much lower, at about 10%.
Except that closing Firefox did not work: UI was gone, but firefox process kept running in background. Killing by signal 1 closed firefox finally. After restart (with same tabs) CPU usage is much lower, at about 10%.