Cumulative CPU means the total amount of CPU used by the addon or tab, since measuring began.
This might be useful to measure the long-term impact of addons or tabs which aren't always busy, and so might not be caught easily by watching the about:performance tab.
Actually, the reason I want this is that I suspect one of my addons causes Firefox to slow down during startup, but then goes quiet after startup. I would like to find out which one it is!
Therefore, whilst a checkbox on the about:performance page to toggle cumulative recording would be good, I would also like:
- Recording of the data even when about:performance is not open, and
- a setting (e.g. in about:config) which would last between restarts, or
- a flag on the command-line which would turn the option on.
(If people want a similar feature for memory, I suppose it might be useful to display the peak memory usage for each addon/tab, rather than the current memory usage.)
Thanks for submitting an idea to the Mozilla Connect community! Your idea is now open to votes (aka kudos) and comments.
Thanks for the great suggestion, @joeytwiddle. We have captured this in bugzilla so that it appears in our teams' backlogs.