Bug 514490 implements per tab network prioritization. I request a preference to be added to control this behavior. I am not sure how much useful this is to an end-user, but it is very much essential for someone like me. I am using Firefox to run automated tests of various websites and gather network performance metrics for those websites. I would be running multiple instances of the browser each with multiple tabs. In such a setup the prioritization will invariably skew the network numbers. So it is highly desirable that a preference be in place to disable this feature. On discussing about this with zpao, it appears that this whole feature can be disabled by commenting out one single line. So technically adding a preference is a fairly easy work. I strongly urge the Mozilla folks to approve this preference to be added.

(In reply to comment #0) > On discussing about this with zpao, it appears that this whole feature can be > disabled by commenting out one single line. So technically adding a preference > is a fairly easy work. It would be "fairly easy" to add a pref check there, BUT I that's not how we would want to do it. That would cause windows opened after the pref change to be affected, but windows opened before would still be prioritized (or not, depends on which way you flip the pref). What we really would need to do is set up a pref observer and set/reset priorities when the pref is changed. My early implementations (attachment 403912 [details] [diff] [review] was the last) did have that, but there was a fair amount of code to handle the pref. So it's a bit more work than "fairly easy" implies, but I already did it once.

We don't need to support instant-apply for hidden prefs.

(In reply to comment #2) > We don't need to support instant-apply for hidden prefs. Also, I don't think this would be needed as per the use case that I have stated. We do not really switch between regular FF usage and using it for automation work. And, does this need to be brought to someone's attention for getting an approval?