Bugzilla

(In reply to joshuasend1 from comment #5)
> I did have to scroll down to the bottom of the page, and then scroll back up to the top - which causes the rendering to freeze for about 80 seconds (screenshots attached). After that it is still a bit laggy but more acceptable.

Thanks! Yikes, 86 seconds of jank is terrible (but unfortunately, totally possible if a page does enough work without yielding; that's why we offer the "stop this page" button, as a way to halt whatever the page is doing).

During the shorter-hang that I see locally (possibly due to different hardware), I can confirm that our rendering is not-entirely-responsive -- sometimes there are blank patches if I drag my scrollbar up and down.

> I switched to Chrome and tried and in fact do find it hangs with the extra two steps above. This indicates Github changed something recently that causes this -- I'll probably file an issue with them too.

Question for you, just to clarify: does Chrome hang for roughly the same duration as Firefox? (You can capture a profile of the behavior at Chrome by following instructions at https://developer.chrome.com/docs/devtools/evaluate-performance/reference/ , to get a timeline etc.)

> I think I probably didn't spot it in chrome in my initial test because the page was still rendered (though "not responsive"). In firefox the page rendering freezes and is unresponsive. Hopefully it is useful in some way to the firefox team!

(For what it's worth: I just reproduced an unrendered blank area in Chrome (when scrolling up and down, during the hang); though I agree, it does seem a little easier to trigger that behavior in Firefox.)

(In reply to joshuasend1 from comment #5)
> I did have to scroll down to the bottom of the page, and then scroll back up to the top - which causes the rendering to freeze for about 80 seconds (screenshots attached). After that it is still a bit laggy but more acceptable.

Thanks! Yikes, 86 seconds of jank is terrible (but unfortunately, totally possible if a page does enough work without yielding; that's why we offer the "stop this page" button, as a way to halt whatever the page is doing).

During the shorter-hang that I see locally (possibly due to different hardware), I can confirm that our rendering is not-entirely-responsive -- sometimes there are blank patches if I drag my scrollbar up and down.

> I switched to Chrome and tried and in fact do find it hangs with the extra two steps above. This indicates Github changed something recently that causes this -- I'll probably file an issue with them too.

Question for you, just to clarify: does Chrome hang for roughly the same duration as Firefox? (You can capture a profile of the behavior at Chrome by following instructions at https://developer.chrome.com/docs/devtools/evaluate-performance/reference/ , to get a timeline etc., so you can make sure you're looking objectively.  Also If you'd like to share a Chrome profile, you can use their download button (the downarrow icon a few buttons over from their "record" button) to export the profile as a JSON file, and then you can upload that file at https://profiler.firefox.com/ to get a shareable link.)

> I think I probably didn't spot it in chrome in my initial test because the page was still rendered (though "not responsive"). In firefox the page rendering freezes and is unresponsive. Hopefully it is useful in some way to the firefox team!

(For what it's worth: I just reproduced an unrendered blank area in Chrome (when scrolling up and down, during the hang); though I agree, it does seem a little easier to trigger that behavior in Firefox.)