942054 - bump up range and increase bucket count for reflow time telemetry metrics

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[John Daggett (:jtd)]

As noted in bug 942049, telemetry data shows a lot of long-running reflows.  The data for Firefox 24 shows that 29 million reflows take more than 3 secs.  Since a lot of these basically reflect chrome hangs, I propose we bump up the max value for these metrics and increase the number of buckets:

HTML_FOREGROUND_REFLOW_MS
HTML_BACKGROUND_REFLOW_MS

Might be interesting to log additional metrics *when* the reflow time is above a given threshold, but it's probably a good thing to bump these ASAP.

Comment 1

[Nathan Froyd [:froydnj]]

Don't forget to rename the histograms when you change the parameters.

Comment 2

[John Daggett (:jtd)]

Attachment: patch, bump range and bucket count for content reflows

Add more buckets and extend the range for content reflow metrics. Also add a new boolean metric, LONG_REFLOW_INTERRUPTIBLE, which tracks whether long reflows were interruptible or not.

The XUL reflow times don't have very many long running reflows so I didn't do the same for them.

Comment 3

[John Daggett (:jtd)]

Attachment: patch, bump range and bucket count for content reflows

Bump the names of the updated metrics to "xxx_2".

Comment 4

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 8337505 [details] [diff] [review]
patch, bump range and bucket count for content reflows

r=me.  Thank you!

Comment 5

[John Daggett (:jtd)]

Pushed to inbound
https://hg.mozilla.org/integration/mozilla-inbound/rev/555b1691b0a4

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/555b1691b0a4