Open Bug 1421074 Opened 2 years ago Updated 1 year ago

Loading DevTools on a disk-bound machine is slow with MOZ_Z_inflate_fast


(DevTools :: Framework, defect, P3)



(Not tracked)


(Reporter: gregtatum, Unassigned)


(Blocks 1 open bug)


Loading DevTools on a disk-bound machine is slow, most of the time is spent in "MOZ_Z_inflate_fast". I tested this on my older Windows 7 machine.

This is a recording of DevTools startup, an filters on "MOZ_Z_inflate_fast":
Hum. Hard to say if it is really slow or if that's just because we are loading way too many JS files/bytes?

All this comes from module loading. Either JSM or our custom loader.
Both codepaths ends up loading JS files in/from the startup cache.
This is also used by Firefox UI. I would expect that to be decently fast.

It may be interesting to see how different is the profile if you pass "-purgecaches" to firefox
It should disable this cache and reload files from omni.jar. It should be significantly slower as I believe we store a bytecode or at least some already parsed data into the startup cache.
I will try and do another run next time I'm sitting at that computer.
Priority: -- → P3
Product: Firefox → DevTools
You need to log in before you can comment on or make changes to this bug.