474829 - Add internal profiling support to TraceMonkey

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, enhancement)

Description

[David Mandelin [:dmandelin]]

For understanding perf and perf problems, I've found it incredibly useful to be able to know things like how much time is spent on trace, how many ops are executed on trace, etc. I have some personal patches for this. They aren't clean enough to be landed but I can put them here now and work on that after the 3.1 bug fix push is done. 

By the way, this kind of instrumentation should be available in opt builds and not just debug builds. 

There are some other useful things we could do using the same basic infrastructure like record the stream of JSOP codes that are executed, which would help delta debug semantic bugs.

Comment 1

[David Mandelin [:dmandelin]]

Attachment: Internal timing instrumentation

Comment 2

[David Mandelin [:dmandelin]]

Attachment: Tracing-related event count instrumentation

Comment 3

[David Mandelin [:dmandelin]]

Attachment: JSOP execution mode counter instrumentation

Comment 4

[Ryan VanderMeulen [:RyanVM]]

Obsolete with the removal of tracejit.