599499 - Implement opagent (oprofile JIT agent) support for JM

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, enhancement)

Description

[Steve Fink [:sfink] [:s:]]

See <http://oprofile.sourceforge.net/doc/devel/index.html> for the API. This would allow getting Javascript source:lineno information into oprofile dumps for JITted code (opreport and opannotate).

WebKit is working on this support: https://bugs.webkit.org/show_bug.cgi?id=32561

oprofile usage instructions (for once this is implemented) are at http://oprofile.sourceforge.net/doc/setup-jit.html

Comment 1

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: adds oprofile support to JM

Thanks for filing this, Steve! I made a small patch to add oprofile support to the method JIT a while ago, which is attached. The hard part is getting the shell and the browser to link with libopagent, which is part of oprofile. I have no idea how to do this properly.

Comment 2

[Andrew Sutherland [:asuth] (he/him)]

Bug 463730 covers adding oprofile support to TraceMonkey (no activity yet, but more cc's), not sure if the bugs should be linked somehow...

Comment 3

[Steve Fink [:sfink] [:s:]]

Attachment: add oprofile support to JM, unknown quality patch

This came up again. Some time ago, I did some of the configure stuff for integrating this. I can't actually remember how far I made it, so I'm not sure what the state of this patch is, but it probably isn't usable right now. Attaching more as a better starting point.

Comment 4

[Steve Fink [:sfink] [:s:]]

Attachment: add oprofile support to JM

I've been playing with this today. I'm attaching the patch that I've been using, even though it's slow and done the wrong way.

It sorta seems to work, though I'm not very familiar with oprofile so it's hard to tell. I did get it to spit out annotated versions of jquery.js and jquery-ui.js with call counts and times on some of the lines.

My current usage instructions, from memory:

* install oprofile
* install opagent-devel (or the equivalent)
* apply patch
* in mozconfig: ac_add_options --with-opagent
* sudo opcontrol --start-daemon --no-vmlinux
* sudo opcontrol --start
* run the browser on your test scenario
* sudo opcontrol --stop; sudo opcontrol --dump

Now you have data. opreport and opannotate will take that data and produce gibberish.

To get something vaguely interesting, run

opannotate --source --include-file='*.js' -o stuff

it'll think for a long time and spew out stuff. At the end it'll complain about not being able to find files like 'http://googleapis.com/blah/jquery.js'. wget those into a dummy directory structure (starting with 'http:'). Run again.

Now you should have annotated .js files buried in there.

Lots of work to go.

Comment 5

[Steve Fink [:sfink] [:s:]]

Attachment: opagent build

Temporary split-out patch to add some config options for opagent and other JIT code observers.

Comment 6

[Steve Fink [:sfink] [:s:]]

Attachment: opagent support for JM-generated code

Mostly attaching here as a base for bug 642320

Comment 7

[Steve Fink [:sfink] [:s:]]

Attachment: opagent build

This patch now depends on bug 642320 (instead of the other way around), which itself depends on the patches in bug 645887.

Comment 8

[Steve Fink [:sfink] [:s:]]

Attachment: opagent support for JM-generated code

This patch now depends on bug 642320 (instead of the other way around), which itself depends on the patches in bug 645887.

Comment 9

[Steve Fink [:sfink] [:s:]]

Attachment: opagent build

my clumsy attempt at configure-fu for dealing with where opagent gets installed

Comment 10

[Steve Fink [:sfink] [:s:]]

Attachment: opagent support for JM-generated code

Rewritten for new JIT registration API

Comment 11

[Steve Fink [:sfink] [:s:]]

Attachment: opagent support for JM-generated code

Rebased to be tied to the process, not the runtime, since that's how opagent works.

Comment 12

[Luke Wagner [:luke]]

JM was removed.