1152578 - Tweaks and improvements for Jit Coach UI

Status: RESOLVED INVALID

(DevTools :: Performance Tools (Profiler/Timeline), defect)

Description

[Kannan Vijayan [:djvj]]

This is a general bug I'm making to document analysis towards improvements to the devtools jit coach UI.

Comment 1

[Kannan Vijayan [:djvj]]

These are the notes I took yesterday trying to profile the PlayCanvas game 'tanx':

1. Pause times when streaming long-running profiles are VERY LONG.  We need to find a way to shorten this, most likely by de-duping things more aggressively in streaming.

2. A lot of optimization-info failures are inlining failures in callers where the inlining failure is not that big of a deal.  We should skip considering OptInfo indicating inlining failures on return-addresses, and keep OptInfo indicating inlining failures on leaf-addresses.  The reasoning for this is as such:  As it's very unlikely that a leaf sample will fall within the native code emitted for a "JSOP_CALL" bytecode, if we get a sample in that region it implies that it's very likely that the call site is heavily utilized and should have been inlined.  In other cases, we can't be sure that the inlining would have been significant, and thus omit the info.

3. GetProp, SetProp, GetElem, and SetElem should document their last successful strategy.  Currently, the instrumentation for these optimizations leaves the last successful strategy implicit, and simply documents the failure of the last failed strategy.

4. The inverted call-tree view in the profiler doesn't order by self cost of the function.  This should be fixed (see bug 1151973).

5. The call-tree view should add an emblem to frames which have optimization information associated with them.  It's very time consuming and opaque to figure out which frames have optimization info when trying blindly to click across them hoping that the right-hand-side pane fills up with info.

6. The right-hand optinfo pane should be hide-able, and start out hidden by default.  When an optinfo emblem is clicked, it should become unhidden and display the info.

Comment 2

[Jordan Santell [:jsantell] [@jsantell]]

1. We have several bugs open for this to make this more pleasant on the front end, but any backend improvements here would be awesome -- related to bug 1150291? or is that just for jit data?

5. bug 1150295 
6. I think a few of these visual changes will be solved by making a new view for this within the performance tools

Comment 3

[Jordan Santell [:jsantell] [@jsantell]]

Most of these are address, I believe. 6 will no longer be an issue as it'll be its own panel. The remaining issues are 2 and 3, and I'm not sure if those are still an issue as I don't quite understand

Comment 4

[Kannan Vijayan [:djvj]]

I think (3) is not really an issue, and was based on a misunderstanding on my part, and (2) has been addressed by the "only show optimization info related to leaf frames" work.

Comment 5

[Jordan Santell [:jsantell] [@jsantell]]

Ok sounds good, closing this bug then