1329921 - Add structured metadata to bailout markers for the profiler

Status: NEW

(Core :: JavaScript Engine, defect, P3)

Description

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

Right now, we emit markers on every bailout, but they have a bunch of information encoded as a string. It would be much better if we used the same strings (or better, IDs) as the sampled stacks. Current we have embedded in the string

 - reason (bailout type, or whatever -- the TypeBarrierO in Bailout_TypeBarrierO)
 - specific thing it applied to, the jsop or whatever it is
 - line number
 - script

Comment 1

[Markus Stange [:mstange]]

Steve, have you started to look into this? It seems that passing data from js/ to the profiler is a tricky business; js/ can't include GeckoProfiler.h directly, so instead the profiler needs to register a callback function with JS for any interactions between the two. The current marker is inserted with a callback function that only accepts a simple string.