[webkit-reviews] review requested: [Bug 78876] Fine-grained JSC JIT code profiling at the function level : [Attachment 127585] updated patch

[bugzilla-daemon at webkit.org]

Yuqiang Xian <yuqiang.xian at intel.com> has asked  for review:
Bug 78876: Fine-grained JSC JIT code profiling at the function level
https://bugs.webkit.org/show_bug.cgi?id=78876

Attachment 127585: updated patch
https://bugs.webkit.org/attachment.cgi?id=127585&action=review

------- Additional Comments from Yuqiang Xian <yuqiang.xian at intel.com>
Gavin, thanks for pointing out the problem.

Yes, as you mentioned, I think we should do the JIT symbol mapping stuffs after
sampling. And I think when the profiling is ended and the profile is reported
the CodeBlocks _should_ be alive. As the CodeProfiling stuff will be cleaned-up
when we get out of evaluate(), while the CodeBlocks are allocated in the heap
which are supposed to be reclaimed later. So this new patch is based on this
assumption.

Example profiling output:

<CodeProfiling /mnt/supplement/kraken/tests/kraken-1.1/ai-astar.js:1>
Total samples: 8354
    8259: [[DFGJIT]] : search (Lines: 48-118) (8259 stack top)
      82: [[EngineCode]] (0 stack top)
	  82: <unknown> (82 stack top)
      10: [[DFGJIT]] : neighbors (Lines: 125-143) (10 stack top)
       1: [[DFGJIT]] : findGraphNode (Lines: 7-12) (1 stack top)
       1: [[DFGJIT]] : init (Lines: 38-47) (1 stack top)
       1: [[BaselineOSR]] : init (Lines: 38-47) (1 stack top)
</CodeProfiling /mnt/supplement/kraken/tests/kraken-1.1/ai-astar.js:1>