Details
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Type:
Bug
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Status: Closed
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Priority:
P2: Important
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Resolution: Done
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Affects Version/s: 5.11.0 Alpha
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Fix Version/s: 5.11.0 Beta 3
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Component/s: QML: Declarative and Javascript Engine, QML: Tooling
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Labels:
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Commits:d5c7229339a916b2f1f004ec4ea9de89995c003d
Description
The QML/JS engine had the feature to write a perf map file for all its JIT-compiled JS functions. This could be turned on with QV4_PROFILE_WRITE_PERF_MAP=1.
This feature seems to no longer exist.
A workaround to still record usable perf traces is to disable the JIT compiler with QV4_FORCE_INTERPRETER=1. However that changes the result as it slows down code execution - and for profiling, one should always measure as close to a normal execution as possible.
Note that this is documented to work on https://doc.qt.io/qtcreator/creator-cpu-usage-analyzer.html.