Productize VMStructs-based stack walker #1073
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# Conflicts: # docs/ProfilerOptions.md # test/test/jfr/JfrTests.java
vans239
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Dec 6, 2024
| | `--begin function` | `begin=FUNCTION` | Automatically start profiling when the specified native function is executed. | | ||
| | `--end function` | `end=FUNCTION` | Automatically stop profiling when the specified native function is executed. | | ||
| | `--ttsp` | `ttsp` | time-to-safepoint profiling. An alias for `--begin SafepointSynchronize::begin --end RuntimeService::record_safepoint_synchronized`.</br>It is not a separate event type, but rather a constraint. Whatever event type you choose (e.g. `cpu` or `wall`), the profiler will work as usual, except that only events between the safepoint request and the start of the VM operation will be recorded. | | ||
| | `--ttsp` | `ttsp` | time-to-safepoint profiling. An alias for `--begin SafepointSynchronize::begin --end RuntimeService::record_safepoint_synchronized`.</br>It is not a separate event type, but rather a constraint. Whatever event type you choose (e.g. `cpu` or `wall`), the profiler will work as usual, except that only events between the safepoint request and the start of the VM operation will be recorded. | |
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It was apparently a result of a merge conflict. Thanks for noticing - I'll fix that.
jbachorik
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Description
Add two stack walking modes based on VMStructs:
cstack=vmfor regular use andcstack=vmxfor expert use. The former is more like a drop-in replacement for AsyncGetCallTrace, while the latter displays additional internal frames.This PR also adds
-F statsoption to measure and log duration of stack walking. It turns out thatcstack=vmperforms not worse than AsyncGetCallTrace unwinding.Related issues
#795
#995
#694
Motivation and context
This is the next step on our path to abandon use of AsyncGetCallTrace completely and make VMStructs-based unwinding the default mode in async-profiler. See #795 for more context.
How has this been tested?
Manual testing with various apps (renaissance suite, spring petclinic) + new cstack unit tests.
vm/vmx stack walking is not currently supported on macOS.UPD: macOS support has been added in f334c51
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.