janestreet / janestreet/magic-trace

Bug when decoding: "duration_complete event must have start tick (166428285) greater than end tick (166428276)"

Open
#319 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

bug
Dominant language
OCaml
Stars
6.3k
Forks
209
PR merge metrics
No merged PRs in 30d

Description

When running `./magic-trace run -working-directory workdir -full-execution -multi-thread ./dotnet/dotnet -- benchmark/Abc.TradingPerfTests.dll`

magic-trace end up throwing when writing the trace with the error:
`"duration_complete event must have start tick (166428285) greater than end tick (166428276)"`

Thanks for helping us make magic-trace better!

Please consider answering any subset of the following questions, based on what you think
is most relevant to your report:

> - How can we, magic-trace developers, reproduce the issue you're seeing?

If needed I can provide a zip that contains everything to reproduce the issue.

> - What version of perf userspace tools are you running? `perf --version`

`perf version 6.8.12`

- What CPU do you have? `cat /proc/cpuinfo`

`Intel(R) Xeon(R) Gold 6146 CPU`

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the failure with the provided magic-trace command, perf 6.8.12, and the reported Intel Xeon CPU. Trace the decoding and trace-writing path that reports the inverted duration_complete ticks, then verify that the same workload produces a valid trace without throwing.

Written by the indexing model from the issue text.

Assessment

Tech stack
linux, ocaml
Domain
observability, performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.