google/benchmark

[FR] Allow modification of perf attributes

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#1,897 opened on Jan 6, 2025

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enhancementgood first issuehelp wanted

Description

Is your feature request related to a problem? Please describe.

I have a multi-threaded benchmark where I'd like the performance counters to only measure the main thread.

Describe the solution you'd like

Setting the inherit attribute to false instead of true before passing the struct to perf_event_open would solve my issue. Some sort of configuration option which allows me to set this would be ideal. Maybe this can be extended to other attributes as well instead of hardcoding them.

Describe alternatives you've considered

Currently, I have to set it to false and recompile google benchmark.

Contributor guide

Tech stack
cpp
Domain
performancebackend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
C++ basicsLinux perf events
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The issue requests allowing modification of perf event attr fields, specifically the 'inherit' attribute in src/perf counters.cc at line 151. Investigate how to expose a configuration option to set these attributes, possibly via command line flags or a struct passed to the benchmark. Check existing comments for any maintainer suggestions on acceptable design.