Conversation
Measure CPU time via pthread_getcpuclockid on Linux and Mach thread_info
on macOS, and surface it two ways:
1. Attached to every "Thread Running" marker interval as `cpu_time`.
Hovering over the marker in the Firefox profiler shows how much
CPU the thread actually consumed during that run, making preemption
visible.
2. Emitted as per-sample threadCPUDelta on the samples table when the
new `cpu_time:` option is set. The Firefox profiler renders this as
a per-thread CPU utilization track. Opt-in because the profiler
swaps the timeline's activity graph from category-coloured sample
density to CPU utilization when the field is present.
Fixes #29.
Owner
|
Thanks for looking into this ❤️ Have you gotten any sense of the overhead? In my experience, reading from the CPU time clocks on linux is very expensive. |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #29.
Surfaces CPU time in wall-mode profiles two ways.
cpu_time. Hovering over the marker in the Firefox profiler shows how much CPU the thread actually consumed during that run, making preemption visible.threadCPUDeltawhenVernier.profile(cpu_time: true)is set. The Firefox profiler renders this as a per-thread CPU utilization track.Opt-in on the sample side because Firefox swaps the timeline's activity graph from category-coloured sample density to CPU utilization when the field is present, which reads as gaps for I/O-heavy workloads.