Bug 511792 - Need a CPU power-related traceevent (frequency, C-state) from upstream kernel to be displayed along with CPU
Summary: Need a CPU power-related traceevent (frequency, C-state) from upstream kernel...
Status: NEW
Alias: None
Product: Tracecompass
Classification: Tools
Component: TMF (show other bugs)
Version: unspecified   Edit
Hardware: PC Linux
: P3 normal
Target Milestone: ---   Edit
Assignee: Project Inbox CLA
QA Contact: Project Inbox CLA
URL:
Whiteboard:
Keywords:
Depends on: 532973
Blocks:
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Reported: 2017-02-06 14:34 EST by Joel Fernandes CLA
Modified: 2019-01-10 19:26 EST (History)
1 user (show)

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Description Joel Fernandes CLA 2017-02-06 14:34:08 EST 
Currently there's no display of C-state and CPU frequency information along with the CPU resources view Gantt chart. It will be particular useful to display this on every CPU (ever bar) of the CPU resources view Gantt chart.
Check:
http://lxr.free-electrons.com/source/include/trace/events/power.h

This is particularly useful for Embedded/battery-powered linux devices.
systrace can already do this. For systrace screenshots:
See image below for CPU frequency:
https://stuff.mit.edu/afs/sipb/project/android/docs/images/systrace/display-rhythm.png

See image below for C-state:
https://www.safaribooksonline.com/library/view/high-performance-android/9781491913994/assets/hpaa_0430.png

C-state can be a gantt chart with redness to indicate depth of C-state. But for CPU frequency, I feel it is better to show as X-Y view (or both X-Y view and Gantt)

Find me on IRC (joel_) if you'd like to discuss this.
Comment 1 Matthew Khouzam CLA 2019-01-10 19:26:08 EST 
Just a though, how about if the color is the c-state and the width is the frequency for the same entry?