STM32MP1 Browser Performance

Tasks of the GPU

• For „simple“ webpages without 3D-features, the GPU is only used for „blitting“during a process step called „Raster(ization) and Compositing“
• „blitting“ = fast copy and move of memory objects
• By this, a strong relief of the CPU can be achieved
• this should be well possible with the STM32MP1

Performance Tests

"Infragistics Ignite UI" Demo Application

The "Infragistics Ignite UI" is a commercial WebUI framework based on Angular.
To test the browser perfomance a WebUI based on that framework was used.

To open the screen in the above screenshot it takes approx. 3 seconds from menu click until content is fully visible

To get some insights the chromium profiling was used. The Chrome Profiler shows following things:

• the CPU does most of the work
• there is no obvious point where CPU cycles would be spent excessively (perf doesn't indicate anything).
• approx. 70% of the time is spent interpreting Javascript. This is also to be expected, since this angular is full of complex Javascript.
• But that also means the slowness is caused by the CPU / website
• not much the GPU can do about this.

Line-Chart Demo Application

with GPU

https://www.dropbox.com/s/323nv90lhp9wh02/mit_GPU.MP4?dl=0

no GPU

https://www.dropbox.com/s/kprvgowf8kzod6a/ohne_GPU.MP4?dl=0

DH demo from tradeshow

https://www.dropbox.com/s/rzeu2qk95oxy4lw/sensorless_demo_filtered_idastroem_DH%20electronics.mp4?dl=0

Profiling with Chrome DevTools

Chrome DevTools is a set of web developer tools built directly into the Google Chrome browser. It is possible to analyse the runtime performance of a website directly on the target or remote with an PC connected over ethernet. With an remote connection you can measure the performance without interfering the measurment itself. The Chrome DevTools can also be used with an qtWebengine.

How to use Chrome DevTools with an remote connection

To be able to remote debug chromium on the target you need to start the chromium or qWebengine with the following parameters:
-remote-debugging-port=9222 --user-data-dir=remote-profile

To access it from a different computer you need to forward the port with ssh:
ssh -L 0.0.0.0:9223:localhost:9222 localhost -N
This must be done before the webbrowser gets started.

With an Chrome Browser on an computer connected with the target over ethernet you can now open the devtools with the IP of the target and the port "9223".
This clip shows you how to open den chrome devtools: devtools-open.mp4

DevTools analysis

The following tools can be used for performance anlaysis:

• CPU Usage:
  

With this stat you can easily see when the CPU is under full load.

• GPU Usage:

The graph shows when the GPU is under use. But it does not show the GPU load in percent.

It is a useful tool to see if the GPU is fully ocupied.

If the GPU is disabled (software rendering) this graph is absent.

• Frame Rendering Stats:

Newer chrome versions don't show live FPS anymore. But you can us "dropped" or "delayed" frames as indicator for good or bad performance. The higher the percentage value (frames rendered in time) the better.

A good explanation can be found here:

https://groups.google.com/a/chromium.org/g/blink-dev/c/iHULoSyUxOQ

• Performance Profile:

The performance profile gives you an overview over all important stats at once. You can record it while browsing through an website on the target.

You can save such profiles and import it with any other chrome browser to analyse the profile offline.

Brief summary

• Webapplications must be optimized for particular embedded system resp. SOC
• Comprehensive analysis and profiling tools are available
• Thus, appealing web pages on embedded systems should be possible
• … where also the “responsiveness" is given