Memory Bandwidth used when running Qt-Web Browser

[zhencongtee]

Hi all,

I am running Yocto on the i.mx6 Solo CPU. The default image comes with a QT web browser.

Is there any way we can calculate the memory bandwidth used when we are running the QT web browser?

For example, i am running a html5 testing using the below page:

http://ie.microsoft.com/testdrive/performance/fishbowl/

I get the CPU load is 100% from 'top' command. From the page i can see the frame/second while running the page.

But how can i calculate the memory bandwidth while running this page?

Many thanks.

Regards,

Zhen Cong Tee

[igorpadykov]

Hi Zhen

unfortunately there is no way to accurately calculate the memory bandwidth, since

there are many unknown factors. In general one can use MMDC profiling

feature described in sect.44.7 "MMDC Profiling"

IMX6DQRM  i.MX 6Dual/6Quad Applications Processor Reference Manual

Best regards

chip

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[zhencongtee]

Hi chip,

Thanks for the reply.

If that is the case, is there any tools in yocto that we can use to see the memory utilization of each process running?

Besides running the browser, i had tried to do some decoding on full HD video and display through HDMI. It would be nice if we can actually see what is the memory usage especially during the time where the decoding is being carried out.

Thank you.

Regards,

Zhen Cong Tee

[igorpadykov]

Hi Zhen

I think no.

As I already said "memory utilization" is quite complicated subject

for calculation and even measuring by any tools.

There are too many data streams and modules (such as for example

Network Interconnect Bus System (NIC-301)) involved in memory bandwidth

mechanizms. Some of these modules are actually small processor (for example SDMA).

One can try experimentally what use case [means HD video +

ethernet + audio + smth. else] will provide better results.

Best regards

chip

[zhencongtee]

Hi Chip,

If that is the case, is there any document that i can find some theoretical calculation on the memory bandwidth when using the components of the i.mx6 SOLO, such as the GPU, VPU, IPU etc?

Thank you.

Regards,

Zhen Cong Tee

[igorpadykov]

Hi Zhen

there are good IPU,VPU FTF presentations below, FTF-CON-F0223,FTF-CON-F0119

https://www.freescale.com/webapp/Download?colCode=FTF-CON-F0119&location=null&Parent_nodeId=&Parent_...

Freescale Technical Sessions Library

https://www.freescale.com/webapp/Download?colCode=FTF-CON-F0223&location=null&Parent_nodeId=&Parent_...

for other modules, sorry I believe there are no similar documents.

One can look at RM for bandwidth estimations.

Best regards

chip