Linux/DRA744: Linux Boot Time optimization & Graphic issue

Fabio Calabro

Part Number: DRA744

Tool/software: Linux

For an Instrument Cluster application we are working to Fastboot Linux. Our target is to enter on the init (in userspace) <300,400 ms.

Currently we are very close to the target, but we are to solve the follow issues:

we noticed that 300ms are spent freeing the high pages.

This happens very early during boot and is implemented in function free_highpages() - inside arch/arm/mm/init.c.

We tried postponing the action to userspace (see patch attached), after the launch of critical applications - in our case: pvrsrvctl, the weston compositor and the instrument cluster. However, using this method, the applications begin to suffer from lack of memory, even if the full high memory is visbile to the system (verified through cat /proc/meminfo). This can be in particular noticed visually, with high-speed graphics that slow down.

In our impression this could be due the SGX graphic fw that does not recognize the full memory then.

Can you comment how we can hack the kernel or the SGX fw to save this 300 ms and having the graphic still full functional?

Br,

Fabio

over 8 years ago

0 Yordan Kamenov over 8 years ago

TI__Mastermind 42515 points

Hi Fabio,

I have forwarded your question to graphics experts.

Can you just tell which SDK you use?

Regards,
Yordan

0 Fabio Calabro over 8 years ago in reply to Yordan Kamenov

Intellectual 320 points

Hi Yordan,

We did not get feedbacks here,

This is an urgent topic due the Fastboot optimization we need to do for our Instrument Cluster Application.

Can you please push this with the DSS experts?

BR, Fabio

0 Fabio Calabro over 8 years ago in reply to Fabio Calabro

Intellectual 320 points

We are using PROCESSOR-SDK-LINUX-AUTOMOTIVE 03_02_00_03

0 Subhajit Paul over 8 years ago in reply to Fabio Calabro

TI__Expert 7015 points

Does pvrsrvctl succeed in your usecase? I would suggest running kmscube instead of weston to test whether the SGX H/W or S/W is capable of handling the scenario.

Regards,

Subhajit

0 Francesco Valla over 8 years ago in reply to Subhajit Paul

Intellectual 570 points

Hi Subhajit,
I'm a collegue of Fabio.

Currently, with full memory freed on boot our system is able to run flawlessly. If we introduce the dereffed frreing of high memory, system slows down and freezes under heavy load (and this is noticeable in the graphics).

The function free_highpages actually takes 290ms of boot time; did you know a way to cut down this time without affecting the normal operation?

Thank you

Br,
Francesco

0 Subhajit Paul over 8 years ago in reply to Francesco Valla

TI__Expert 7015 points

Francesco,

Please let me know if pvrsrvctl works in you deferred free memory model. If pvrsrvctl works, you can launch kmscube, which has very low memory requirement. This step will help me understand whether the problem is in SGX driver or weston.

If the system fails as early as pvrsrvctl, then we will need to investigate it at the driver level.

Regards,
Subhajit

0 Francesco Valla over 8 years ago in reply to Subhajit Paul

Intellectual 570 points

Hi Subhajit,

sorry for the long delay due to vacations.

In our trials, pvrsrvctl always works.

Regards,

Francesco

0 Subhajit Paul over 7 years ago in reply to Francesco Valla

TI__Expert 7015 points

Francesco,

sorry for the late reply. I also wanted to know whether you can run kmscube?

Regards,

Subhajit

0 Francesco Valla over 7 years ago in reply to Subhajit Paul

Intellectual 570 points

Hi Subhajit,

yes, kmscube always works.

After another bit of debugging, the issue seems more linked to lack of memory for applications, rather than for graphic stack (we can observe the kernel killing application because of out of memory errors).

Regards,
Francesco

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Linux/DRA744: Linux Boot Time optimization & Graphic issue