GPU not being used?

[AdamWeiss]

I'm not sure how to debug this.
I've been working on an application for quite some time, and it's been working fine.
It uses 25% CPU, and uses the GPU for 2D rendering (from SFML/OpenGL).

I copied the image off my SD card and wrote it to a larger SD card.
In the process, I changed one file (boot_config.txt) because I had a bug in the old copy.

However, now I'm using 95% CPU.
And when I do a top -H, I can see my threads are spending all their time in llvmpipe, which suggests that the CPU is doing all the rendering.

Any ideas on how I can begin to debug this?
I still have the old SD card.

Thanks!

[wildfire]

The answer's in the question.

What changed?

[bensimmo]

What OS?

If Raspian are you using the beta 3D driver.
Did you update the system.

What did you remove from that file?

[AdamWeiss]

Well, a little digging.
For some reason, I had to re-enable the GL driver from raspi-config.
Once I did that, it worked, and I'm back to 25% CPU.

One thing that's weird though.
I'm using the official LCD, and no matter what, I can't get the screen to rotate.

Previously, putting "rotate_display=2" would fix that.
But now it seems that it's being ignored.

The line I had removed from the config.txt was "gpu_memory=6"....I apparently had started to make a change, and it got left in there.
With that line in there, the system would not boot on the LCD screen, but would on HDMI.
I've been debugging 2 issues. First was the LCD not booting (I just switched to using it, and got that figured out).
Second was this.

So, I'm almost 100% back up and running.
I'm running and booting successfully with the LCD, GL is working, but screen won't rotate.

[AdamWeiss]

Apparently, lcd_rotate=2 is different from display_rotate=2.
At least with the experimental GL driver.

After making that change, everything is working!