LVGL performance dropped when migrating from zephyr v2.7 to v4.0/4.1.

[glory-man]

I use imxrt1060-based board with connected 768x1024 display. After migration to new Zephyr versions which uses v8(v9) LVGL instead of v7.6 UI performance dropped 2-3 times. Structure of UI-project fundamentally has not changed - where I could I refactored, where methods changed I replaced them with suitable ones. System configuration - for example CPU freq - the same as in zephyr 2.7. But the time required to render images has increased significantly.

some info at LVGL forum.

Maybe i missed something. How can i improve performance?

UPD: All data - OS heap, LVGL heap, files content - are stored in external SDRAM, accessing via SEMC.

[JairGudino]

Hi!

After reading your information, I don’t have a specific solution, but I do have some suggestions to help improve performance:

Double Frame Buffer: LVGL supports using a double frame buffer to reduce processing time. Make sure this feature is enabled.
Frame Buffer Location: You can move the frame buffer to SRAM for better performance. This application note can serve as a reference. https://www.nxp.com/docs/en/application-note/AN14597.pdf
Main Stack Size: Increasing the main stack size might help in some cases, although your issue may not be directly related to it.
Frame Buffer Rotation: If you're rotating the frame buffer to change the display orientation and the PXP is disabled, processing time could increase significantly.
I hope these suggestions help!