How to monitor the display framerate: Difference between revisions

Latest revision as of 09:43, 8 October 2024↑

Applicable for

STM32MP13x lines, STM32MP15x lines, STM32MP21x lines, STM32MP23x lines, STM32MP25x lines

1. Basic usage↑

When an animation is running on the display, the related framerate can be monitored from the display driver^[1] level thanks to the command:

(while true; do export fps=`cat /sys/kernel/debug/dri/0/state | grep fps -m1 | grep -o '[0-9]\+'`; echo display ${fps}fps; sleep 4; done) &

The display framerate is then periodically output in the user console in "fps" (frames per second):

display 50fps
display 50fps
display 50fps

2. Advanced usage↑

The display can be composed of several layers which can be refreshed independently. Associated framerates can be monitored from the display driver^[1] level thanks to the command:

(while true; do cat /sys/kernel/debug/dri/0/state | sed -nE '/user|plane-/p' | sed -e ':a;N;$!ba;s/\n\t//g;s/user_updates=/ /g;s/plane-/display layer/g;' | sed -e 's/^.\{,11\}//g'; sleep 4; done) &

The display layer framerates are then periodically output in the user console in "fps" (frames per second):

display layer0 60fps
display layer1 25fps
display layer2 30fps

3. Tips↑

Stop monitoring the display framerate with the command "kill -9 `ps -o ppid= -C sleep`". This command may not work depending on your system configuration (busybox ps features, sh shell configuration...). Alternative method is to use the command "fg" followed by "CTRL+C" in your terminal.
Debugfs^[2] configuration needs to be enabled in order to be able to monitor the display framerate thanks to the DRM/KMS framework^[1] debug directory "/sys/kernel/debug/dri".
Adjust the display framerate update period by modifying the "sleep" value (4 seconds in the above examples).
Use the dmesg^[3] command "dmesg -n8" to mix both user and kernel console outputs.

4. References↑

↑ ^{Jump up to: 1.0} ^1.1 ^1.2 DRM/KMS framework for display drivers
↑ Debugfs
↑ Dmesg and Linux kernel log

[drm-1] {Jump up to: 1.0} ^1.1 ^1.2 DRM/KMS framework for display drivers

[2] Debugfs

[3] Dmesg and Linux kernel log

[1]

[2]

[3]

@@ Line 1: / Line 1: @@
 <noinclude>
 {{ApplicableFor
-|MPUs list=STM32MP13x, STM32MP15x, STM32MP25x
+|MPUs list=STM32MP13x, STM32MP15x, STM32MP21x, STM32MP23x, STM32MP25x
-|MPUs checklist=STM32MP13x, STM32MP15x, STM32MP25x
+|MPUs checklist=STM32MP13x, STM32MP15x, STM32MP21x, STM32MP23x, STM32MP25x
 }}
 </noinclude>
@@ Line 8: / Line 8: @@
 == Basic usage ==
 When an animation is running on the display, the related framerate can be monitored from the display driver<ref name=drm>[[DRM KMS overview | DRM/KMS framework for display drivers]]</ref> level thanks to the command:
-  {{Board$}} (while true; do export fps=`cat /sys/kernel/debug/dri/0/state | grep fps -m1 | grep -o '[0-9]\+'`; echo display ${fps}fps; sleep 4; done) &
+  {{board$}}(while true; do export fps=`cat /sys/kernel/debug/dri/0/state | grep fps -m1 | grep -o '[0-9]\+'`; echo display ${fps}fps; sleep 4; done) &
 The display framerate is then periodically output in the user console in "fps" ('''f'''rames '''p'''er '''s'''econd):
@@ Line 19: / Line 19: @@
 == Advanced usage ==
 The display can be composed of '''several layers''' which can be refreshed independently. Associated framerates can be monitored from the display driver<ref name=drm/> level thanks to the command:
-  {{Board$}} (while true; do cat /sys/kernel/debug/dri/0/state | sed -nE '/user|plane-/p' | sed -e ':a;N;$!ba;s/\n\t//g;s/user_updates=/ /g;s/plane-/display layer/g;' | sed -e 's/^.\{,11\}//g'; sleep 4; done) &
+  {{board$}}(while true; do cat /sys/kernel/debug/dri/0/state | sed -nE '/user|plane-/p' | sed -e ':a;N;$!ba;s/\n\t//g;s/user_updates=/ /g;s/plane-/display layer/g;' | sed -e 's/^.\{,11\}//g'; sleep 4; done) &
 The display layer framerates are then periodically output in the user console in "fps" ('''f'''rames '''p'''er '''s'''econd):