Hi guys,
I need a little help understanding the solving a performance issue.
We are running ardupilot with beagle(green and black) with 4.14.226 rt kernel, and there is a service on systemd to start the ardupilot code.
We use a DTB with all devices(Uarts, SPI, CAN, I2C) and this dtb is loaded at boot time.
In this scenario, the system load average is hudge - up to 15 with processor at 100% all the time.
After several analisys I found the main reason of the problem. If the ardupilot code starts in the same time or meanwhile there are systemd-udevd activities, this performance problem happens.
If I wait all the activity stop, the process run without problem.
Once I’m using a DTB, is really necessary this systemd-udevd run ?
There is a way to check when this systemd-udevd end their work to start ardupilot process?
This is a sample process running:
1833 ? Rs 0:02 /lib/systemd/systemd-udevd
1839 ? S 0:00 _ /lib/systemd/systemd-udevd
1840 ? S 0:00 _ /lib/systemd/systemd-udevd
1841 ? R 0:00 _ /lib/systemd/systemd-udevd
1843 ? S 0:00 _ /lib/systemd/systemd-udevd
4793 ? R 0:00 | _ /bin/chgrp -R gpio /sys/devices/platform/ocp/47400000.usb/47400000.dma-controller/dma/dma2chan26
1847 ? S 0:00 _ /lib/systemd/systemd-udevd
4794 ? D 0:00 | _ /bin/chgrp -R gpio /sys/devices/platform/ocp/47400000.usb/47400000.dma-controller/dma/dma2chan31
1849 ? S 0:00 _ /lib/systemd/systemd-udevd
4796 ? R 0:00 | _ /bin/chgrp -R gpio /sys/devices/platform/ocp/47400000.usb/47400000.dma-controller/dma/dma2chan27
1850 ? R 0:00 _ /lib/systemd/systemd-udevd
1852 ? S 0:00 _ /lib/systemd/systemd-udevd
1865 ? S 0:00 _ /lib/systemd/systemd-udevd
4797 ? R 0:00 | _ /bin/chmod -R g=u /sys/devices/platform/ocp/47400000.usb/47400000.dma-controller/dma/dma2chan28
1869 ? S 0:00 _ /lib/systemd/systemd-udevd
this is the version.sh
root@beaglebone:~# /opt/scripts/tools/version.sh
git:/opt/scripts/:[80d937707b4c91677fbacc2be59d6000c7bad008]
eeprom:[A335BNLTBBG1BBG217100838]
model:[TI_AM335x_BeagleBone_Black]
dogtag:[BeagleBoard.org Debian Stretch Console Image 2021-02-15]
bootloader:[microSD-(push-button)]:[/dev/mmcblk0]:[U-Boot SPL 2019.04-00002-gc9b3922522 (Aug 24 2020 - 16:42:18 -0500)]:[location: dd MBR]
bootloader:[microSD-(push-button)]:[/dev/mmcblk0]:[U-Boot 2019.04-00002-gc9b3922522]:[location: dd MBR]
kernel:[4.14.226-bone-rt-r49]
device-tree-override:[dtb=am335x-agroraptor.dtb]
/boot/uEnv.txt Settings:
pkg check: to individually upgrade run: [sudo apt install --only-upgrade ]
pkg:[bb-cape-overlays]:[4.14.20210416.0-0~stretch+20210416]
pkg:[bb-customizations]:[1.20210225.0-0~stretch+20210225]
pkg:[bb-usb-gadgets]:[1.20200504.0-0~stretch+20200504]
pkg:[bb-wl18xx-firmware]:[1.20200813.1-0~stretch+20200813]
pkg:[kmod]:[23-2rcnee1~stretch+20171005]
WARNING:pkg:[librobotcontrol]:[NOT_INSTALLED]
pkg:[firmware-ti-connectivity]:[20190717-2rcnee1~stretch+20200305]
groups:[debian : debian adm kmem dialout cdrom floppy audio dip video plugdev users systemd-journal input bluetooth netdev gpio admin spi iio i2c docker tisdk weston-launch xenomai cloud9ide pwm eqep remoteproc]
cmdline:[console=ttyO0,115200n8 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 lpj=1990656 rng_core.default_quality=100 quiet]
dmesg | grep remote
[ 0.718817] remoteproc remoteproc0: wkup_m3 is available
[ 0.777072] remoteproc remoteproc0: powering up wkup_m3
[ 0.777121] remoteproc remoteproc0: Booting fw image am335x-pm-firmware.elf, size 217148
[ 0.777367] remoteproc remoteproc0: remote processor wkup_m3 is now up
dmesg | grep pru
dmesg | grep pinctrl-single
[ 0.499121] pinctrl-single 44e10800.pinmux: 142 pins at pa f9e10800 size 568
dmesg | grep gpio-of-helper
[ 0.500030] gpio-of-helper ocp:cape-universal: ready
END