I'm using a Totolink A8000RU, with MT7622 soc, and latest snaphot r19138-4ecf8346c0
i noticed since i'm using openwrt on this device that going in the Switch page in Luci takes a few seconds untill the page is displayed.
I started HTOP while doing it and just discovered that this command line was causing a big cpu load :
it's a dual core 1.35Mhz
When i manually run the command line, all the data are displayed, and while there is nothing more to display the cpu load goes to 60%, then 100% , and finaly i have the new prompt.
So the high cpu load is at the end, i don't know what it is trying to do, but all the necessary data are displayed immediatly.
And finaly i have the prompt, the command line finished running, back to 0% cpu load.
in the screenshot you can see it's not the same CPU# used, it's because i had to run the command 2 times to take the screenshots obviously it's the same CPU# used in all the steps.
Iirc it is a bug in the swconfig cli. It internally iterates all 4096 VLAN table slots in a busy loop instead of only inspecting the configured ones. Most likely not even a bug in the cli but in the switch specific backend driver.