some opensource rtos not fit me

[ares qi]

there is some good opensource rtos which are not fit me , i think

That's because it is not very popular, little discuss or others reasons.

uSmartX rtmk ROME

pico]OS (complex, a lot of marcros , use bit maps like ucos instead of
links like freertos)

XMK (use plenty of files and directories to avoid #if #else #endif
and every public functions and variables have a map to a private
symbol. But i think the file hiarachy is too complex for a rtos and
isn't easy to understand. And it isn't popular too and have little
discuss)

prex(it's has a wonderful microkernel design, but it's in it's initial
stage and have little app and driver so i think maybe i should study
it after some time)