I've started recording of sound (minor CPU, memory and IO load) as
schedtool -R -p 2 -e arecord -f cd > qqq5.wav
And perform large compilation (high CPU load + high memory load + high IO load) as this:
schedtool -D -e nice -n 19 ionice -c3 make
Why does it "overrun!!! (at least -1770319440.252 ms long)" and spoil the recording? Why IDLE_PRIO and idle-io-class dare to mangle tasks with a realtime priority?
How to start heavy-weight thing as really low priority? It is allowed to thrash in a swap as it wants, but without interfering important things!
P.S. and running out of memory to OOM killer certainly produces "overrun!!!" every time...