Hi, yes, you can use system property kotlinx.coroutines.scheduler=off in order to switch default dispatcher to ForkJoinPool. But in Ktor that dispatcher is used unconditionally, so the only option is to switch CIO engine to Netty or Jetty.
Thanks for the feedback, we will fix it under Dispatchers.Default consumes too much CPU in the face of short bursts of work · Issue #840 · Kotlin/kotlinx.coroutines · GitHub