I’m seeing some pretty disappointing CPU usage from a low throughput coroutines workload (sending ~40-50 network requests per second) that is all non-blocking I/O, barely any CPU work. Using the async profiler shows the DefaultDispatcher threads are spending the majority of their time in the coroutines scheduler (mostly in

Worker.doPark

or

WorkQueue.trySteal

. Is this… expected?

I don't understand your question, you say you are disappointment in CPU usage and you say you you have tasks that do barely any CPU work. Seems like a contradiction to me. If the tasks are IO bound then I would expect all the threads to be parked doing nothing.

My point is that the coroutine scheduler itself is using much more CPU than I would expect

When your code is mainly waiting for IO, then the percentage of time spent in the scheduler will go up because nothing else are running.

@elizarov @Vsevolod Tolstopyatov [JB] is it possible this branch will improve things? https://github.com/Kotlin/kotlinx.coroutines/tree/scheduler-changes

yes, that's its point :)

👍

(sending from my phone, so can't give more detailed instructions) you can comment out all native targets from https://github.com/Kotlin/kotlinx.coroutines/blob/master/gradle/compile-native-multiplatform.gradle

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