Re: [RFC][PATCH 5/7] sched,livepatch: Use wake_up_if_idle()

Miroslav Benes
2021-09-22T13:05:06Z

> @@ -405,8 +405,10 @@ void klp_try_complete_transition(void)
> for_each_possible_cpu(cpu) {
> task = idle_task(cpu);
> if (cpu_online(cpu)) {
> - if (!klp_try_switch_task(task))
> - complete = false;
> + int ret = klp_try_switch_task(task);
> + if (ret == -EBUSY)
> + wake_up_if_idle(cpu);
> + complete = !ret;

This is broken. You can basically change "complete" only to false (when it
applies). This could leave some tasks in the old patching state.

Anyway, I like the patch set a lot. It moves our infrastructure to a
proper (I hope so) API and it removes few quirks we have along the way.
I'll play with it some more.

Thanks

Miroslav