Messages in this thread | | | Date | Mon, 9 Feb 2015 18:28:19 +0100 | From | Radim Krčmář <> | Subject | Re: [PATCH] kvm: add halt_poll_ns module parameter |
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2015-02-09 17:10+0100, Paolo Bonzini: > On 09/02/2015 16:21, Radim Krčmář wrote: > > 2015-02-06 13:48+0100, Paolo Bonzini: > >> +TRACE_EVENT(kvm_vcpu_wakeup, > >> + TP_PROTO(__u64 ns, bool waited), > > > > (__u64 is preferred here?) > > Preferred to what?
To 'u64'. (The header file shouldn't be reachable from user-space.)
> >> + } while (single_task_running() && ktime_before(cur, stop)); > > > > After reading a bunch of code, I'm still not sure ... > > - need_resched() can't be true when single_task_running()? > > (I think it could happen -- balancing comes into mind.) > > Single_task_running is per-CPU; for a task to relinquish control to > another task, you first need to have multiple tasks running. In other > words, I think it cannot.
Ok, thanks. (I thought that need_resched has more general meaning and couldn't confirm that balancing/CPU-offlining/... just evicts the task without waiting for its schedule().)
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