[Vm-dev] [Pharo-dev] Problem with OSSubprocess / signals / heartbeat ?

Ben Coman btc at openinworld.com
Sun Apr 2 00:10:58 UTC 2017


On Sun, Apr 2, 2017 at 3:11 AM, Petr Fischer <petr.fischer at me.com> wrote:

>
> > On Thu, 30 Mar 2017, Eliot Miranda wrote:
> >
> > > Once the active process is in a tight loop the delay is effectively
> > disabled because the tight loop effectively shuts out the heartbeat
> thread
> > and hence the system never notices that the delay has expired.
> >
> > I think that won't happen, because the process scheduler (O(1), CFS,
> BFS) on
> > linux is not cooperative. So, the kernel will periodically preempt the
> main
> > thread and run the heartbeat thread no matter what their priorities are.
> The
> > higher priority only provides lower jitter on the heartbeat thread.
> >
> > Levente
>
> Is there some test case or code, that I can run in Pharo and evaluate if
> kernel sheduler is working correctly (with heartbeat thread at normal
> priority).
> I need to test it under FreeBSD.
>
> Thanks! pf
>

Just for starters, what result do you get for my multi-priority fibonacci
stress test...
http://forum.world.st/Unix-heartbeat-thread-vs-itimer-tp4928943p4938456.html


cheers -ben
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