[lttng-dev] userspace-rcu test scripts patches (was: ports/168339: [patch] sysutils/userspace-rcu update to 0.7.2

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Sun May 27 15:44:12 EDT 2012

* Mathieu Desnoyers (mathieu.desnoyers at efficios.com) wrote:
> > 
> > 
> >  #  btw, test_perthreadlock under FreeBSD 10-CURRENT always fails
> >  #  (releases prior to 9.0 are okay).

-> I guess you mean "releases up to, and including 9.0, are OK".

> >  #  The change in FreeBSD libthr might cause the error.
> >  #  I haven't looked into it yet.
> What are the details of your test invokation ? (how many reader/writer
> threads, how many cores do you have ? Is this on hardware or virtualized ?)

Actually, the most interesting thing to know here would be your
architecture. Moreover, as a hint, the fact that the problem seems to
only arise in the perthreadlock test, which generates a lot of
contention when the writer takes all the reader locks, I would guess
that the bug would sit somewhere in the contention handling code, which
could be either at the user-space library or kernel-level side.



> Thanks!
> Mathieu

Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.

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