[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Intermittent parallel test failures

From: Ralf Wildenhues
Subject: Re: Intermittent parallel test failures
Date: Sun, 16 Nov 2008 18:23:43 +0100
User-agent: Mutt/1.5.18 (2008-05-17)

Hi Bob,

* Bob Proulx wrote on Sat, Nov 15, 2008 at 04:36:01AM CET:
> Ralf Wildenhues wrote:
> > Thanks for the report.  This is a different type of failure than the
> > last one, I'm glad.  It is of the kind of the lost race inherent and
> > unavoidable in the test: trying to find out whether parallel execution
> > really is faster than sequential, is not deterministically possible
> > on non-real-time systems.
> And will have quite different results on single cpu versus multi cpu
> systems.

Not as much as it may seem: the tests all consist of 'sleep 1' calls.
As long as the system is fast enough that the Autotest overhead per test
group is small compared to one second, a single cpu system should have
no problem with it.

> > Was the system very loaded at the time?
> I do not know and do not keep records to be able to correlate it.
> For this type of test perhaps it could be reasonable to gather this
> information dynamically?  (e.g. with uptime)  Useful debug info...

Good idea.

> > Note I'm not suggesting to make it less so; au contraire, this test
> > part should either be disabled or made even less prone to failure in
> > that case.  This is the first such failure in surely a lot of test
> > runs.
> If it is a different test failure then it certainly has had a lot of
> test runs without producing this failure.

Yes.  And I have never been able to provoke it myself, even on a very
loaded system like 'make check TESTSUITEFLAGS=-j'.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]