[petsc-dev] Fwd: Nightly tests quick summary page

Matthew Knepley knepley at gmail.com
Thu Jan 24 09:55:21 CST 2013

On Thu, Jan 24, 2013 at 9:47 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> On Thu, Jan 24, 2013 at 9:39 AM, Karl Rupp <rupp at mcs.anl.gov> wrote:
>> Testing for the same number of iterations is - as you mentioned - a
>> terrible metric. I see this regularly on GPUs, where rounding modes differ
>> slightly from CPUs. Running a fixed (low) number of iterations is certainly
>> the better choice here, provided that the systems we use for the tests are
>> neither too ill-conditioned nor too well-behaved so that we can eventually
>> reuse the tests for some preconditioners.
> That's something that certainly makes sense for tests of functionality,
> but not for examples/tutorials that new users should encounter, lest they
> get the impression that they should use such options.
> Do you have much experience with code coverage tools? It would be very
> useful if we could automatically identify which tests were serving no
> useful purpose. The amount of time taken by make alltests is currently
> unreasonable, and though parallel testing will help, I suspect there are
> also many tests that could be removed (and time-consuming tests that could
> be made much faster without affecting their usefulness).

Satish had gcov working before, but it just did not prove to be very
useful. First, we generally write tests
to look at the workflow for something rather than as a unit test. Second,
coverage ignores the path you
take to get to a certain line of code. My impression is that these things
are only useful when they tell you
lines which are never exercised.


What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20130124/44b4245e/attachment.html>

More information about the petsc-dev mailing list