2015-05-27 10:13 GMT+02:00 Nathaniel Smith <[email protected]>: > On Tue, May 26, 2015 at 9:53 AM, Julian Taylor > <[email protected]> wrote: > > On 05/26/2015 04:56 PM, Matthew Brett wrote: > >> Hi, > >> > >> This morning I was wondering whether we ought to plan to devote some > >> resources to collaborating with the OpenBLAS team. > >> > >> > >> > >> It is relatively easy to add tests using Python / numpy. We like > >> tests. Why don't we propose a collaboration with OpenBLAS where we > >> build and test numpy with every / most / some commits of OpenBLAS, and > >> try to make it easy for the OpenBLAS team to add tests. Maybe we > >> can use and add to the list of machines on which OpenBLAS is tested > >> [1]? We Berkeley Pythonistas can certainly add the machines at our > >> buildbot farm [2]. Maybe the Julia / R developers would be interested > >> to help too? > >> > > > > Technically we only need a single machine with the newest instruction > > set available. All other cases could then be tested via a virtual > > machine that only exposes specific instruction sets (e.g. qemu which > > could technically also emulate stuff the host does not have). > > > > Concerning test generation there is a huge parameter space that needs > > testing due with openblas, at least some of it would need to be > > automated/fuzzed. We also need specific preconditioning of memory to > > test failure cases openblas had in the past, E.g. filling memory around > > the matrices with nans and also somehow filling openblas own temporary > > buffers with some signaling values (might require special built openblas > > if _MALLOC_PERTURB does not work). > > A lot of this stuff is easier if we take a white-box instead of > black-box approach -- adding hooks in OpenBLAS to override the > CPU-based kernel-autoselection sounds a lot easier than creating > unnatural machines in qemu, and similarly for initializing temporary > buffers. (I would be really unsurprised if OpenBLAS re-uses temporary > buffers across calls instead of doing a free/re-malloc, for example.) > > Manually overwriting the OpenBLAS CPU autoselection can easily be done by setting the OPENBLAS_CORETYPE environment variable, i.e. export OPENBLAS_CORETYPE=Nehalem
> > Maybe it would be feasible to write a hypothesis [0] strategy for some > > of the blas stuff to automate the parameter exploration. > > Or if this is daunting, you can get pretty far just sitting down and > writing some for loops... I think this is a case where something is a > lot better than nothing :-). > > -n > > -- > Nathaniel J. Smith -- http://vorpus.org > _______________________________________________ > NumPy-Discussion mailing list > [email protected] > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
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