[Numpy-discussion] High-quality memory profiling for numpy in python 3.5 / volunteers needed

Aron Ahmadia aron at ahmadia.net
Thu Apr 17 10:08:22 EDT 2014

> On the one hand it would be nice to actually know whether posix_memalign
is important, before making api decisions on this basis.

FWIW: On the lightweight IBM cores that the extremely popular BlueGene
machines were based on, accessing unaligned memory raised system faults.
 The default behavior of these machines was to terminate the program if
more than 1000 such errors occurred on a given process, and an environment
variable allowed you to terminate the program if *any* unaligned memory
access occurred.  This is because unaligned memory accesses were 15x (or
more) slower than aligned memory access.

The newer /Q chips seem to be a little more forgiving of this, but I think
one can in general expect allocated memory alignment to be an important
performance technique for future high performance computing architectures.


On Thu, Apr 17, 2014 at 9:09 AM, Nathaniel Smith <njs at pobox.com> wrote:

> On Wed, Apr 16, 2014 at 4:17 PM, R Hattersley <rhattersley at gmail.com>
> wrote:
> > For some reason the Python issue 21223 didn't show any activity until I
> > logged in to post my patch. At which point I saw that haypo had already
> > submitted pretty much exactly the same patch. *sigh* That was pretty
> much a
> > waste of time then. :-|
> Oh, that sucks :-(. I knew that there was a patch posted there, but I
> was travelling yesterday when you posted :-/.
> -n
> --
> Nathaniel J. Smith
> Postdoctoral researcher - Informatics - University of Edinburgh
> http://vorpus.org
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion
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