On Thu, May 31, 2012 at 11:28 AM, Samuel Thibault <samuel.thibault@inria.fr> wrote:

Hello,

Vlad, le Thu 31 May 2012 16:49:00 +0200, a écrit :

> This might be a naive question, but I'd like to clarify nonetheless: to provide
> any sort of affinity guarantees, hwloc mem binding APIs assume that any memory
> allocation is done exclusively via hwloc_alloc_membind() and friends? And if I
> use "raw" calls to malloc() or posix_memalign() etc then any ensuing affinity
> will be incidental at best?

It seems the documentation lacks explanation about that indeed. I have
added the following text:

Memory binding can be done three ways:

- explicit memory allocation thanks to hwloc_alloc_membind and friends: the
binding will have effect on the memory allocated by these functions.
- implicit memory binding through binding policy: hwloc_set_membind and
friends only define the current policy of the process, which will be
applied to the subsequent calls to malloc() and friends.
- migration of existing memory ranges, thanks to hwloc_set_area_membind()
and friends, which move already-allocated data.

Does it answer your question? (i.e. the first way doesn't have effect on
malloc, while the second way does)

Samuel
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