[Beowulf] Again about NUMA (numactl and taskset)
patrick at myri.com
Thu Jun 26 23:39:39 PDT 2008
Håkon Bugge wrote:
> This is information we're using to optimize how pnt-to-pnt communication
> is implemented. The code-base involved is fairly complicated and I do
> not expect resource management systems to cope with it.
Why not ? It's its job to know the resources it has to manage. The
resource manager has more information than you, it does not have to
detect at runtime for each job, and it can manage cores allocation
across jobs. You cannot expect the granularity of the allocation to stay
at the node level with the core count increasing.
If the MPI implementation does the spawning, it should definitively have
support to enforce core affinity (most do AFAIK). However, core affinity
should be dictated by the scheduler. Heck, the MPI implementation should
not do the spawning in the first place.
Historically, resource managers have been pretty dumb. These days, there
is enough competition in this domain to expect better.
More information about the Beowulf