Shannon V. Davidson wrote:
Michael H. Frese wrote:
At 08:31 AM 1/16/2008, Jeffrey B. Layton wrote:
- With multi-core processors, to get the best performance you want to
assign a process to a core.
Excuse my ignorance, please, but can someone tell me how to do that on
Linux (2.6 kernels would be fine)?
sched_setaffinity(2)
taskset(1)
numactl(1)
Hi,
As an aside to this, do 2.6 kernels make some efforts to keep a process
on a specific core anyways recognising the benefits to the cache of
doing so (I suspect they do but maybe I just dreamed it up)?
As a further aside, some MPI libraries (OpenMPI comes to mind) seem to
make some efforts to keep processes on the same cores also (or can be
instructed to via a run-time option).
I'm wondering how much of a performance benefit there is to using the
above-mentioned OS commands to set affinity (versus the trade-off in
setting this up).
-stephen
--
Stephen Mulcahy, Applepie Solutions Ltd., Innovation in Business Center,
GMIT, Dublin Rd, Galway, Ireland. +353.91.751262 http://www.aplpi.com
Registered in Ireland, no. 289353 (5 Woodlands Avenue, Renmore, Galway)
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