On 06/20/2017 12:53 PM, Chris Friesen wrote:
On 06/20/2017 06:29 AM, Jay Pipes wrote:
On 06/19/2017 10:45 PM, Zhenyu Zheng wrote:
Sorry, The mail sent accidentally by mis-typing ...
My question is, what is the benefit of the above preference?
Hi Kevin!
I believe the benefit is so that the compute node prefers CPU
topologies that do
not have hardware threads over CPU topologies that do include hardware
threads.
I'm not sure exactly of the reason for this preference, but perhaps it
is due to
assumptions that on some hardware, threads will compete for the same
cache
resources as other siblings on a core whereas cores may have their own
caches
(again, on some specific hardware).
Isn't the definition of hardware threads basically the fact that the
sibling threads share the resources of a single core?
Are there architectures that OpenStack runs on where hardware threads
don't compete for cache/TLB/execution units? (And if there are, then
why are they called threads and not cores?)
I've learned over the years not to make any assumptions about hardware.
Thus my "not sure exactly" bet-hedging ;)
Best,
-jay
__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: [email protected]?subject:unsubscribe
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
