[ET Trac] [Einstein Toolkit] #2059: SimFactory should detect the number of cores automatically

[Einstein Toolkit]

#2059: SimFactory should detect the number of cores automatically
--------------------------+-------------------------------------------------
  Reporter:  hinder       |       Owner:                     
      Type:  enhancement  |      Status:  review             
  Priority:  minor        |   Milestone:                     
 Component:  SimFactory   |     Version:  development version
Resolution:               |    Keywords:                     
--------------------------+-------------------------------------------------

Comment (by rhaas):

 This is a new branch, yes, not the one from the pull request
 (https://bitbucket.org/simfactory/simfactory2/pull-requests/20/simdtpy-
 detect-number-of-cpus/diff)?

 Comments:
 * on should not assume that lscpu is in /usr/bin/lscpu instead one should
 just make sure that output to stderr is captured as well as output to
 stdout and include both in the warning logged if there is an error. This
 likely needs more than just os.popen (see
 https://docs.python.org/2/library/subprocess.html#popen-constructor)
 * NumberOfCores is still incorrect eg on BW it should be 32 but the math
 in the patch gives 16 (and 16 is no sensible number of BW for any of the
 "core" related settings, 8 or 32 are)
 * NumberOfThreads is the correct number (based on how it is used later)
 but somewhat confusing. As it is the max-num-threads value (identical to
 ppn)
 * num-threads is set to NumberOfCores (also an odd name, cores per what?)
 which is computed as 16 which is wrong eg on BW where it should be 8

 Note that I am using BW as an example since it has a complex NUMA layout
 and has hyperthreading support as well (extra wrinkles).

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/2059#comment:10>
Einstein Toolkit <http://einsteintoolkit.org>
The Einstein Toolkit