[GHC] #12181: Multi-threaded code on ARM64 GHC runtime doesn't use all available cores

[GHC]

#12181: Multi-threaded code on ARM64 GHC runtime doesn't use all available cores
--------------------------------------------+------------------------------
        Reporter:  varosi                   |                Owner:
            Type:  bug                      |               Status:  new
        Priority:  normal                   |            Milestone:
       Component:  Runtime System           |              Version:  7.10.3
      Resolution:                           |             Keywords:
Operating System:  Unknown/Multiple         |         Architecture:  arm
 Type of failure:  Runtime performance bug  |            Test Case:
      Blocked By:                           |             Blocking:
 Related Tickets:                           |  Differential Rev(s):
       Wiki Page:                           |
--------------------------------------------+------------------------------

Comment (by varosi):

 @thomie, yes, initially this 4 core machine is reporting only 1 active
 core. And as @rwbarton said, it is not a problem of GHC. So -N will not
 work correctly on that machine and we have to tell it explicitly 4 cores.
 It is actually tablet machine, so it save power with turning off cores.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12181#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler