[GHC] #11075: Confusing parallel spark behaviour with safe FFI calls

[GHC]

#11075: Confusing parallel spark behaviour with safe FFI calls
-------------------------------------+-------------------------------------
        Reporter:  duncan            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Runtime System    |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by simonmar):

 Oh, I actually implemented this a while ago as an experiment.  I called it
 `foreign import "nonblocking"`, the idea is very simple: just release the
 capability but don't wake up another worker.  It's not perfect, we could
 still get a worker woken up under some circumstances, but I bet it would
 help.  I'll dig up the patch and see if we can get it in.

 Also, what on earth are you doing making FFI calls from sparks :-)

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11075#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler