[GHC] #1747: debugger: :trace is wasting time

[GHC]

#1747: debugger: :trace is wasting time
-----------------------+----------------------------------------------------
  Reporter:  simonmar  |          Owner:            
      Type:  bug       |         Status:  new       
  Priority:  low       |      Milestone:  6.8 branch
 Component:  GHCi      |        Version:  6.6.1     
  Severity:  minor     |       Keywords:            
Difficulty:  Unknown   |             Os:  Unknown   
  Testcase:            |   Architecture:  Unknown   
-----------------------+----------------------------------------------------
 When using `:trace`, executing is constantly switching between the main
 GHCi thread and the execution thread.  The main GHCi thread is a bound
 thread, whereas the other thread is an unbound thread, so these context
 switches are real OS-thread switches, consequently `:trace` wastes a lot
 of time context-switching.

 Perhaps the main GHCi thread in an unbound thread, or else `:trace` should
 fork an unbound thread before starting execution.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1747>
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