[GHC] #14256: GHCi is faster than compiled code

[GHC]

#14256: GHCi is faster than compiled code
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        Reporter:  mpickering        |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by saep):

 I think the problem is with the benchmarking tool. I used apache bench and
 got the same results as above. Just today, a colleague recommended to use
 wrk (https://github.com/wg/wrk) for benchmarking and with it, the compiled
 binary was always faster.

 I initially suspected that the threaded runtime of the compiled binary
 could have been responsible for the slow-down because running the server
 from ghci only occupied 1 core whereas the binary used all my 8(ish)
 cores. When I only use "-O2" and not "-O2 -threaded -rtsopts -with-
 rtsopts=-N", the apache bench measurements of the compiled binary were, as
 intuitively expected, better than the ghci ones.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14256#comment:4>
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