[GHC] #15418: Performance drop 60 times on non-profiling binary

[GHC]

#15418: Performance drop 60 times on non-profiling binary
-------------------------------------+-------------------------------------
        Reporter:  hth313            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.6.1
       Component:  Runtime System    |              Version:  8.4.3
      Resolution:                    |             Keywords:
Operating System:  MacOS X           |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by hth313):

 Normal build (report using time)

 {{{
 real    16m17.687s
 user    16m1.916s
 sys     0m10.150s
 }}}

 Profiling build (no `+RTS -p`)

 {{{
 real    0m26.963s
 user    0m26.562s
 sys     0m0.378s
 }}}

 Profiling build, `+RTS -p`

 {{{
 real    0m27.528s
 user    0m27.121s
 sys     0m0.471s
 }}}

 Peeking inside generated `.prof`

 {{{
         total time  =       14.04 secs   (14037 ticks @ 1000 us, 1
 processor)
         total alloc = 17,827,853,336 bytes  (excludes profiling overheads)
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15418#comment:2>
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