[GHC] #14998: Sort out the strictness mess for exceptions

[GHC]

#14998: Sort out the strictness mess for exceptions
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.4.3
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:  Exceptions
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 sgraf):

 This is already reproducible for hello world. For the following program:

 {{{#!hs
 main = mapM_ (\_ -> putStrLn "hi") [0..10000]
 }}}

 we have this `+RTS -s` output under `-O2` (first HEAD, second with bangs
 removed in GHC.IO):

 {{{
        9,491,968 bytes allocated in the heap
           15,504 bytes copied during GC
           44,576 bytes maximum residency (2 sample(s))
           29,152 bytes maximum slop
                0 MB total memory in use (0 MB lost due to fragmentation)

                                      Tot time (elapsed)  Avg pause  Max
 pause
   Gen  0         8 colls,     0 par    0.000s   0.000s     0.0000s
 0.0000s
   Gen  1         2 colls,     0 par    0.000s   0.000s     0.0002s
 0.0002s

   INIT    time    0.000s  (  0.000s elapsed)
   MUT     time    0.005s  (  0.005s elapsed)
   GC      time    0.000s  (  0.000s elapsed)
   EXIT    time    0.000s  (  0.000s elapsed)
   Total   time    0.006s  (  0.006s elapsed)

   %GC     time       0.0%  (0.0% elapsed)

   Alloc rate    1,932,804,477 bytes per MUT second

   Productivity  89.2% of total user, 89.5% of total elapsed
 }}}

 {{{
       10,132,096 bytes allocated in the heap
           16,360 bytes copied during GC
           44,576 bytes maximum residency (2 sample(s))
           29,152 bytes maximum slop
                0 MB total memory in use (0 MB lost due to fragmentation)

                                      Tot time (elapsed)  Avg pause  Max
 pause
   Gen  0         8 colls,     0 par    0.000s   0.000s     0.0000s
 0.0000s
   Gen  1         2 colls,     0 par    0.000s   0.000s     0.0002s
 0.0003s

   INIT    time    0.000s  (  0.000s elapsed)
   MUT     time    0.007s  (  0.007s elapsed)
   GC      time    0.001s  (  0.001s elapsed)
   EXIT    time    0.000s  (  0.000s elapsed)
   Total   time    0.007s  (  0.007s elapsed)

   %GC     time       0.0%  (0.0% elapsed)

   Alloc rate    1,516,022,826 bytes per MUT second

   Productivity  89.6% of total user, 89.8% of total elapsed
 }}}

 So, the working set is affected, too, which I think is a necessary
 condition for a space leak.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14998#comment:14>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler