GHC-6.4.1 much slower than GHC-6.4

[Mirko Rahn]

> Below is my profiling data (on Linux turing 2.6.11.4-21.9-default)
> Any ideas?

>        interesting-ghc-6.4 +RTS -p -RTS
>     total time  =      253.76 secs   (12688 ticks @ 20 ms)
>     total alloc = 15,991,765,312 bytes  (excludes profiling overheads)
> transF                         NFA.Type              13.9    1.1

>        interesting-ghc-6.4.1 +RTS -p -RTS
>     total time  =     1020.74 secs   (51037 ticks @ 20 ms)
>     total alloc = 70,086,586,572 bytes  (excludes profiling overheads)
> transF                         NFA.Type              17.3    1.6

I have similar results, you can get it via

http://liinwww.ira.uka.de/~rahn/src/Interesting.6.4.prof.bin.prof
http://liinwww.ira.uka.de/~rahn/src/Interesting.6.4.1.prof.bin.prof

    Interesting.6.4.prof.bin +RTS -p -RTS
    total time  =      264.84 secs   (13242 ticks @ 20 ms)
    total alloc = 20,392,244,536 bytes  (excludes profiling overheads)
transF                         NFA.Type               6.9    2.4

    Interesting.6.4.1.prof.bin +RTS -p -RTS
    total time  =     1027.78 secs   (51389 ticks @ 20 ms)
    total alloc = 86,324,225,736 bytes  (excludes profiling overheads)
transF                         NFA.Type               8.9    3.4

As in your case, the 6.4.1-version allocs memory by about factor 4.3! I 
don't know why our profiles are pretty different but in my profiles the 
entry counts for some functions are much higher in the 6.4.1-version, 
e.G. 2559782 entries for Util.Words.isPartOf in 6.4-version and 10123468 
entries in 6.4.1-version, also about factor 4.

I guess the 6.4.1-version does more work, although I don't know why...

      Mirko

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