[Haskell-cafe] Can't get any memory profile data

[Edward Z. Yang]

The program is running too quickly for any profiling to occur. You
can tell with the RTS option -S and looking to see if major collections
occur. Try increasing the amount of computation.

Edward

Excerpts from Cody Goodman's message of 2016-03-11 20:54:43 -0800:
> Here is the command line log of my attempt following real world haskell's
> memory profiling example:
> 
> src λ stack exec -- ghc --version
> The Glorious Glasgow Haskell Compilation System, version 7.10.3
> src λ cat Main.hs
> module Main where
> 
> main :: IO ()
> main = do
>   let x = {-# SCC sum #-}sum [1..500]
>   print x
>   {-# SCC helloworld #-} putStrLn "hello world"
> src λ stack exec -- ghc -O2 --make Main.hs -prof -auto-all -caf-all
> -fforce-recomp
> [1 of 1] Compiling Main             ( Main.hs, Main.o )
> Linking Main ...
> src λ ./Main +RTS -hc -p
> 125250
> hello world
> src λ cat Main.hp
> JOB "Main +RTS -hc -p"
> DATE "Fri Mar 11 22:51 2016"
> SAMPLE_UNIT "seconds"
> VALUE_UNIT "bytes"
> BEGIN_SAMPLE 0.00
> END_SAMPLE 0.00
> BEGIN_SAMPLE 0.00
> END_SAMPLE 0.00