HEAD: Deterioration in ByteString I/O

[Don Stewart]

simonpj:
> |  > ghc-6.12.3:
> |  >       89,330,672 bytes allocated in the heap
> |  >           15,092 bytes copied during GC
> |  >           35,980 bytes maximum residency (1 sample(s))
> |  >           29,556 bytes maximum slop
> |  >                2 MB total memory in use (0 MB lost due to fragmentation)
> |  >
> |  > ghc-6.13.20100831:
> |  >      475,305,720 bytes allocated in the heap
> |  >           89,272 bytes copied during GC
> |  >           68,860 bytes maximum residency (1 sample(s))
> |  >           29,444 bytes maximum slop
> |  >                2 MB total memory in use (0 MB lost due to fragmentation)
> |  
> |  Can you put your benchmark code somewhere?  Likely a GHC regression.
> 
> Indeed bad. If someone could characterise the regression more
> precisely (e.g. "fusion isn't happening here") that would be jolly
> helpful. 

Shouldn't be fusion. Is this a straight IO function. Something to do
with buffering/encoding?