[Haskell-cafe] Re: hxt memory useage
bulat.ziganshin at gmail.com
Sat Jan 26 03:21:34 EST 2008
Friday, January 25, 2008, 10:49:53 PM, you wrote:
> Still I am a bit surprised that you can't parse 30m with 8 gig memory.
> This was discussed here before, and I think someone benchmarked HXT as using
> roughly 50 bytes of memory per 1 byte of input.
> i.e. HXT would then be using about 1.5 gig of memory for your 30m file.
to be exact, it's GHC by itself who use so many memory (on 64-bit
systems). the calculation is simple:
- one word (8 byte) for Char itself
- one word for tail pointer
- one word for laziness thunk
it's already 24 bytes. and depending on GC used, this amount increases
either 2x (with collecting GC) or 3x (with default, copying GC)
and HXT may add even more overhead, saving several copies of data or
building some lazy thunks on each char
Bulat mailto:Bulat.Ziganshin at gmail.com
More information about the Haskell-Cafe