[Haskell-cafe] Threading and Mullticore Computation
andrewcoppin at btinternet.com
Tue Mar 3 13:28:30 EST 2009
Svein Ove Aas wrote:
> For what it's worth, I tried it myself on 6.10.. details follow, but
> overall impression is that while you lose some time to overhead, it's
> still 50% faster than unthreaded.
Damn. Somebody beat me to it. :-)
> While trying to optimize it, I ran "./test +RTS -N2 -H64m -M64m"; the
> program promptly ate all my memory, invoking the OOM killer and
> messing up my system something fierce. This has to be a bug.
I should point out that approximately 50% of the time, the -N2 version
exits with "Cores1: out of memory" rather than running to completion.
The -N1 version never does this.
I hadn't looked at RAM usage, but it does appear that both programs
use... rather a lot of this. (Measurable in gigabytes.) Space leak,
anyone? (Presumably in fac or fac'.)
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