t.r.willingham: > On Sun, Nov 2, 2008 at 6:44 PM, Bulat Ziganshin > <[EMAIL PROTECTED]> wrote: > >> What would it take to implement a -j equivalent for, say, GHC? Or if > >> this is not possible, what is wrong with my reasoning? > > > > problem is that make have rather large pices of work which it can run > > parallel. if ghc will try to parallel every machine operation, it will > > pend more time maintaining these jobs. 'par' is just the way to tell > > GHC "this part of job is large enough" > > Right, but couldn't the Haskell complier+runtime discover "rather > large pieces of work"?
Requires runtime profiling to work out the costs. See this paper which implements this this idea, PDF http://research.microsoft.com/~tharris/papers/2007-fdip.pdf HTML http://209.85.173.104/search?q=cache:7cC4fQjCEH4J:research.microsoft.com/~tharris/papers/2007-fdip.pdf Note that for subsets of Haskell, where we have more information statically about the costs involves, we can do the parallelism automatically. Data Parallel Haskell is the prime example. -- Don _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe