[Haskell-cafe] Automatic parallelism in Haskell, similar to "make -j4"?

Bulat Ziganshin bulat.ziganshin at gmail.com
Mon Nov 3 02:47:30 EST 2008


Hello T,

Monday, November 3, 2008, 3:42:49 AM, you wrote:

> On Sun, Nov 2, 2008 at 6:44 PM, Bulat Ziganshin
> <bulat.ziganshin at gmail.com> 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"?

are you ever herd about "halting problem"? it's imposible in general
case and i doubt how far it may be done on practice. in general, it
looks close to really compute the function (and you still need to know
its actual input params!)

anyway it's not done and i don't heard about researches in this
direction


-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com



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